New hire reporting
Built Salsa's new hire reporting product end to end: an event-driven compliance pipeline that reports new hires to US state agencies, launched from 5 pilot states to all 50 for both employees and contractors.
Salsa · 2026
Marcos Nikel
Software engineer · Sao Paulo, Brazil
Backend-focused engineer with 4+ years building fintech systems: payroll and tax compliance infrastructure at Salsa, high-traffic services at Mercado Libre, and document automation for European banks at NowCM. Comfortable across the stack with TypeScript and React when needed.
Selected work
Async tax file generation
Redesigned quarterly tax file generation from a synchronous, memory-bound process into a chunked async pipeline with retries and dead-lettering, validated against the previous output before cutover.
Salsa · 2026
Partner audit log
Led the delivery of a partner-facing audit log: multi-tenant GraphQL API, React UI, and public documentation, rolled out from the first partner to all of them.
Salsa · 2026
High-traffic Go services
Refactored a Go service handling 500K requests per minute and improved resilience across critical paths with retries, circuit breakers, rate limiting, and caching.
Mercado Libre · 2024 to 2026
About
I got into computers early, spent my childhood gaming, and wrote my first code at 10 while setting up a game server. I started college in nutrition, switched to computer science a year later, and turned the hobby into a career.
I like being close to the product, collaborating with the people around me, and working on systems where correctness matters. Outside of work I lift and run, and I am currently training for my first marathon.
Contact
The fastest way to reach me is email. You can also send a message directly from here and I will get back to you.