Senior Full-Stack AI Engineer — Impactful Sustainability Tech

Annwn; Greater London; On-site; GBP 90,000 - 140,000; Full time

Job summary

Annwn in the United Kingdom is seeking Full Stack AI Engineers to build agentic systems that make a difference. You'll work at the core of our platform, designing and implementing AI components that ingest and structure data, reason across complex domains, and run simulations.

You will own meaningful parts of the architecture, influence design choices, and engage directly with customers tackling real-world sustainability challenges.

Qualifications

• Strong software engineering fundamentals.
• 7+ years of experience building full‑stack applications.
• Proficiency with modern web technologies (React/Next.js/TypeScript).
• Experience backend development using Python.
• Comfort with messy real‑world data.
• Clear communicator capable of designing and explaining complex systems.
• Experience using coding agents to accelerate work (Codex/Claude Code).

Responsibilities

• Ingest and structure unstructured sustainability data.
• Reason across complex, uncertain domains.
• Run simulations and scenario analysis.
• Improve continuously via feedback and memory.
• Own architecture decisions and influence platform design.
• Directly engage with customers addressing real-world sustainability problems.

Skills

Strong software engineering

7+ years full-stack experience

Clear communicator

Data wrangling

Codex / Claude Code usage

Tools

React

Next.js

TypeScript

Python

Job description

Annwn in the United Kingdom is seeking Full Stack AI Engineers to build agentic systems that make a difference. You'll work at the core of our platform, designing and implementing AI components that ingest and structure data, reason across complex domains, and run simulations.

You will own meaningful parts of the architecture, influence design choices, and engage directly with customers tackling real-world sustainability challenges.