Backend Engineer - London

We’re building cutting-edge LLM-powered workflow tools to supercharge investment research for private market investors. Our clients include most of the global top 10 private equity and consulting firms - Junior already powers hundreds of billions of dollars invested annually. We’re a profitable, bootstrapped company with a growing team of 30+ based in London, NYC and Sydney.

You’ll design and build the systems that support our AI-driven research platform along with our commercial, product, and operations teams — automating workflows, improving decision-making, and enabling the company to move significantly faster. This is a high-ownership backend engineering role (~4+ years experience) where you’ll work across data pipelines, integrations, automation, and internal infrastructure.

You’ll have the opportunity to:

• 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 the architecture of internal data systems and pipelines.
• Build automation and integrations across product, CRM, and financial systems.
• Help shape engineering culture and internal infrastructure decisions.

Example Projects You’ll Work On:

• Customer Health Intelligence System: Design data pipelines that consolidate product usage, CRM data, and user feedback into a unified system of record. Build automated signals and alerts that detect churn risk, usage drops, or emerging product issues - enabling the team to act quickly.
• User Feedback → Product Development Pipeline: Build internal tooling that processes feedback calls with users. Use LLMs to extract themes, cluster feature requests, and surface the most important insights to the product team.
• Billing & Revenue Infrastructure: Design systems to support complex B2B pricing models — combining usage-based, seat-based, and platform fees. Automate invoicing, reconciliation, and financial reporting.
• Internal Data Platform: Build and own our internal data platform, integrating product telemetry, CRM data, and financial systems. Create reliable pipelines and APIs that power reporting, automation, and decision-making across the company.

We’re looking for a Backend Engineer who enjoys building systems that make a company run better. You might be a good fit if you:

• Are based in London and excited to work from our Farringdon office (5 days/week).
• Have experience owning technical projects end-to-end, from architecture through production.
• Enjoy translating business problems into clean technical systems and automation.
• Like building high-leverage internal platforms that make teams dramatically more efficient.
• Have strong experience with PostgreSQL and modern data platforms (Snowflake, BigQuery, Databricks, Firebolt, etc.).
• Write production code in Python, or TypeScript.
• Thrive in fast-moving startup environments and enjoy shipping quickly while maintaining strong engineering standards.

Bonus: Experience building AI-enabled workflows, automation systems, or internal developer platforms.

Benefits:

• Private health insurance.
• Gym membership (Third Space).
• Dinner when working late.
• Frequent team offsites (Crete, Upstate NY, Cancun).