Senior Backend Engineer (Fintech)

TL;DR

Senior Backend Engineer (Fintech): Building and scaling the payments infrastructure that powers deposits, withdrawals, and money movement with an accent on distributed systems, financial integrations, and regulatory compliance. Focus on designing reliable services, ensuring auditability of financial transactions, and leading migrations from legacy systems.

Location: On-site in New York

Company

Polymarket is the world's largest prediction market platform, enabling users to trade on real-world events through a transparent, peer-to-peer marketplace.

What you will do

• Design and lead migrations from legacy or monolithic systems to reliable, distributed payments services using Go, gRPC, and DynamoDB/MySQL.
• Build and maintain integrations with payment processors, banking rails, and card networks.
• Partner with Product, Compliance, and Design to deliver regulated financial features like KYC/EDD, fraud checks, and reconciliation.
• Take ownership of production on-call for money-movement systems where correctness and auditability are non-negotiable.
• Mentor engineers, onboard new hires, and drive team processes like backlog grooming and tech-debt reduction.

Requirements

• Senior-level backend engineering experience with payments, fintech, or financial-data integrations.
• Proven track record leading migrations from legacy systems to distributed services without production disruption.
• Experience partnering with cross-functional teams to ship regulated or high-stakes financial features.
• Comfortable owning production on-call for critical money-movement systems.
• Track record of mentoring, onboarding, and driving team process.

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.

Culture & Benefits

• Competitive salary and equity package.
• Unlimited PTO policy.
• Full Health, Vision, and Dental coverage.
• 401k match.
• Hardware setup including a new MacBook Pro and accessories.