Senior Software Engineer - Pay & Safety

ABOUT HANDSHAKE Handshake was founded on a simple belief that everyone deserves a path to a great career, regardless of where they went to school or who they know. Today, we power 25 million job seekers, 1 million+ employers, and 1,600 educational institutions. In 2025, we started Handshake AI and built the fastest-growing AI data business in history. We work directly with frontier AI lab researchers to create evaluations, publish benchmarks, and push the boundary of data. We’ve grown from $0 to ~$1B run rate and pay ~$60M to over 30K individuals every month. Why join Handshake now: - Shape how every career evolves in the AI economy, at global scale, with impact your friends, family and peers can see and feel - Partner hand-in-hand with world-class AI labs, Fortune 500 partners and the world’s top educational institutions - Work together with engineers, scientists, operators, and more from Palantir, Meta, Scale AI, and former YC founders - Build a massive, fast-growing business with billions in revenue About Handshake AI Human data is the core infrastructure to AI advancement. Frontier AI labs currently improve model capabilities with various data-intensive post-training techniques. We believe that data spend for AI training will increase by 3-5x in the next few years and continue for much longer as models take on new domains. Handshake AI supports all of the frontier AI labs, working on their most complex data at the largest scale. ABOUT THE ROLE As a Senior Software Engineer on the Pay squad, you'll own the systems that move money to Handshake AI's global fellow workforce. That includes earnings calculation, payout generation, Stripe-backed disbursement, and the operator tooling that runs every pay cycle. You'll also be helping us build out a much more sophisticated Trust & Safety surface area: KYC and identity verification, sanctions and fraud screening, and time-tracking audit systems that catch suspicious activity throughout Handshake AI. This is a role for engineers who treat reliability, auditability, and resilience as first-class design constraints. Pay can't go down. Ban decisions can't be silent. Webhooks can't be lost. You'll set the bar for how these systems are designed, deployed, and verified. Our work spans across microservices and integrations with payment and trust and safety providers. WHAT YOU’LL DO - Design and build payout and money-movement systems on top of Payment Service Providers, including onboarding, KYC, country and payout-method support, webhook reconciliation, retries, and rate-limit handling, with zero-downtime rollout and full auditability for every state change. - Build out a robust and flexible payment and incentives platform that powers how fellows are compensated, rewarded, and retained across every project we run. - Build the Trust & Safety stack: KYC and re-verification flows, sanctions and fraud screening, ban and suspicious-account state transitions, and time-tracking audits over activity, time confirmations, and pay rates. - Own operator tooling, including the Pay admin dashboard, ledger, and operations that let our ops team run pay weeks safely. - Lead end-to-end on schema design, migrations, and backfills across Postgres and design rollouts that are safe to deploy. - Set the bar for engineering practices on the squad through system design reviews, incident response, runbooks, and observability, and mentor other engineers through code review and architectural guidance. WHAT WE’RE LOOKING FOR - 5+ years of professional software engineering experience, with meaningful time spent owning production systems where correctness and uptime matter (payments, fintech, identity, fraud, infrastructure, or similar high-stakes domains). - Strong system design fundamentals for highly reliable, zero-downtime, auditable, and resilient systems: expand-contract migrations, idempotency, retries and backoff, dual-writes and backfills, append-only audit logs, and reconciliation jobs. - Deep proficiency with