Senior Backend Engineer, Exchange Systems

Role Description

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 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.

Qualifications

• 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.