Senior Backend Engineer, Onchain

Polymarket

Backend Engineer in Polymarket's Onchain Execution team, focusing on blockchain infrastructure and high-performance systems. Contributing to backend engineering and optimizing onchain systems.

Posted 4/29/2026full-timeRemote • New York • 🇺🇸 United StatesSeniorWebsite

Tech Stack

Tools & technologies

Distributed SystemsGoNode.jsOpen SourcePostgresRust

About the role

Key responsibilities & impact

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.

Requirements

What you’ll need

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

Comp & perks

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

ATS Keywords

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Hard Skills & Tools

backend developmentclean codewell-tested codedatabase designAPIsEVM networksGolangRustC++blockchain infrastructure

Soft Skills

problem-solvingability to work through ambiguity