SDK Engineer

About the role

You’ll design and maintain developer-facing libraries like monimejs. The work is about API ergonomics, type safety, and making other developers’ lives easier. You’ll spend as much time thinking about how something should be called as how it should be implemented.

What you’ll do

• Design TypeScript APIs that are intuitive and hard to misuse
• Maintain SDKs with full type coverage — success cases and error cases
• Write retry logic, idempotency handling, and cancellation support
• Keep dependencies at zero (or as close to it as possible)
• Write documentation that starts with “here’s how to do the thing you came here for”

What we’re looking for

• Deep TypeScript knowledge — generics, conditional types, discriminated unions
• Experience building or maintaining a library that other developers use
• You think about error handling before the happy path
• You’ve debugged a transitive dependency issue and vowed never again
• You can explain a complex API in a README that fits on one screen

Nice to have

• Published a package on npm that you’re not embarrassed by
• Experience with payment or fintech APIs
• Familiarity with the Fetch API’s edge cases and streaming behavior