Senior Backend Engineer, Payments

Polymarket is looking for a senior backend engineer to build and scale the payments infrastructure that powers deposits, withdrawals, and money movement across the platform.

Responsibilities

Build payments infrastructure: Design and lead migrations from legacy or monolithic systems to reliable, distributed payments services (Go, gRPC, DynamoDB/MySQL) with no disruption to production money movement; Integrate with financial rails: Build and maintain integrations with payment processors, banking rails, and card networks to support deposits, withdrawals, and settlement; Ship regulated features: Partner cross-functionally with Product, Compliance, and Design to deliver high-stakes financial features such as KYC/EDD, fraud checks, and reconciliation; Own correctness and auditability: Take ownership of production on-call for money-movement systems where correctness, reliability, and auditability are non-negotiable; Drive team process: Mentor engineers, onboard new hires, and lead backlog grooming and tech-debt reduction efforts; Collaborate cross-functionally: Work closely with engineers across the platform to keep payments systems tightly integrated with the broader exchange

Requirements

Senior-level backend engineering experience with payments, fintech, or financial-data integrations (processors like Stripe, banking rails, card networks); Proven track record leading migrations from legacy/monolith systems to reliable distributed services (Go, gRPC, DynamoDB/MySQL) without production disruption; Experience partnering with Product, Compliance, and Design to ship regulated or high-stakes financial features (KYC/EDD, fraud, reconciliation); Comfortable owning production on-call for money-movement systems where correctness and auditability are critical; Track record of mentoring, onboarding, and driving team process (backlog grooming, tech-debt reduction)

Nice to have

Experience in crypto, prediction markets, or other high-growth regulated fintech environments; Experience deploying systems in cloud environments (AWS/GCP) and using containers

Benefits

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