Brainback
Log inSign up
careersengineering

Founding Backend Engineer

You'll own the model orchestration layer — routing between Sonnet and Haiku, prompt caching, streaming, output guard. Deep familiarity with LLM APIs required.

Engineering Remote (US/EU) or NYCFull-timeStaff
apply
Send us a note

No formal cover letter. Send a résumé + a paragraph on why the “refuse to give the answer” stance appeals to you.

quick facts
  • teamEngineering
  • seniorityStaff
  • employmentFull-time
  • locationRemote (US/EU) or NYC
we read every application ourselves

What you’ll do

  • Own the tutor engine: system prompt design, model routing, cache strategy.
  • Design the streaming architecture end-to-end.
  • Instrument and optimize inference cost across every route.
  • Build the evaluation harness that runs before every model upgrade.

What you bring

  • 6+ years backend engineering, at least 2 with LLM APIs in production.
  • Fluent in Node/TypeScript and Postgres.
  • Have shipped a product where inference cost was a real line item.
  • Comfortable making cost/quality tradeoffs with real data.

Bonus, not required

  • Familiarity with Anthropic's prompt caching.
  • Background in eval design.
  • Experience running LLMs behind an SLA.
also open

Other roles we're hiring for.

Engineering·Staff
Founding Frontend Engineer

You'll own the Brainback web app end-to-end — from the Learn mode chat UX to the recall queue to the parent dashboard. Next.js 15, React 19, Tailwind, TypeScript. Deep taste required.

role
Research·Lead
Learning Scientist

You'll bring rigorous learning-science thinking into the product. Design experiments, review the literature, shape the pedagogical stance, and write.

role
Design·Senior
Brand Designer

You'll own the visual identity — typography, illustration, motion, the Brainback book. Editorial sensibility required.

role
Design·Senior
Product Designer, Learn Mode

You'll design the surfaces where learning actually happens. Learn mode chat, hint ladder, explain-back flow, recall queue. Ship in code alongside engineering.

role

start now

Take back the semester you actually meant to have.

Sign up in ten seconds — magic-link email, no password to remember. Free during beta.

Sign up — it's free