Senior Backend Engineer

👶 About Junior We're building cutting-edge LLM-powered tools that supercharge investment research for the world's most demanding deal teams. Our clients include several of the top 10 global private equity firms, Big 4 professional services firms, and leading consulting practices: organisations responsible for deploying billions of dollars annually. We're a profitable, bootstrapped company with a growing team of ~43 people based in London and New York. We 10x'd our revenue in 2025 and are on track to grow 2-3x again this year. Junior saves clients an average of 10 hours per week, and we're expanding fast into new verticals including investment banking, hedge funds, and research firms. You can read more about the company mission & values here. 💡 Role Description 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. You'll Have The Unique Opportunity To Ship quicklyArchitect 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 / ClickHouse) 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 🔥 About You We're Looking For Product-minded Backend Engineers Who Are based in NYC and excited to work 5 days a week in personAre excited by the intersection of AI infrastructure, financial systems, and backend engineeringHave experience owning backend projects end-to-end — from architecture through to productionAre strong in Python and TypeScriptHave worked with PostgreSQL and care about data modelling, reliability, and system designAre comfortable building APIs, internal tools, workflows, and infrastructure that support real customersAre eager to contribute to product decisions, not just execute ticketsFeel like you are never building fast enough Bonus Points For Experience Working On Billing, payments, usage-based pricing, or financial workflowsInternal infrastructure / dev tools at startupsData pipelines, workflow orchestration, or event-driven systemsRetrieval, embeddings, or prompt orchestration 🌵 Benefits All the usual benefits (competitive pay and equity, private healthcare etc). Unusual benefits: Gym membershipIn-office cookSummers working in Greece by the beach 📩 How To Apply If you're excited about the opportunity to drive innovation at Junior, we'd love to hear from you! Email us at careers@myjunior.ai with your resume and a brief introduction. We can't wait to meet you! 🙌