Project
Klasha Payment SDK
Production Android library built as a Kotlin wrapper over Klasha's payment API, with Java interoperability, asynchronous interfaces, retry handling, and sandbox support.
Results and deliverables
- Delivered a production Android SDK
- Supported Kotlin and Java consumers
- Exposed payment integration through a smaller mobile-facing API
Overview
A contract engagement with Klasha — a fintech startup enabling cross-border payments in Africa. The deliverable was an Android SDK that would allow other Android developers to integrate Klasha's payment API with minimal boilerplate.
Technical Details
Built as a Kotlin library with Java interoperability, the SDK wraps Klasha's REST payment API and provides:
- A clean, idiomatic Kotlin API for payment initiation
- Callback and coroutine-based async patterns
- Built-in retry logic with configurable backoff
- Sandbox mode for development and testing
- A compact API surface designed for use from both Kotlin and Java applications
Key Learnings
This was my first production SDK — the experience taught me a lot about API design for library consumers. The constraint of not knowing how your code will be used forces you to think carefully about error handling, nullability contracts, and backwards compatibility from day one.