Job Description
Senior Full Stack Engineer Location: Remote, EU/UK preferred Team: Engineering Type: Full-time contractor We are looking for a Senior Full Stack Engineer to join a small, high-impact engineering team. You will work across the product surface: React front end, NestJS backend, durable execution system, Postgres data layer and proprietary systems for evaluating and managing systems of LLMs. Some of this you may not have done before, but you will apply your transferable skills and experience! This role suits someone who enjoys a variety of challenges, extending the forefront of what it takes to deliver reliable and trustworthy AI systems, and making those things simple and a joy to use. You will understand product needs, design clean domain models, build reliable components, ship easy-to-use interfaces, and debug distributed execution behaviour when things get interesting. What You’ll Work On Build product features across our React/Vite frontend, NestJS backend, PostgreSQL data layer, and Temporal-powered worker stack. Develop new ways to benchmark and optimise LLM use, including error detection and correction and blocking AI-focused security attacks Identify where AI can meaningfully improve structured tasks (and not make things worse): extraction, classification, decision support, agentic tool use, document understanding, communication handling, and automation of tedious operational steps. Design and extend systems to proactively benchmark, monitor, manage and optimise LLM selection, quantify drift in production, and measure cost vs. performance Build APIs, data models, and tenant-aware authorization boundaries for workflows, executions, agents, connectors, inbox, dashboards, and configuration. Create polished interfaces for workflow authoring, execution monitoring, review queues, dashboards, and configuration-heavy SaaS workflows. Improve reliability through strong testing, runtime visibility, replay-safe changes, and careful debugging across UI, API, database,
