Klasha Payment SDK

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
• Comprehensive unit tests (JUnit + Mockito) and integration tests

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.