Senior Backend Engineer, Exchange Systems

### **About Polymarket** Polymarket is the world's largest prediction market platform. We enable 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 that reflect collective expectations about the future. We're growing fast, both in terms of volume ($21B traded in 2025) and adoption as an alternative news source. Our ambition is to become a ubiquitous beacon of truth in global media and we need your help adding fuel to the fire. ### **About the Role** Polymarket is looking for a Senior Backend Engineer to join our DeFi Trading team and own core improvements to our exchange systems. You'll work across low-latency APIs, high-throughput data streams, and settlement-aware order state and with a specific focus on evolving our CLOB engine to be faster, safer, and more concurrent as the platform scales. This role requires someone who can reason clearly about how on-chain transaction lifecycle, confirmations, reorgs, balances, approvals, and execution outcomes affect off-chain exchange state. The problems are deep, the stakes are real, and the work will be immediately visible in production. ### **What You'll Do** - **Own the CLOB engine's critical path.** Profile matching and orderbook hot paths, map settlement-sensitive state transitions, and drive improvements to latency, throughput, and async engine flow backed by benchmarks and production-grade evidence. - **Reduce lock contention without breaking correctness.** Debug concurrency issues, design safer queueing and backpressure for orderbooks, and improve the system's ability to handle materially more markets and order flow with lower tail latency. - **Build for observability and safety.** Instrument improvements with pprof, metrics, logs, and traces. Establish rollback guarantees and narrower critical paths that make production incidents easier to detect, diagnose, and resolve. - **Reason about settlement risk.** Understand how on-chain transaction effects ripple into off-chain exchange state, and design systems that handle crossed books, ghost fills, stale orders, cancel inconsistencies, and settlement edge cases correctly. - **Improve the runtime.** Reduce GC pressure, optimize CPU and memory allocation behavior, and push Go runtime performance to meet the demands of a high-throughput exchange at scale. - **Debug production incidents.** Own latency, correctness, and settlement-state incidents end-to-end, and drive follow-through that leaves the system measurably better each time. ### **What We're Looking For** - Production experience building low-latency backend systems at scale - Strong concurrency skills and a track record debugging lock contention, race conditions, and async correctness issues - Fluency in production Go and Rust - Deep observability experience: pprof, metrics, logs, and distributed traces - Experience with exchange systems that interact with EVM or blockchain settlement layers - Strong computer science fundamentals: algorithms, data structures, concurrency, and profiling - (Plus) Direct experience with matching engines or exchange infrastructure - (Plus) EVM transaction lifecycle experience: confirmations, reorgs, and how on-chain state affects off-chain systems - (Plus) Go runtime and GC tuning experience - (Plus) Experience with Redis, PostgreSQL, gRPC, and Protobuf - (Plus) Kubernetes and AWS production operations experience ### **Benefits** - Competitive salary & equity - Unlimited PTO - Full Health, Vision, & Dental coverage - 401k match - Hardware setup: new MacBook Pro, big display, & accessories