Senior Backend Engineer

## 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.

## What You'll Do - **Build and maintain onchain execution infrastructure.** Design and operate the relayer systems, transaction pipelines, and settlement logic that power Polymarket's markets end-to-end. - **Architect high-performance backend systems.** Build reliable, scalable APIs and services that handle high transaction volumes and real-time data with low latency. - **Own RPC and chain connectivity.** Implement and scale the endpoints and integrations that keep Polymarket reliably connected to EVM networks. - **Optimize performance and reliability.** Push the limits of throughput and efficiency across our onchain systems, ensuring seamless operation as volume grows. - **Enhance security and fault tolerance.** Apply best practices for secure, highly available distributed systems — especially in adversarial onchain environments. - **Contribute to code quality.** Participate actively in code reviews and help maintain a high engineering bar across the team. - **Stay close to the frontier.** Track developments across EVM ecosystems and blockchain infrastructure, and bring relevant innovations back to Polymarket's stack.

## What We're Looking For - 5+ years of experience in backend development - Strong fundamentals: clean, well-tested code; solid database design (PostgreSQL or equivalent); well-structured APIs - Solid understanding of how EVM networks work: transaction lifecycle, gas mechanics, mempool dynamics, smart contract interactions - Experience with systems-level languages: Golang is strongly preferred; Rust or C++ also valued - Familiarity with blockchain infrastructure: RPC nodes, event indexing, relayer architectures, or similar - Excellent problem-solving skills and the ability to work through ambiguous, high-stakes technical challenges - **(Plus)** Direct experience building or operating a relayer system - **(Plus)** Experience with Ethereum rollup technologies (Arbitrum Nova, Optimism, etc.) - **(Plus)** Experience with BFT consensus engines, libp2p, or core node software - **(Plus)** Open source contributor in the blockchain ecosystem - **(Plus)** Active on [ethresear.ch](http://ethresear.ch) or similar protocol research forums

## Benefits - Competitive salary & equity - Unlimited PTO - Full Health, Vision, & Dental coverage - 401k match - Hardware setup: new MacBook Pro, big display, & accessories

Polymarket is the world's largest prediction market platform where users trade on the outcomes of real-world events such as politics, sports, economics, and more, using USDC cryptocurrency on the Polygon blockchain. It provides real-time odds reflecting news, polls, and events, and operates globally with a US-regulated entity.