Founding Backend Engineer – Payments, Transactions & Platform

FrequentFan; New York (NY); On-site; USD 120,000 - 160,000; Full time

Benefits offered by this job

Competitive salary

Meaningful founding equity

Job summary

FrequentFan in New York City is seeking a backend engineer to build a revolutionary platform for premium sports ticketing and experiences. The role offers the chance to shape system architecture and work closely with founders in a fast-paced environment.

This full-time position focuses on backend engineering with a strong emphasis on data correctness and payment systems. A competitive salary and meaningful equity are part of the offer.

Qualifications

• 7 years of backend engineering with strong Java experience.
• Experience with systems where data correctness matters.
• Ownership of a system end-to-end in production.

Responsibilities

• Build the core platform from scratch.
• Shape the architecture and make real decisions.
• Work alongside founders with deep domain knowledge.

Skills

Backend engineering

Java

Spring Boot

Concurrency

Data correctness

Payment integration

Tools

PostgreSQL

AWS

Job description

Company: FrequentFan (pre‑seed, $1.2M raised)

Location: NYC – in‑person, full‑time

Reports to: CTO / Technical Co‑founder

About FrequentFan

FrequentFan is creating a new category – the first platform where credit card points can buy what they’ve never been able to buy before: premium sports tickets, team tunnel walkouts, F1 pit crew experiences, meetings with your sports heroes, and curated exclusive moments that aren’t available anywhere else in the market.

We give bank and credit card partners a single platform to offer their cardholders these experiences as point redemptions – driving higher engagement, faster point burn, and the kind of emotional loyalty that a flight upgrade never could.

We’re building bank‑grade products, our partners are financial institutions, and the platform has to meet the standards they expect: data correctness, auditability, compliance, and security. Every dollar and every point has to be accounted for exactly.

• Pre‑seed, $1.2M raised (September 2025)
• Founded by domain experts in banking, credit card loyalty, sports, and fintech
• Small team, high ownership, NYC‑based
• Competitive salary meaningful founding equity

The Role

You’ll be one of the first engineers building this platform from scratch. You’ll own a major piece of the core engine, shape the architecture around it, and make real decisions – not implement someone else’s spec.

Three backend lanes. You’ll go deep in one or two based on your strengths

Lane 1 — Transaction Systems: State machine orchestrating purchases through hold → payment → fulfillment → delivery. Immutable financial ledger (debits = credits at all times). Concurrency control, failure routing, reconciliation.

Lane 2 — Integrations & Payments: Payment integration, webhook handling, payment orchestration interface designed for multiple payment rails. Fulfillment backend – ticket intake, delivery credentials, status tracking.

Lane 3 — Platform & Operations: Monitoring, alerting, background jobs (hold expiry, orphan recovery, outbox processing), CI/CD, PCI compliance, production hardening.

Each lane carries real architectural decision authority – concurrency strategy, payment interface design, escalation thresholds, compliance approach. You’ll work alongside founders from banking, sports, and fintech who understand the domain deeply. Your job is to turn that domain knowledge into a system that works at scale.

Requirements

Must Have

• 7 years backend engineering, strong Java experience (Spring Boot preferred). Production code from Week 1.
• Has built systems where data correctness matters more than speed – payments, financial systems, trading platforms, healthcare records, or similar.
• Has owned a system end‑to‑end in production – responsible for correctness, reliability, and incident response, not just feature delivery.

Deep in at least two or more of these

• Concurrency — optimistic locking, CAS, race condition prevention.
• State machines / workflows — multi‑state lifecycle systems with defined transitions and failure routing.
• Immutable ledger / double‑entry — append‑only audit logs, debits = credits invariants.
• Payment integration — payment APIs where holds, captures, refunds, and timing have real financial consequences.
• Monitoring & production ops — alerting, background job systems, escalation infrastructure for production traffic.
• Compliance & hardening — PCI SAQ, SOC II, or equivalent. Load testing or performance profiling that found real bottlenecks.

Strong Plus

• Stripe experience (PaymentIntent lifecycle, webhooks, disputes)
• PostgreSQL depth – query optimization, locking, connection pooling
• Has processed real money, not just data that represents money
• Experience using AI coding tools (Claude Code, Codex, Cursor) to accelerate development

How We Build

We’re an AI‑native engineering team. Claude Code, Codex, Greptile, Conductor, and more are part of our daily workflow. AI handles boilerplate so you can focus on the hard problems.

Prior experience with these tools isn’t required, but you should be comfortable adopting AI tooling, or excited to start.

Technical Environment

• Stack: Java, Spring Boot, PostgreSQL (RDS), AWS (Fargate, CDK), GitHub Actions
• Patterns: Event‑sourced state machine, immutable append‑only ledger, outbox pattern
• AI Tooling: Claude Code, Codex, Greptile, Conductor, and more

This Role Is Probably Not For You If

• You’ve primarily built CRUD applications without financial or transactional complexity
• You’re looking for a remote role – this is NYC in‑person, no exceptions
• You haven’t owned a production system end‑to‑end
• You’re not open to working with AI coding tools daily

To apply

Send your resume and a short answer (2‑3 sentences) to [e-mail].

Pick the question that best fits your experience

1. Describe a system you built where data correctness mattered more than speed. What went wrong (or almost went wrong) that taught you this?
2. Tell us about a production integration that broke in a way the documentation didn’t warn you about. How did you find it and fix it?
3. Describe a time your monitoring or alerting caught something before it became an incident – or a time it didn’t and should have.

No Easy Apply. No generic cover letters. We read every real answer.