Senior Backend Engineer, Onchain
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 world-class backend engineer with deep blockchain knowledge to join our Onchain Execution team. This team owns the systems that sit between Polymarket's product and the chain - the relayers, transaction pipelines, RPC infrastructure, and settlement logic that make every trade possible. You'll be working on technically demanding problems at the intersection of distributed systems, blockchain protocols, and high-throughput backend engineering.
The ideal candidate brings both fundamentals (clean code, solid databases, well-designed APIs) and fluency in how EVM networks actually work under the hood. If you've built or maintained relayer systems, worked on scalable RPC infrastructure, or contributed to core blockchain node software, this role is a strong match.
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 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
About Polymarket
Polymarket is at the forefront of the decentralized information and prediction market revolution, leveraging cutting-edge blockchain technology to create a more transparent and efficient way to bet on real-world events. We're building a platform where users can trade on their beliefs about everything from politics to pop culture, fostering a global community driven by data and conviction. Our mission is to democratize access to information and enable price discovery in a trustless environment, fundamentally reshaping how people engage with and understand the world. Our team thrives on innovation, intellectual curiosity, and a deep-seated belief in the power of Web3 principles. We champion a culture of open collaboration, radical transparency, and continuous learning, encouraging every team member to contribute their unique perspective to solve complex challenges. We are a group of passionate builders, designers, and strategists united by a vision for a decentralized future, where markets are fair, accessible, and censorship-resistant. At Polymarket, your work directly impacts the evolution of decentralized finance and information. If you're eager to make a significant impact in the nascent but rapidly expanding blockchain space, Polymarket offers an unparalleled opportunity. Join us to contribute to a platform that empowers users, challenges traditional financial systems, and puts the power of prediction back into the hands of the people. We're looking for individuals who are not just skilled but are also true believers in the potential of crypto to create a more informed and equitable world. Come build the future with Polymarket.
Ready to Apply?
To submit your application for this position, please visit Polymarket's official website and follow their application process.