Senior Backend Engineer, API

Polymarket is the world's largest prediction market platform, enabling individuals to express views on real-world events by trading on outcomes across politics, economics, sports, culture, and current affairs. Built as a peer-to-peer marketplace with no centralized "house," Polymarket aggregates diverse opinions into transparent, market-based probabilities. The company is growing fast, with $21B traded in 2025, and aims to become a ubiquitous beacon of truth in global media. Polymarket is seeking a Senior Backend Engineer to work on Gamma, the core backend powering Polymarket's markets platform. Gamma processes every market creation, trade, and resolution at scale, under load, with no margin for error. In this role, you will ship features with direct product impact, push the boundaries of the system, and help define ownership as the platform grows. Responsibilities include architecting and implementing Go-based services capable of sustaining high request throughput with low latency at scale, defining and enforcing engineering standards (API versioning, error handling, service health benchmarks), upholding code quality through reviews and documentation, partnering cross-functionally with product and infrastructure teams, and owning reliability by contributing to on-call rotations and driving improvements.