Senior Full Stack Engineer

Location: UK/EU only | Remote Full time Permanent / Contract Existing Clients: Top 100 Lifesciences, MedTech and Pharma companies Type: Full-time | Contractor Company Description: Vamstar empowers leading global MedTech, Pharma, and Biotech organizations with agentic AI solutions designed to drive commercial success. The company focuses on critical functions such as tendering, pricing, market access, and contracts, integrating AI directly into existing workflows. Its solutions are trained on real-world data to deliver measurable margin impact and improved business outcomes. Vamstar acts as a strategic, vertical-specific partner to commercial teams, helping them unlock value and efficiency through advanced AI capabilities. Core responsibilities & objectives Design, build, and maintain full-stack applications end-to-end: responsive frontends, RESTful/GraphQL APIs, backend services, and data layers.Build and own user-facing features that surface complex AI/LLM capabilities: document viewers, search interfaces, agentic workflow dashboards, real-time streaming responses, and multi-step workflow UIs with proper error states, retries, and fallback handling.Write production-grade, well-tested code across the stack (TypeScript/React frontend, Python/Node.js backend) that handles large volumes of data and documents reliably.Own feature health: if a page is slow, an API is broken, or a user flow is wrong, it's on you.Work autonomously to project deadlines with minimal hand-holding. Key qualifications & skills (non-negotiable) 7+ years in full-stack development, shipping production web applications.Previously worked in a startup.Highly proficient in modern frontend frameworks (React, Next.js, or equivalent) and TypeScript.Strong backend development experience (Node.js,) building scalable APIs and services.Hands-on experience with databases and data-heavy applications (Postgres, Redis, Neptune or equivalent) and designing efficient queries and schemas.Real experience integrating AI/LLM capabilities into products: streaming LLM responses, RAG-powered search UIs, function/tool calling, async job handling, and observability.Deep understanding of application architecture, CI/CD, testing strategies, and performance optimisation at scale. Preferred background (strong signals) Experience with AWS at scale (Lambda, ECS, S3, CloudFront, or equivalent).Exposure to healthcare, life sciences, or regulated industries (e.g., GDPR, HIPAA-aware development).Built and shipped AI/LLM-powered features in production products used by real customers.Has debugged a production incident across frontend, API, and data layers — and knows why observability matters.Comfortable with DevOps basics: Docker, infrastructure-as-code, monitoring and alerting.Worked in a fast-moving startup where "that's not my job" doesn't exist.Expertise in supply chain, RFP, tender, marketplaces, web-scale B2C/B2B Interested? We're a distributed team solving hard problems that will reshape the healthcare industry for a generation. If you want ownership, not just tickets, we'd like to hear from you.