Contract Ruby Rails Jobs in Clifton, NJ (NOW HIRING)

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.

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.

• 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.

• 6+ 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 relational databases (PostgreSQL), data modeling, and schema evolution under load. You can defend why a given state is or isn't reachable.

• Strong backend skills in Ruby on Rails and/or TypeScript/Node, and willingness to work fluently across both.

• Comfort in React for operator and fellow-facing UI.

• Experience designing and operating asynchronous workflows (Temporal, Sidekiq, or similar) and integrating with third-party APIs that fail in interesting ways (Stripe, Deel, Hubstaff, or equivalents).

• Track record of leading technical projects end-to-end in ambiguous environments, with a bias toward shipping behind feature flags and verifying in production.

• Excellent communication and stakeholder management. You can partner with Ops, Finance, Legal, and Compliance and translate their requirements into system invariants.

• Track record of mentoring engineers and raising the engineering bar on a team.

• Prior experience building production payments, payout, or money-movement systems

• Background in Trust & Safety, fraud, KYC/AML, sanctions screening, or identity verification at scale.

• Experience with event sourcing, change-data-capture, or audit-log architectures where every state change is reconstructable.

• Experience operating comparable workflow orchestrators for long-running, idempotent business processes.

• Experience with regulated or compliance-driven workstreams (1099-NEC issuance, OFAC, GDPR/data deletion, SOC 2 controls).

Handshake delivers benefits that help you feel supported—and thrive at work and in life.

The below benefits are for full-time US employees.

🎯 Ownership: Equity in a fast-growing company

💰 Financial Wellness: 401(k) match, competitive compensation, financial coaching

🍼 Family Support: Paid parental leave, fertility benefits, parental coaching

💝 Wellbeing: Medical, dental, and vision, mental health support, $500 wellness stipend

📚 Growth: $2,000 learning stipend, ongoing development

💻 Office: Commuting support, free lunch, and gym in our SF office

🏝 Time Off: Flexible PTO, 15 holidays + 2 flex days

🤝 Connection: Team outings & referral bonuses

Compensation Range: $225K - $250K