About the role

Senior Product Engineer designing scalable backend systems for Railway's platform. Architecting and implementing solutions for billing, payment, and fraud detection services.

Responsibilities

Architect and scale the pipelines that turn raw usage into accurate, real-time billing — metering, aggregation, rating, and invoicing across millions of events, from ingestion in ClickHouse to the rating engine.
Build payment flows that are correct under concurrency and partial failure: idempotent charges, retries, reconciliation, and clean handling of provider edge cases (Stripe and beyond).
Develop fraud and abuse detection — signal collection, real-time scoring, automated mitigation — that protects platform margin without getting in legitimate users' way.
Scale the systems everything else depends on: Postgres under heavy write load, Node.js services under pressure, and long-running workflows orchestrated with Temporal where exactly-once semantics and durability actually matter.
Build TypeScript + GraphQL APIs where correctness and auditability are non-negotiable.
Write Engineering Requirement Documents to take something from idea, to defined tasks, to implementation, to monitoring its success and scaling it further.
Contribute to our open-source repositories (CLI, Typescript SDK, Railpack, etc.) — Rust experience, or the desire to learn it, helps here.
Be oncall from time to time.

An ability to autonomously lead, design, and implement backend systems where correctness, consistency, and auditability are first-class requirements.
A track record of scaling systems — you've taken a pipeline, service, or database that was falling over and made it handle 10x, and you know which tools to reach for (and when polling stops being enough).
Deep expertise in Postgres and relational data modeling — you reach for the right consistency guarantees, understand the cost of getting them wrong, and know how Postgres itself behaves at scale.
Strong working knowledge of Node.js internals — the event loop, memory behavior, and what to do when a service degrades under load.
Experience managing complex asynchronous and long-running backend jobs, ideally with a workflow engine like Temporal, for things like billing runs or payment reconciliation.
Familiarity with the realities of money movement: payment providers, idempotency, retries, reconciliation, and their failure modes. Direct billing, payments, or fraud experience is a strong plus.
A security and abuse-aware mindset — you instinctively think about how a system can be gamed, and you design accordingly.
A desire to be a part of the entire project development process, from research gathering and planning, to implementation and monitoring.
Great written and verbal communication skills for expressing ideas, designs, and potential solutions in a mostly-asynchronous manner.