The problem
eSewa — Nepal’s leading digital wallet — wanted event ticketing (concerts, seminars, game shows, parties) inside its app. But you don’t ship features into someone else’s flagship fintech app; you ship a module they can trust: isolated, secure, performant, and unable to destabilize their host app.
My role
Led development and integration of the SDK end-to-end: architecture, implementation, documentation, and technical support through eSewa’s deployment.
Architecture decisions
- SDK-first design — strict API surface, no leaked internals, and dependency isolation so the module couldn’t collide with the host app’s libraries or DI graph.
- MVVM inside the boundary — the SDK carried its own presentation architecture (Kotlin, coroutines, Flows) so it behaved like a well-factored app within an app.
- Integration ergonomics as a feature — robust documentation and a support channel for eSewa’s engineers, because an SDK that integrates painfully doesn’t get adopted.
The hardest problem
Operating inside another company’s security and performance envelope. Every payment interaction, memory allocation and startup cost had to be justified to a host team guarding Nepal’s most-used wallet — a different discipline from owning your own app, where you set the rules.
Outcome
The SDK shipped inside eSewa with secure, high-performance ticket purchase flows, complete documentation, and supported deployment — my code running inside the most widely used fintech app in the country.