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 - Senior+ backend or systems engineer with production ownership of an exchange system — perp DEX, crypto exchange, or any high-throughput trading backend with on-chain settlement -
• Hands-on experience with matching engines, order routing, or market data infrastructure where tail latency, correctness, and rollback safety were real constraints -
• Deep Go expertise — you've tuned GC pressure, optimized hot paths, and understand the runtime internals that matter in a high-throughput exchange context -
• Strong concurrency skills with a real track record: lock contention, race conditions, async correctness, and backpressure under load - Profiling experience you've actually used in production — pprof, flamegraphs, and metrics to find and fix latency problems, not just describe them - EVM/blockchain transaction lifecycle experience: you understand how confirmations, reorgs, and on-chain state ripple into off-chain exchange correctness -
• Strong CS fundamentals: algorithms, data structures, and systems-level thinking - (Plus) Rust experience - (Plus) Redis, PostgreSQL, gRPC, Protobuf - (Plus) Kubernetes and AWS production operations BENEFITS - Competitive salary & equity - Unlimited PTO - Full Health, Vision, & Dental coverage - 401k match - Hardware setup: new MacBook Pro, big display, & accessories