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

INFRO; Northern (KY); Hybrid; USD 120,000 - 180,000; Full time

Job summary

INFRO is seeking a senior backend engineer to own large parts of the gateway path between customer applications and AI provider accounts. You will design and ship end-to-end gateway features in TypeScript running on Cloudflare Workers, backed by Postgres, focusing on speed, correctness under concurrency, and transparent measurement.

You will build provider adapters, ensure idempotency, retries, and robust error handling, write migrations and tests, participate in on-call rotations, and document

Qualifications

• 5+ years building production backend services.
• Experience with systems handling real traffic and billing data preferred.
• Strong TypeScript, HTTP, SSE and JSON wire formats understanding.

Responsibilities

• Design and ship gateway features end to end: request handling, provider adapters, streaming, and error taxonomy.
• Add support for new provider kinds and wire formats without special-casing the router.
• Keep hot path fast: avoid tokenizing per request, unbounded queries, and slow waits.
• Write migrations and tests against a real Postgres, including concurrency edge cases.
• Participate in an on-call rotation and document runbooks for shipped features.

Skills

TypeScript

HTTP

SSE

JSON wire formats

PostgreSQL

Distributed systems

Idempotency

Retries

Concurrency

Tools

Cloudflare Workers

Durable Objects

KV

Job description

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 HTTP, 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.