About this role
Salary: £45,000 - 45,000 per year
Requirements: Significant backend engineering experience in TypeScript and Node.js.Experience building LLM-backed systems that run in production, with informed views on how they fail.Experience designing and operating distributed systems.Practical experience of correctness under partial failure, including idempotency, at-least-once delivery, safe retries, and backwards compatibility between services that deploy independently.Solid understanding of relational databases, including schema design and safe migration.Clear technical writing skills; we can produce a design document that a reviewer can act on.A product mindset, motivated by user outcomes rather than only system design, with the ability to measure before optimising and revert changes that do not hold up.Preferred qualifications include experience with durable execution or workflow engines such as Restate, Temporal, or Inngest, or a comparable system built yourself.Preferred qualifications include Python and LLM application frameworks such as FastAPI, LangChain, or LangGraph.Preferred qualifications include observability and LLM instrumentation tools such as OpenTelemetry and Langfuse.Preferred qualifications include multi-tenant SaaS where tenant isolation is a design constraint.Preferred qualifications include infrastructure as code such as Terraform and Kubernetes.Preferred qualifications include search and retrieval at scale, such as Elasticsearch, vector search, and knowledge graphs.Preferred qualifications include functional programming, either in TypeScript or in a functional language. Responsibilities: Design and evolve the workflow definition model, including control flow, fan-out, conditional execution, data passing between steps, and static validation that rejects invalid workflows before they run.Build the durable execution engine, including checkpointing and resumption after failure, retry and abandonment policies, and idempotency guarantees.Instrument runs that cross several services and two languages so that latency and token spend can be attributed to individual steps, feeding pricing decisions.Integrate LLM capabilities with structured outputs, guardrails, retries, citation integrity across steps, and decisions about where deterministic code should replace a model call.Write design proposals, break large changes into shippable increments, implement the hardest parts, and own the result in production.Work in a full-stack engineering environment weighted towards backend and platform, with TypeScript, Node.js, Restate, PostgreSQL, Google Cloud, and Azure.Work in our Python-based GenAI service as needed. Technologies: AIAzureBackendCloudElasticSearchFastAPIFlowSupportKubernetesLLMLangfuseOpenTelemetryPostgreSQLPythonTerraformTypeScriptNodeJSApolloArgoCDDevOpsFine-tuningFrontendGitGitHubGraphQLModel TrainingReactRedis More:
We are Causaly, and we are redefining how humans acquire knowledge and develop insights in biomedicine through our AI-powered platform. Our system helps researchers and decision-makers discover and interpret evidence from millions of scientific publications, clinical trials, regulatory documents, and other complex data sources in minutes. We are building a world-leading biomedical knowledge platform powered by a high-precision Knowledge Graph and GenAI capabilities, already used by leading biopharmaceutical organizations to accelerate drug discovery, improve safety, and support better decision-making. Backed by top-tier investors including ICONIQ, Index Ventures, Pentech, and Marathon, we are scaling rapidly and expanding our product suite and market presence. This is a full-time hybrid technology role based in London. We offer competitive compensation, private medical and dental insurance, life insurance at 4x salary, a personal development budget, an individual wellbeing budget, 25 days holiday plus bank holidays, and your birthday off. You will have the potential to make a real impact and accelerate your career as part of an international team building a transformative AI product. We are an equal opportunity employer and welcome applications from all backgrounds.
last updated 36 week of 2026