KPPAY

I brought the user, merchant, and admin apps into one monorepo and built the developer portal and SDKs that make the payment gateway easier to use.

Software engineer

The problem

Several apps needed the same sign-in logic, payment types, and UI components. Keeping separate copies made changes take longer and easier to get wrong.

Monorepo architecture

I moved shared sign-in, dashboard, finance, and UI code into packages used across the apps. I also added generated GraphQL types and checks that catch dependency mistakes before deployment.

Merchant integration

I built the merchant developer area around application setup, test and live keys, key rotation, and API access. I fixed key creation for existing APIs and brought payment-link creation into one flow.

TypeScript and Rust SDKs

I wrote TypeScript and Rust clients for the Gateway REST API. They give developers typed ways to create checkouts, collect payments, inspect payment status, and make transfers. They also make retry keys, timeouts, and API errors explicit, so an accepted request is not confused with a completed payment.

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