Senior Backend Engineer — AI Gateway (TypeScript + Postgres)

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

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