Senior Backend Engineer, Gateway US - Remote September 16, 2026

The INFRO gateway sits between a customer's applications and the AI provider accounts they already hold. Every request is authenticated, checked against budgets and policy, routed to one of the customer's own provider connections, streamed back, and recorded with its latency, tokens and estimated provider cost. You will own large parts of that path. It runs as TypeScript on Cloudflare Workers with Postgres behind it, and it has to stay fast, correct under concurrency, and honest about what it measured. What you will do Design and ship gateway features end to end: request handling, provider adapters, streaming, and the error taxonomy customers build against. Add support for new provider kinds and wire formats (OpenAI-compatible, Anthropic Messages, Responses) without special-casing the router. Keep the hot path cheap: no tokenizing per request, no unbounded queries, and nothing that waits on a mail server or a slow write. Write migrations and tests against a real Postgres, including the concurrency cases a unit test cannot see. Take part in an on-call rotation for the gateway and write the runbook entry for anything you ship. What you will bring 5+ years building production backend services, with at least one system that handled real traffic and real money or billing data. Strong TypeScript, and comfort reading SSE and JSON wire formats byte by byte. Solid Postgres: schema design, migrations, indexes, transactions, and knowing when a query will scan a partition it should not. Experience with idempotency, retries and race conditions in distributed systems. Clear written communication. Most decisions here are made in writing. Nice to have Cloudflare Workers, Durable Objects, KV or Queues in production. Hands-on work with LLM provider APIs (OpenAI, Anthropic, Bedrock, Vertex, Azure OpenAI). Hono, Drizzle, or another edge-first TypeScript stack. #J-18808-Ljbffr INFRO