Full Stack Agentic Developer
Summary
Full stack developer at Umain (the engineering practice of the Eidra UK consultancy) in London who delivers client products using AI coding agents: writing specs, orchestrating parallel agents, and selecting models. Day to day combines spec-driven delivery and agent orchestration with full stack builds in TypeScript, React/Next.js, Node.js/NestJS on cloud (GCP/AWS/Azure) with Terraform.
About Eidra UK
Eidra is a collective of around 1,600 people across design, technology, data and business transformation companies, including Umain, Kurppa Hosk, Above and Curamando. Eidra UK brings that capability together for UK clients from our London base.
Umain is the engineering practice inside Eidra UK. We design, build and run digital products at scale: apps with 400M+ downloads, platforms serving 50M+ monthly active users, and backends handling tens of thousands of requests per second.
We are building Eidra UK around an AI-first way of delivering software. This role sits at the centre of that.
The role
We’re looking for a full stack developer who already works agentically. You write clear specs, run multiple agents in parallel against them, choose the right model for each job, and take full ownership of what ships.
You’ll work on client products end to end, from shaping requirements with stakeholders through to production. You’ll also help define how Eidra UK builds software with agents: the practices, tooling and standards the rest of the team uses.
How we build
We start from a clear spec, break the work into tasks agents can complete, run those agents in parallel, verify the output with tests, evals and review, then ship. The spec is the source of truth. Agents do much of the implementation. You own the spec, the orchestration and the quality of the result.
What you’ll do
Spec driven delivery
Define requirements in a structured way: identify the actors, describe their use cases, then derive the features that serve them.
Turn client needs into specs that both people and agents can build against: clear scope, acceptance criteria, interfaces and constraints.
Keep specs, tests and code in step as the product changes.
Break work into units that agents can complete and verify independently.
Agent orchestration
Run and coordinate agent swarms: parallel agents, subagents and specialised roles (planning, implementation, review, testing).
Build and maintain the supporting tooling: MCP servers, agent skills, prompts, context files and isolated workspaces.
Design the checks that keep agent output trustworthy: test coverage, evals, guardrails and human review points.
Model selection and mixing
Combine frontier and open-weight models to deliver results.
Route work by capability, cost, latency and data sensitivity, including self-hosted or private deployments where client data requires it.
Measure model performance on real tasks and change the mix when the evidence says so.
Full stack engineering
Build secure, scalable web applications with TypeScript, React and Next.js.
Build backend services and APIs with Node.js and NestJS.
Create reusable UI components using design system principles.
Work with cloud infrastructure (GCP, AWS or Azure), infrastructure as code with Terraform, and CI/CD pipelines.
Build observable systems with metrics, logging and tracing, including for LLM and agent behaviour in production.
Clients and team
Work directly with clients and cross-functional teams across design, product and data.
Explain agentic delivery, its trade-offs and its limits to technical and non-technical audiences.
Share what works: pair with colleagues, document patterns and help raise the agentic practice across Eidra UK.
What we’re looking for
3+ years of professional full stack experience, with strong TypeScript, React/Next.js, Node.js and core web fundamentals.
Hands-on experience delivering production software with coding agents (for example Claude Code, Codex, Cursor or similar), beyond autocomplete.
Strong requirement definition experience, working from actors to use cases to feature definitions with clear acceptance criteria.
A working spec driven development practice. You can show specs you’ve written and what agents built from them.
Experience running multiple agents in parallel and coordinating their output.
Practical experience using both frontier and open-weight models, with a view on when each is the right choice.
Strong engineering judgement. You read and review agent output critically and you own the result as your own code.
Comfort with ambiguity, and the consulting instinct to work it through with clients.
Curiosity. The tools change monthly and you enjoy keeping up.
Nice to have
Building agentic features into client products: tool calling, RAG, MCP servers, multi-agent workflows.
Running open-weight models in production (for example vLLM, Ollama or managed inference).
LLM evaluation and observability tooling.
Contributions to open source agent tooling or published writing on agentic engineering.
Tailwind CSS, Storybook and design system work.
Experience in a consultancy or agency setting.
Working setup
London is the default office. You’ll work remotely when it suits the team or the client.
Don’t match every point? Apply anyway. We care more about how you think and what you’ve built than about ticking every box.
