Senior Backend Engineer

👶 About Junior

We’re building cutting-edge LLM-powered tools to supercharge the investment research process for private market investors. Our clients include several of the world’s top 10 private equity and consulting firms, and are responsible for investing billions of dollars annually. We’re a profitable, bootstrapped company with a growing team of 17 based in London and NYC.

You can read more about the company mission & values here.

As a Backend Engineer
, you’ll help build and scale the systems that power our AI-driven research platform. This is a systems-level role - ideal for engineers who love thinking about data flows, orchestration, and performance across complex distributed systems.

As one of our
first engineering hires, you'll have the unique opportunity to:

• Ship quickly
• Architect and scale backend systems that support high-throughput LLM interactions, vector search, and multi-agent orchestration.
• Stitch together AI infrastructure across model providers, data stores, and internal APIs to create cohesive, performant systems.
• Own reliability and observability, helping us evolve our database (Postgres / Click House) and job orchestration systems.
• Prototype new backend capabilities (retrieval pipelines, caching layers, async task queues) that let us build faster and smarter.
• Shape our engineering culture

We're looking for product-minded backend engineers who:

• Based in NYC
  ,
  *** we are 5 days a week in person
• Are excited by the intersection of AI infrastructure and systems design
• Have experience leading projects end-to-end
• Are eager to contribute to product decisions
• Are proficient in our tech stack:
  Next.js, Type Script, PostgreSQL
• Feel like you are never building fast enough

Bonus points for experience working on:

• Retrieval/embeddings/prompt orchestration
• Built internal infrastructure / dev tools @ startups

All the usual benefits (competitive pay and equity, private healthcare etc). Unusual benefits:

• Gym membership
• In-office cook
• Summers working in Greece by the beach

If you're excited about the opportunity to drive innovation at Junior, we'd love to hear from you! Email us at careers with your resume and a brief introduction. We can't wait to meet you! 🙌