Senior Product Engineer, Scalability

Our core mission at Railway is to make software engineers higher leverage. We believe that people should be given powerful tools so that they can spend less time setting up to do, and more time doing. Railway now powers workloads for millions of builders, and the systems underneath — usage metering, billing and payments, fraud and abuse protection, background workers, and the data pipelines that feed them all — have to scale every week. You'll be the person who architects that stack: making it fast, correct, and trustworthy at a volume that keeps growing. If you're looking to scale the backbone of an operating system for builders, we'd love to talk with you! Want to learn about our work culture? Here is a multi-part blog series that will help you see the unique ways our team works (Parts 1 , 2 , 3 , and 4 ). About the role This is a backend-leaning role focused on scaling systems. Billing and fraud will be a focus, but your remit spans every high-throughput system at Railway — workers, queues, event pipelines, and the databases underneath them. You'll own your work end-to-end, including when a feature reaches the UI. For this role, you will: 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 correctnes