Posts Tagged ‘HarunWangereka’
[KotlinConf2023] Transforming Farmers’ Lives in Kenya: Apollo Agriculture’s Android Apps with Harun Wangereka
Harun Wangereka, a Software Engineer at Apollo Agriculture and a Google Developer Expert for Android, delivered an inspiring presentation at KotlinConf’23 about how his company is leveraging Android technology to change the lives of farmers in Kenya. His talk detailed Apollo Agriculture’s two core Android applications, built entirely in Kotlin, which are offline-first and utilize server-driven UI (SDUI) with Jetpack Compose to cater to the unique challenges of their user base. Harun is also active in Droidcon Kenya.
Apollo Agriculture’s mission is to empower small-scale farmers by bundling financing, high-quality farm inputs, agronomic advice, insurance, and market access. Their tech-based approach uses satellite data and machine learning for credit decisions and automated operations to maintain low costs and scalability. The customer journey involves signup via agents or SMS/USSD, kyc data collection (including GPS farm outlines), automated credit decisions (often within minutes), input pickup from agro-dealers, digital advice via voice trainings, and loan repayment post-harvest.
Addressing Unique Challenges in the Kenyan Context
Harun highlighted several critical challenges that shaped their app development strategy:
* Low-Memory Devices: Many agents and farmers use entry-level Android devices with limited RAM and storage. The apps need to be lightweight and performant.
* Low/Intermittent Internet Bandwidth: Internet connectivity can be unreliable and expensive. An offline-first approach is crucial, allowing agents to perform tasks without constant internet access and sync data later.
* Diverse User Needs and Rapid Iteration: The agricultural domain requires frequent updates to forms, workflows, and information provided to farmers and agents. A flexible UI system that can be updated without frequent app releases is essential.
These challenges led Apollo Agriculture to adopt a server-driven UI (SDUI) approach. Initially implemented with Anko (a deprecated Kotlin library for Android UI), they later rewrote this system entirely using Jetpack Compose.
Server-Driven UI with Jetpack Compose
The core of their SDUI system relies on JSON responses from the server that define the UI components, their properties, validations, and conditional logic.
Key aspects of their implementation include:
* Task-Based Structure: The app presents tasks to agents (e.g., onboarding a farmer, collecting survey data). Each task is represented by a JSON schema from the server.
* Dynamic Form Rendering: The JSON schema defines various UI elements like text inputs, number inputs, date pickers, location pickers (with map integration for capturing farm boundaries), image inputs (with compression), and more. These are dynamically rendered using Jetpack Compose.
* Stateful Composable Components: Harun detailed their approach to building stateful UI components in Compose. Each question or input field manages its own state (value, errors, visibility) using remember and mutableStateOf. Validation logic (e.g., required fields, min/max length) is also defined in the JSON and applied dynamically.
* Triggers and Conditionals: The JSON schema supports triggers (e.g., “on save”) and complex conditional logic using an internal tool called “Choice Expressions” and an implementation of JSON Schema. This allows UI elements or entire sections to be shown/hidden or enabled/disabled based on user input or other conditions, enabling dynamic and context-aware forms.
* Offline First: Task schemas and user data are stored locally, allowing full offline functionality. Data is synced with the server when connectivity is available.
* Testing: They extensively test their dynamic UI components and state logic in isolation, verifying state changes, validation behavior, and conditional rendering.
Harun shared examples of the JSON structure for defining UI elements, properties (like labels, hints, input types), validators, and conditional expressions. He walked through how a simple text input composable would manage its state, handle user input, and apply validation rules based on the server-provided schema.
Learnings and Future Considerations
The journey involved migrating from Anko to Jetpack Compose for their SDUI renderer, which Compose’s reactive DSL made more manageable and maintainable. They found Compose to be well-suited for building dynamic, stateful UIs.
Challenges encountered included handling keyboard interactions smoothly with scrolling content and managing the complexity of deeply nested conditional UIs.
When asked about open-sourcing their powerful form-rendering engine, Harun mentioned it’s a possibility they are considering, as the core logic is already modularized, and community input could be valuable. He also noted that while some pricing information is dynamic (e.g., based on farm size), they try to standardize core package prices to avoid confusion for farmers.
Harun Wangereka’s talk provided a compelling case study of how Kotlin and Jetpack Compose can be used to build sophisticated, resilient, and impactful Android applications that address real-world challenges in demanding environments.