Posts Tagged ‘JetBrains’
[KotlinConf2023] KotlinConf’23 Closing Panel: Community Questions and Future Insights
KotlinConf’23 concluded with its traditional Closing Panel, an open forum where attendees could pose their burning questions to a diverse group of experts from the Kotlin community, including key figures from JetBrains and Google. The panel, moderated by Hadi Hariri, featured prominent names such as Roman Elizarov, Egor Tolstoy, Maxim Shafirov (CEO of JetBrains), Svetlana Isakova, Pamela Hill, Sebastian Aigner (all JetBrains), Grace Kloba, Kevin Galligan, David Blanc, Wenbo, Jeffrey van Gogh (all Google), Jake Wharton (Cash App), and Zac Sweers (Slack), among others.
The session was lively, covering a wide range of topics from language features and tooling to ecosystem development and the future of Kotlin across different platforms.
Kotlin’s Ambitions and Language Evolution
One of the initial questions addressed Kotlin’s overarching goal, humorously framed as whether Kotlin aims to “get rid of other programming languages”. Roman Elizarov quipped they only want to get rid of “bad ones,” while Egor Tolstoy clarified that Kotlin’s focus is primarily on application development (services, desktop, web, mobile) rather than systems programming.
Regarding Kotlin 2.0 and the possibility of removing features, the panel indicated a strong preference for maintaining backward compatibility. However, if a feature were to be considered for removal, it would likely be something with a clearly superior alternative, such as potentially older ways of doing things if newer, more robust mechanisms (like K2 compiler plugins replacing older KAPT mechanisms, hypothetically) became the standard. The discussion also touched on the desire for a unified, official Kotlin style guide and formatter to reduce community fragmentation around tooling, though Zac Sweers noted that even with an official tool, community alternatives would likely persist.
Multiplatform, Compose, and Ecosystem
A significant portion of the Q&A revolved around Kotlin Multiplatform (KMP) and Compose Multiplatform.
* Dart Interoperability: Questions arose about interoperability between Kotlin/Native (especially for Compose on iOS which uses Skia) and Dart/Flutter. While direct, deep interoperability wasn’t presented as a primary focus, the general sentiment was that both ecosystems are strong, and developers choose based on their needs. The panel emphasized that Compose for iOS aims for a native feel and deep integration with iOS platform features.
* Compose UI for iOS and Material Design: A recurring concern was whether Compose UI on iOS would feel “too Material Design” and not native enough for iOS users. Panelists from JetBrains and Google acknowledged this, stressing ongoing efforts to ensure Compose components on iOS adhere to Cupertino (iOS native) design principles and feel natural on the platform. Jake Wharton added that making Kotlin APIs feel idiomatic to iOS developers is crucial for adoption.
* Future of KMP: The panel expressed strong optimism for KMP’s future, highlighting its stability and growing library support. They see KMP becoming the default way to build applications when targeting multiple platforms with Kotlin. The focus is on making KMP robust and ensuring a great developer experience across all supported targets.
Performance, Tooling, and Emerging Areas
- Build Times: Concerns about Kotlin/Native build times, especially for iOS, were acknowledged. The team is continuously working on improving compiler performance and reducing build times, with K2 expected to bring further optimizations.
- Project Loom and Coroutines: Roman Elizarov reiterated points from his earlier talk, stating that Loom is excellent for migrating existing blocking Java code, while Kotlin Coroutines offer finer-grained control and structured concurrency, especially beneficial for UI and complex asynchronous workflows. They are not mutually exclusive and can coexist.
- Kotlin in Gaming: While not a primary focus historically, the panel acknowledged growing interest and some community libraries for game development with Kotlin. The potential for KMP in this area was also noted.
- Documentation: The importance of clear, comprehensive, and up-to-date documentation was a recurring theme, with the panel acknowledging it as an ongoing effort.
- AI and Kotlin: When asked about AI taking developers’ jobs, Zac Sweers offered a pragmatic take: AI won’t take your job, but someone who knows how to use AI effectively might. The panel highlighted that Kotlin is well-suited for building AI tools and applications.
The panel concluded with the exciting reveal of Kotlin’s reimagined mascot, Kodee (spelled K-O-D-E-E), a cute, modern character designed to represent the language and its community. Pins of Kodee were made available to attendees, adding a fun, tangible takeaway to the conference’s close.
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[KotlinConf2023] Compose Multiplatform on iOS: Sharing UIs Across Ecosystems with Sebastian Aigner and Nikita Lipsky
At KotlinConf’23, Sebastian Aigner (Developer Advocate at JetBrains) and Nikita Lipsky (Software Developer for Kotlin at JetBrains) presented an exciting overview of Compose Multiplatform, focusing on its then-Alpha support for iOS. Their session detailed how this JetBrains initiative enables developers to write their user interface once in Kotlin and deploy it across Android, iOS, desktop, and web, fostering significant code sharing and development efficiency. The official documentation for Compose Multiplatform offers further insights.
The presentation began by recapping the classic Kotlin Multiplatform (KMP) use case, which allows sharing of business logic while retaining access to platform-specific APIs. Compose Multiplatform builds upon this by providing a solution for sharing the UI layer itself, addressing scenarios where building and maintaining separate native UIs for each platform is not feasible due to time, resources, or the desire for rapid market entry. While the talk focused on iOS and Android, the speakers emphasized that Compose Multiplatform also supports desktop (stabilized in late 2021) and web targets.
Architecture and Jetpack Compose Foundations
A key point underscored by Sebastian and Nikita was that Compose Multiplatform is built upon Jetpack Compose, Google’s modern declarative UI toolkit for Android, which is 100% Kotlin. This means developers familiar with Jetpack Compose can leverage their existing knowledge and skills to build UIs for iOS and other platforms. The JetBrains team collaborates closely with Google, regularly upstreaming changes to the Jetpack Compose repositories.
Nikita Lipsky delved into the architecture, explaining that official Jetpack Compose itself is already a Kotlin Multiplatform project at its core, with its lowest levels defining Kotlin Multiplatform sources. The composable function concept is an extension to the Kotlin language requiring compiler support, and the entire Compose system is managed by the Compose Runtime. For iOS, Compose Multiplatform renders UI elements by drawing directly onto a CAPI (Canvas API) provided by Skiko, a graphics library that abstracts over Skia (for Android and desktop) and CoreGraphics (for iOS). This allows for consistent rendering across platforms.
Live Demos and iOS Integration
The session featured live demonstrations showcasing the capabilities of Compose Multiplatform on iOS. Sebastian Aigner walked through a sample application, highlighting how standard Jetpack Compose code for UI elements, state management (using remember), layouts (like Column), and modifiers can be shared and run on iOS simulators and devices. He demonstrated features like text input, button interactions, and even integration with iOS-specific functionalities like the share sheet, emphasizing the goal of seamless interoperability.
The speakers also discussed the importance of providing solid accessibility integrations and ensuring smooth performance, even on high-refresh-rate displays, which is an ongoing area of focus for the Kotlin/Native and Compose Multiplatform teams. Interoperability with existing iOS UI code (SwiftUI and UIKit) was also presented as a key feature, allowing for gradual adoption. Developers can embed Compose Multiplatform views within existing SwiftUI applications or, conversely, embed native iOS views within a Compose Multiplatform UI. This flexibility is crucial for teams looking to integrate Compose into their established projects incrementally.
Getting Started and Future Outlook
Sebastian and Nikita provided clear guidance on how developers can start experimenting with Compose Multiplatform for iOS. They pointed to project templates, sample applications available on the Compose Multiplatform GitHub repository (including to-do list apps and code viewers), and updated KMP production samples that now include branches with Compose-based UI implementations. The new memory manager in Kotlin/Native was also mentioned as a significant improvement, simplifying multi-threaded programming for all Kotlin targets, including iOS.
While acknowledging that the iOS target was in Alpha and some areas were still works in progress, the overall message was one of excitement and a call to action for the community. They encouraged developers to explore the technology, provide feedback, and contribute to its evolution. The vision is a future where developers can agree on a delightful way to write UIs for all their target platforms using Kotlin.
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[KotlinConf2023] KotlinConf’23 Keynote: The Future of Kotlin is Bright and Multiplatform
KotlinConf’23 kicked off with an energizing keynote, marking a much-anticipated return to an in-person format in Amsterdam. Hosted by Hadi Hariri of JetBrains, the session brought together key figures from both JetBrains and Google, including Roman Elizarov, Svetlana Isakova, Egor Tolstoy, and Grace Kloba (VP Engineering for Android Developer Experience at Google), to share exciting updates and future directions for the Kotlin language and its ecosystem. The conference also featured a global reach with KotlinConf Global events in 41 countries. The main announcements from the keynote are also available in a blog post on the Kotlin blog.
The keynote celebrated Kotlin’s impressive growth, with statistics highlighting its widespread adoption, particularly in Android development where it’s the most popular language, used in over 95% of the top 1000 Android apps. A major focus was the upcoming Kotlin 2.0, centered around the new K2 compiler, which promises significant performance improvements, stability, and a foundation for future language evolution. The K2 compiler is nearing completion and is set to be released as Kotlin 2.0. The IntelliJ IDEA plugin will also adopt the K2 frontend, aligning with IntelliJ releases.
The Evolution of Kotlin: K2 Compiler and Language Features
The K2 compiler was a central theme of the keynote, marking a major milestone for Kotlin. This new compiler front-end, which also powers the IDE, is designed to be faster, more stable, and enable the development of new language features and tooling capabilities more rapidly. Kotlin 2.0, built on K2, is expected to bring these benefits to all Kotlin developers, enhancing both compiler performance and IDE responsiveness.
Looking beyond Kotlin 2.0, the speakers provided a glimpse into potential future language features that are under consideration. These included:
* Static Extensions: Allowing extension functions to be resolved statically, potentially improving performance and clarity.
* Collection Literals: Introducing a more concise syntax for creating collections, like using square brackets for lists, with efficient implementations.
* Name-Based Destructuring: Offering a more flexible way to destructure objects based on property names rather than just position.
* Context Receivers: A powerful feature for providing contextual information to functions in a more implicit and structured manner. This feature, however, is being approached carefully to ensure it aligns well with Kotlin’s principles.
* Explicit Fields: Providing more control over backing fields for properties.
The team emphasized a careful approach to evolving the language, ensuring new features are well-designed and maintainable. Compiler plugins were also highlighted as an avenue for extending Kotlin’s capabilities.
Kotlin in the Ecosystem: Google’s Investment and Multiplatform Growth
Grace Kloba from Google took the stage to reiterate Google’s strong commitment to Kotlin. She shared insights into Google’s investments in the Kotlin ecosystem, including the development of Kotlin Symbol Processing (KSP) and the continued focus on making Kotlin the default choice for Android development. Google officially supported Kotlin for Android development by early 2017. The Kotlin DSL is now the default for Gradle build scripts in Android Studio, enhancing developer experience with features like semantic highlighting and code completion. Google also actively contributes to the Kotlin Foundation and encourages the community to participate through programs like the Kotlin Foundation Grants Program, which focuses on supporting multiplatform libraries and frameworks.
Kotlin Multiplatform (KMP) was another major highlight, showcasing its growing maturity and adoption. The vision for KMP is to allow developers to share code across various platforms—Android, iOS, desktop, web, and server-side—while retaining the ability to write platform-specific code when needed. The keynote celebrated the increasing number of multiplatform libraries and tools, including KMM Bridge, that simplify KMP development. The future of KMP looks bright, with efforts to further improve the developer experience and expand its capabilities.
Compose Multiplatform and Emerging Technologies
The keynote also showcased the advancements in Compose Multiplatform, JetBrains’ declarative UI framework for building cross-platform user interfaces. A significant announcement was the alpha release of Compose Multiplatform for iOS, enabling developers to write their UI once in Kotlin and deploy it on both Android and iOS, and even desktop and web. This opens up new possibilities for code sharing and faster development cycles for mobile applications.
Finally, the team touched upon Kotlin’s expansion into emerging technologies like WebAssembly (Wasm). JetBrains is developing a new compiler backend for Kotlin targeting WebAssembly with its garbage collection proposal, aiming for high-performance Kotlin code in the browser. Experiments with running Compose applications in the browser using WebAssembly were also mentioned, hinting at a future where Kotlin could offer a unified development experience across an even wider range of platforms. The keynote concluded with an invitation for the community to dive deeper into these topics during the conference and to continue contributing to Kotlin’s vibrant ecosystem.
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[KotlinConf2019] Exploring the Power of Kotlin/JS
Sebastian Aigner, a developer advocate at JetBrains, captivated KotlinConf2019 with his deep dive into Kotlin/JS, the JavaScript target for Kotlin. With a passion for web development, Sebastian showcased how recent advancements make Kotlin/JS a compelling choice for building web applications. From streamlined tooling to seamless JavaScript interoperability, he outlined the current state and future potential of Kotlin/JS, inspiring both newcomers and seasoned developers to leverage Kotlin’s paradigms in the browser.
Simplifying Development with the New Gradle Plugin
Kotlin/JS has evolved significantly, with the new Kotlin/JS Gradle plugin emerging as the cornerstone for browser and Node.js development. Sebastian explained that this plugin unifies previously fragmented approaches, replacing deprecated plugins like kotlin2js and kotlin-frontend. Its uniform Gradle DSL simplifies project setup, offering sensible defaults for Webpack bundling without requiring extensive configuration. For developers transitioning to multi-platform projects, the plugin’s compatibility with the Kotlin multi-platform DSL minimizes changes, enabling seamless integration of additional targets. By automating JavaScript environment setup, including yarn and package.json, the plugin empowers Kotlin developers to focus on coding rather than managing complex JavaScript tooling.
Mastering Dependency Management with npm
The JavaScript ecosystem, with over a million npm packages, offers unparalleled flexibility, and Kotlin/JS integrates effortlessly with this vast library. Sebastian highlighted how the Gradle plugin manages npm dependencies directly, automatically updating package.json when dependencies like React or styled-components are added. This eliminates the need for separate JavaScript environment setup, saving time, especially on non-standard platforms like Windows. Developers can import Kotlin libraries (e.g., coroutines, serialization) alongside JavaScript packages, with Gradle handling the JavaScript-specific versions. This unified approach bridges the gap between Kotlin’s structured ecosystem and JavaScript’s dynamic world, making dependency management intuitive even for those new to JavaScript.
Bridging Kotlin and TypeScript with Dukat
Interoperating with JavaScript’s dynamic typing can be challenging, but Sebastian introduced Dukat, an experimental tool that converts TypeScript declaration files into Kotlin external declarations. By leveraging TypeScript’s de facto standard for type definitions, Dukat enables type-safe access to npm packages, such as left-pad or react-minimal-pie-chart. While manual external declarations require tedious annotation, Dukat automates this process, generating headers for packages with TypeScript support or community-contributed definitions. Sebastian encouraged early adoption to provide feedback, noting that Dukat already powers browser and Node.js API wrappers. This tool promises to simplify integration with JavaScript libraries, reducing the friction of crossing the static-dynamic typing divide.
Enhancing Testing and Debugging with Source Maps
Testing and debugging are critical for robust applications, and Kotlin/JS delivers with integrated tools. Sebastian demonstrated how the Gradle plugin supports platform-specific test runners like Karma, allowing tests to run across browsers (e.g., Firefox, headless Chrome). Source maps, automatically generated since Kotlin 1.3.60, provide detailed stack traces for Node.js and interactive debugging in browser DevTools. Developers can set breakpoints in Kotlin code, inspect variables, and trace errors directly in Chrome’s console, as shown in Sebastian’s pong game demo. Gradle test reports further enhance diagnostics, offering HTML-based insights into test failures, making Kotlin/JS development as robust as its JVM counterpart.
Optimizing with the IR Backend
The upcoming Intermediate Representation (IR) backend marks a significant leap for Kotlin/JS. Sebastian outlined its benefits, including aggressive code size optimizations through dead code elimination. Unlike the current backend, which may ship the entire standard library, the IR backend, combined with Google Closure Compiler, reduces zipped file sizes dramatically—down to 30 KB from 3.9 MB in some cases. Faster compilation speeds, especially for incremental builds, enhance developer productivity, particularly in continuous build scenarios with Webpack’s dev server. The IR backend also supports platform-agnostic compiler plugins, simplifying multi-platform development. Sebastian noted that pre-alpha IR support in Kotlin 1.3.70 requires manual exports due to its closed-world assumption, urging developers to explore early releases.
Looking Ahead: WebAssembly and Framework Support
Sebastian concluded with a glimpse into Kotlin/JS’s future, highlighting potential support for ECMAScript 6 modules and frameworks like Angular and Vue.js. While JetBrains provides React wrappers, extending first-class support to other frameworks requires addressing their unique tooling and compilers. The IR backend also opens doors to WebAssembly, enabling Kotlin to target browsers more efficiently. Though no timelines were promised, these explorations reflect JetBrains’ commitment to aligning Kotlin/JS with modern web trends. Sebastian’s call to action—trying the Code Quiz app at the Kotlin booth and contributing to Dukat—emphasized community involvement in shaping Kotlin/JS’s evolution.
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[KotlinConf2019] Kotless: A Kotlin-Native Approach to Serverless with Vladislav Tankov
Serverless computing has revolutionized how applications are deployed and scaled, but it often comes with its own set of complexities, including managing deployment DSLs like Terraform or CloudFormation. Vladislav Tankov, then a Software Developer at JetBrains, introduced Kotless at KotlinConf 2019 as a Kotlin Serverless Framework designed to simplify this landscape. Kotless aims to eliminate the need for external deployment DSLs by allowing developers to define serverless applications—including REST APIs and event handling—directly within their Kotlin code using familiar annotations. The project can be found on GitHub at github.com/JetBrains/kotless.
Vladislav’s presentation provided an overview of the Kotless Client API, demonstrated its use with a simple example, and delved into the architecture and design concepts behind its code-to-deployment pipeline. The core promise of Kotless is to make serverless computations easily understandable for anyone familiar with event-based architectures, particularly those comfortable with JAX-RS-like annotations.
Simplifying Serverless Deployment with Kotlin Annotations
The primary innovation of Kotless, as highlighted by Vladislav Tankov, is its ability to interpret Kotlin code and annotations to automatically generate the necessary deployment configurations for cloud providers like AWS (initially). Instead of writing separate configuration files in YAML or other DSLs, developers can define their serverless functions, API gateways, permissions, and scheduled events using Kotlin annotations directly on their functions and classes.
For example, creating a REST API endpoint could be as simple as annotating a Kotlin function with @Get("/mypath"). Kotless then parses these annotations during the build process and generates the required infrastructure definitions, deploys the lambdas, and configures the API Gateway. This approach significantly reduces boilerplate and the cognitive load associated with learning and maintaining separate infrastructure-as-code tools. Vladislav emphasized that a developer only needs familiarity with these annotations to create and deploy a serverless REST API application.
Architecture and Code-to-Deployment Pipeline
Vladislav Tankov provided insights into the inner workings of Kotless, explaining its architecture and the pipeline that transforms Kotlin code into a deployed serverless application. This process generally involves:
1. Annotation Processing: During compilation, Kotless processes the special annotations in the Kotlin code to understand the desired serverless architecture (e.g., API routes, event triggers, scheduled tasks).
2. Terraform Generation (Initially): Kotless then generates the necessary infrastructure-as-code configurations (initially using Terraform as a backend for AWS) based on these processed annotations. This includes defining Lambda functions, API Gateway resources, IAM roles, and event source mappings.
3. Deployment: Kotless handles the deployment of these generated configurations and the application code to the target cloud provider.
He also touched upon optimizations built into Kotless, such as “outer warming” of lambdas to reduce cold starts and optimizing lambdas by size. This focus on performance and ease of use is central to Kotless’s philosophy. The framework aims to abstract away the underlying complexities of serverless platforms, allowing developers to concentrate on their application logic.
Future Directions and Multiplatform Aspirations
Looking ahead, Vladislav Tankov discussed the future roadmap for Kotless, including ambitious plans for supporting Kotlin Multiplatform Projects (MPP). This would allow developers to choose different runtimes for their lambdas—JVM, JavaScript, or even Kotlin/Native—depending on the task and performance requirements. Supporting JavaScript lambdas, for example, could open up compatibility with platforms like Google Cloud Platform more broadly, which at the time had better support for JavaScript runtimes than JVM for serverless functions.
Other planned enhancements included extended event handling for custom events on AWS and other platforms, and continued work on performance optimizations. The vision for Kotless was to provide a comprehensive and flexible serverless solution for Kotlin developers, empowering them to build efficient and scalable cloud-native applications with minimal friction. Vladislav encouraged attendees to try Kotless and contribute to its development, positioning it as a community-driven effort to improve the Kotlin serverless experience.
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[KotlinConf2019] Kotlin Multiplatform Programming: Present and Future with Dmitry Savvinov and Liliia Abdulina
Kotlin Multiplatform Programming (MPP) has been a significant focus for JetBrains, aiming to extend Kotlin’s reach beyond traditional JVM and Android development. At KotlinConf 2019, Dmitry Savvinov and Liliia Abdulina, both from the Kotlin team at JetBrains, delivered an insightful overview of MPP’s capabilities in version 1.3.X and offered a glimpse into its future direction. Dmitry Savvinov, a key contributor to Kotlin Contracts and heavily involved in MPP, brought his compiler expertise to the discussion. The official Kotlin language website, the central hub for MPP information, is kotlinlang.org.
Their talk was structured to cover the fundamentals of multiplatform projects, illustrate these basics with examples, provide guidelines for designing first multiplatform projects, and showcase a production-like application to demonstrate design principles in action. This comprehensive approach aimed to equip developers with the knowledge needed to start leveraging MPP effectively.
Core Concepts of Kotlin Multiplatform
Dmitry Savvinov and Liliia Abdulina began by explaining the core building blocks of Kotlin Multiplatform projects. These foundational concepts are crucial for understanding how code can be shared and specialized across different platforms:
* Source Sets: The fundamental unit of code organization in MPP. A project is typically structured with a commonMain source set containing platform-agnostic Kotlin code. Platform-specific source sets (e.g., jvmMain, jsMain, iosMain) contain code tailored for each target and can depend on commonMain.
* Targets: These define the platforms the project will compile for, such as JVM, Android, JavaScript, iOS (Native), Linux, Windows, and macOS. Each target has its own compilations.
* Compilations: A compilation process for a specific target that produces the appropriate artifacts (e.g., JVM bytecode, JavaScript files, native executables).
* expect and actual Declarations: This powerful mechanism allows common code in commonMain to declare an expect class, function, or property. Platform-specific source sets must then provide an actual implementation for that declaration, bridging the gap between shared logic and platform-specific APIs. For example, a common module might expect a function to generate a UUID, and the JVM and Native modules would provide actual implementations using their respective platform libraries.
These concepts enable developers to write shared business logic, data models, and algorithms once in commonMain and then reuse them across multiple platforms, significantly reducing code duplication and improving consistency.
Designing and Implementing Multiplatform Projects
Beyond the basic syntax, Dmitry and Liliia provided guidance on how to approach the design of a multiplatform project. This involved discussing strategies for identifying what code can and should be shared, how to structure modules for optimal maintainability, and best practices for using expect/actual effectively.
They used toy examples to illustrate these basics in a clear and understandable manner, helping attendees grasp how these pieces fit together in a real project. The presentation then progressed to showcase a “more or less production-like application”. This larger example would have served to demonstrate how the design principles discussed could be applied to build a substantial, real-world multiplatform application, highlighting how to manage dependencies, handle platform-specific interactions, and structure a scalable MPP architecture. The focus was on providing practical insights that developers could apply to their own projects, whether starting from scratch or integrating MPP into existing applications.
The Trajectory of Kotlin Multiplatform: Beyond 1.3.X
While detailing the state of MPP in Kotlin 1.3.X, Dmitry Savvinov and Liliia Abdulina also looked towards its future development. At KotlinConf 2019, MPP was still evolving, with ongoing improvements to tooling, library support, and the overall developer experience. Their talk touched upon the roadmap for MPP, including planned enhancements to areas like Kotlin/Native (for performance and interoperability), library ecosystem growth, and further refinements to the build system and IDE support within IntelliJ IDEA and Android Studio.
The vision presented was one of Kotlin as a truly universal language, enabling developers to target a wide array of platforms with a unified codebase and skillset. The commitment from JetBrains to invest heavily in MPP was clear, with the aim of making it a robust and production-ready solution for cross-platform development. The session would have encouraged developers to explore MPP, provide feedback, and contribute to its growing ecosystem, reinforcing the community-driven aspect of Kotlin’s development.
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[KotlinConf2019] Ktor for Mobile Developers: Conquering the Server with Dan Kim
For many mobile developers, the thought of venturing into server-side development can be daunting, often perceived as a realm of unfamiliar languages, complex frameworks, and different programming paradigms. Dan Kim, an experienced developer, aimed to demystify this process at KotlinConf 2019 with his talk, “Ktor for Mobile Developers: Fear the server no more!”. He showcased Ktor, a Kotlin-based framework for building asynchronous servers and clients, as an accessible and powerful tool for mobile developers looking to create backend components for their applications. The official website for Ktor is ktor.io.
Dan Kim’s session was designed to demonstrate how existing Kotlin knowledge could be leveraged to easily build server-side applications with Ktor. He promised a practical, real-world example, walking attendees through everything needed to get a server up and running: authentication, data retrieval, data posting, and deployment, ultimately aiming to give mobile developers the confidence to build their own backend services.
Introducing Ktor: Simplicity and Power in Kotlin
Ktor is a framework built by JetBrains, designed from the ground up with Kotlin and coroutines in mind, making it inherently asynchronous and well-suited for building scalable network applications. Dan Kim introduced Ktor’s core concepts, such as its flexible pipeline architecture, routing capabilities, and features for handling HTTP requests and responses. A key appeal of Ktor for mobile developers is that it allows them to stay within the Kotlin ecosystem, using a language and paradigms they are already familiar with from Android development.
The presentation would have highlighted Ktor’s ease of use and minimal boilerplate. Unlike some larger, more opinionated server-side frameworks, Ktor offers a more unopinionated and lightweight approach, allowing developers to choose and configure only the features they need. This can include functionalities like authentication, content negotiation (e.g., for JSON or XML), templating engines, and session management, all installable as “features” or plugins within a Ktor application.
Building a Real-World Server-Side Component
The core of Dan Kim’s talk was a hands-on demonstration of building a server-side component. He aimed to build a RESTful API and a web application, complete with authentication, and deploy it to Google Cloud, all within an impressively small amount of code (around 350 lines, as he mentioned). This practical example would have covered essential aspects of backend development:
* Routing: Defining endpoints to handle different HTTP methods (GET, POST, etc.) and URL paths.
* Request Handling: Processing incoming requests, extracting parameters, and validating data.
* Authentication: Implementing mechanisms to secure endpoints and manage user identity, possibly integrating with external services.
* Data Interaction: Showing how to get data from and post data to other services or a database (though the specifics of database interaction might vary).
* Deployment: Walking through the process of deploying the Ktor application to a cloud platform like Google Cloud, making the backend accessible to mobile clients.
By tackling these common server-side tasks using Ktor and Kotlin, Dan aimed to alleviate the fears mobile developers might have about backend development and demonstrate that they already possess many of the necessary skills.
Empowering Mobile Developers to Go Full-Stack
The overarching message of Dan Kim’s presentation was one of empowerment. He sought to show that with Ktor, mobile developers no longer need to “fear the server”. The framework provides a gentle learning curve and a productive environment for building robust and efficient backend services. This capability is increasingly valuable as mobile applications become more sophisticated and often require custom backend logic to support their features.
Dan Kim’s practical demonstration, from basic Ktor setup to cloud deployment, was intended to give attendees a clear understanding of how to connect their own server-side components to virtually any API. By simplifying the backend development process, Ktor enables mobile developers to potentially take on more full-stack responsibilities, leading to greater control over their application’s entire architecture and a faster development cycle for new features. He hoped his session would provide the confidence needed for mobile developers to start building their own server-side solutions with Kotlin and Ktor.
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[KotlinConf2019] KotlinConf 2019 Keynote: People, Ideas, and Software in the Kotlin Ecosystem with Andrey Breslav
The opening keynote of KotlinConf 2019, delivered by Andrey Breslav, the then Lead Language Designer for Kotlin at JetBrains, set an inspiring tone for the conference. Addressing a packed room of 1,700 attendees, with many more watching online, Andrey articulated a vision of Kotlin that extends beyond mere syntax and features, emphasizing it as an ecosystem built upon three pillars: people, ideas, and software. His presentation underscored the collaborative spirit that fuels Kotlin’s growth and the continuous feedback loop that shapes its evolution. The official Kotlin language website, central to this ecosystem, is kotlinlang.org.
Andrey Breslav began by reflecting on Kotlin’s journey and its burgeoning community. He highlighted that the success and adoption of Kotlin are deeply intertwined with the people who use it, contribute to it, and advocate for it. This “people-first” perspective was a recurring theme, as he stressed that Kotlin is designed to bring developers together, fostering a common way of working and shared values. The vibrant interactions at KotlinConf itself, with developers from around the world sharing experiences and knowledge, served as a living testament to this community-centric approach.
The Power of Ideas and Continuous Improvement
A core tenet of Kotlin’s development philosophy, as outlined by Andrey Breslav, is the importance of ideas and the relentless pursuit of improvement. He emphasized that the Kotlin team at JetBrains actively seeks and values feedback from the developer community. This feedback loop is critical, whether it comes through direct communication, bug reports, feature requests, or even passively through anonymized usage statistics collected by JetBrains’ IDEs. These statistics, he explained, help the team understand how Kotlin is used in real-world scenarios, identify pain points (like slow code completion in specific environments), and prioritize areas for enhancement.
This data-informed approach allows the Kotlin team to make more effective decisions about the language’s future direction. Andrey encouraged attendees to participate in this feedback process, assuring them that their input, no matter how small, contributes to making Kotlin better for everyone. He cited examples where community feedback directly influenced language features and tooling improvements, reinforcing the idea that Kotlin’s evolution is a collaborative effort. This commitment to listening and adapting ensures that Kotlin remains a pragmatic and powerful tool that addresses the real-world needs of developers.
Software as a Collaborative Endeavor
The third pillar, software, encompasses not only the Kotlin language itself but also the rich ecosystem of libraries, tools, and frameworks that surround it. Andrey Breslav highlighted the importance of this broader ecosystem in making Kotlin a productive and enjoyable language to work with. He acknowledged the contributions of the community in building these resources, from open-source libraries to educational materials and tutorials.
Furthermore, Andrey spoke about JetBrains’ ongoing efforts to enhance the Kotlin tooling, including the compiler and IDE support, to improve performance, stability, and developer experience. He touched upon initiatives aimed at making Kotlin more versatile, enabling its use across various platforms—JVM, Android, JavaScript, Native—and for different types of applications, from server-side systems to mobile apps and web frontends. The keynote celebrated the milestones achieved, such as the growing adoption of Kotlin Multiplatform, while also looking ahead to future challenges and opportunities. Andrey concluded by reiterating that every form of participation, from writing code and tutorials to sharing experiences and even simple social media interactions, adds value to the Kotlin community and contributes to its collective success.
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[KotlinConf2019] A Vibrant Gathering of the Global Kotlin Community
KotlinConf 2019, held in Copenhagen, Denmark, from December 4-6, marked a significant moment for the Kotlin ecosystem, bringing together a passionate global community of developers, enthusiasts, and industry leaders. With over 1,600 attendees on-site and many thousands more joining via live stream, the conference was a testament to Kotlin’s burgeoning popularity and its expanding footprint across various domains of software development. The event, meticulously organized by JetBrains, the creators of Kotlin, served as a vibrant hub for knowledge sharing, networking, and celebrating the language’s latest advancements and future directions. The official Kotlin language website, a key resource for developers, is kotlinlang.org.
The atmosphere, as captured in highlight reels and attendee testimonials, was electric, filled with excitement and a shared enthusiasm for the language’s capabilities. Attendees praised the depth of technical talks, the relatability of the content to their daily work, and the motivating nature of keynote presentations that often held an element of suspense regarding new feature announcements. More than just a series of lectures, KotlinConf fostered a strong sense of community, a recurring theme in participants’ feedback, who often cited the community itself as one of the best parts of their Kotlin experience. This collective energy underscored Kotlin’s journey from a promising JVM language to a versatile tool impacting Android development, backend systems, web frontends, and multiplatform projects.
A Hub for Learning and Innovation
KotlinConf 2019 provided a rich learning environment, offering a diverse range of sessions that catered to various skill levels and interests. From in-depth explorations of Kotlin’s newest features to practical workshops and discussions on best practices, the conference was a platform for developers to enhance their skills and gain new perspectives. The content was designed to be both insightful and applicable, with many attendees noting the direct relevance of the talks to their ongoing projects and challenges. This focus on practical application, combined with a forward-looking vision for the language, made the event invaluable for professionals seeking to stay at the forefront of software development.
The conference also served as a crucial touchpoint for JetBrains to engage with the Kotlin community, gather feedback, and share their roadmap for the language’s evolution. This open dialogue is a hallmark of Kotlin’s development philosophy, ensuring that the language continues to meet the needs of its users and adapt to the ever-changing technological landscape. The excitement around new announcements and the opportunity to interact directly with the minds behind Kotlin added an extra layer of dynamism to the event, reinforcing its status as a premier conference for anyone invested in the Kotlin ecosystem. The success of such an event relies heavily on the engagement of its community, from the speakers sharing their expertise to the attendees bringing their curiosity and passion, all contributing to what many described as an “industrial revolution” in software development.
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[KotlinConf2018] Mastering Concurrency: Roman Elizarov’s Practical Guide to Kotlin Coroutines
Lecturer
Roman Elizarov is a seasoned software developer at JetBrains, with over 17 years of experience in high-performance trading software at Devexperts. An expert in Java and JVM, he teaches concurrent programming at St. Petersburg ITMO and serves as Chief Judge for the Northeastern European Regional Programming Contest. Relevant links: JetBrains Blog (publications); LinkedIn Profile (professional page).
Abstract
This article follows Roman Elizarov’s practical application of Kotlin coroutines to address concurrency challenges. Set in the context of large-scale systems, it examines methodologies for state confinement and communication via channels. The analysis highlights coroutines’ innovations in eliminating shared mutable state, with implications for robust, scalable architectures.
Introduction and Context
Roman Elizarov engaged KotlinConf 2018 attendees with a deep dive into coroutines, building on his prior introductory talk. With a vision for a unified language across distributed systems, Elizarov showcased coroutines as a solution to concurrency without shared mutable state. His examples addressed real-life coordination, set against his experience with high-throughput trading systems processing millions of events per second.
Methodological Approaches to Concurrency
Elizarov demonstrated coroutines confining state to single coroutines, communicating via channels. Each coroutine handles a specific task, receiving input and sending output through channels, avoiding locks. For UI integration, coroutines on the main thread directly update views or report via channels for decoupled architectures. Builders like launch and async orchestrate tasks, while suspend functions enable non-blocking code.
Analysis of Innovations and Features
Coroutines innovate by simplifying async programming. Channels provide fan-out communication, unlike threads’ shared state. Compared to Java’s CompletableFuture, coroutines preserve sequential code structure. Limitations include a learning curve for channel patterns and ensuring proper context management.
Implications and Consequences
Elizarov’s approach implies cleaner, safer concurrency models, reducing bugs in complex systems. It suits UI-driven apps and distributed systems, enhancing scalability. The consequence is a shift toward channel-based designs, though teams must master coroutine semantics.
Conclusion
Elizarov’s practical guide positions coroutines as a cornerstone for modern concurrency, offering a robust alternative to traditional threading models.
Links
- Lecture video: https://www.youtube.com/watch?v=a3agLJQ6vt8
- Lecturer’s X/Twitter: @relizarov
- Lecturer’s LinkedIn: Roman Elizarov
- Organization’s X/Twitter: @JetBrains
- Organization’s LinkedIn: JetBrains