Founding Engineer (Python)

Stealth Start-Up

London
Permanent
Hybrid
£70,000 - £100,000/year
PythonMachine LearningCloud Infrastructure (AWS/GCP/Azure)

Role Overview

As a Founding AI Engineer, you’ll be more than a developer, you’ll be a co-creator of the company’s DNA. You’ll take end-to-end ownership of our AI infrastructure and product experience: architecting systems, integrating LLMs, and shaping how humans and intelligent agents collaborate.

You’ll thrive in ambiguity, move fast, and balance technical depth with product clarity. This is a rare opportunity to build from scratch and see your work directly influence product, culture, and company trajectory.

Key Responsibilities

  • Design, develop, and deploy AI-powered full-stack features using Python (backend, AI orchestration) and React/TypeScript (frontend).
  • Build, fine-tune, and integrate large language models (LLMs) via APIs (OpenAI, Anthropic, or LangChain-style frameworks).
  • Own the full ML lifecycle, from data collection and preprocessing to model training, evaluation, deployment, and monitoring.
  • Develop API-first architectures (REST/GraphQL) that enable seamless integration and scalability.
  • Build and maintain secure, privacy-by-design data models using PostgreSQL and cloud-native infrastructure (AWS, GCP, or Azure).
  • Implement robust DevOps practices with Docker, GitHub Actions, and CI/CD pipelines.
  • Collaborate directly with founders to define the technical roadmap, product strategy, and engineering culture.
  • Balance speed and rigor, shipping quickly while building foundations for long-term scale.

Required Skills & Qualifications

  • Minimum of 3 years of relevant experience as a Software Engineer or Machine Learning Engineer.
  • Strong full-stack experience in Python (backend + ML) and React/TypeScript (frontend).
  • Proven experience building and deploying ML models in production environments.
  • Deep understanding of machine learning concepts, algorithms, and frameworks (e.g., PyTorch, TensorFlow, scikit-learn).
  • Experience integrating LLMs and designing AI agent systems or orchestration layers.
  • Strong understanding of data modeling, security, and privacy principles.
  • Skilled in DevOps tools and modern CI/CD workflows (Docker, GitHub Actions, etc.).
  • Entrepreneurial mindset, thrives in chaos, works autonomously, and delivers outcomes.

Nice-to-Have Qualifications

  • Prior experience in an early-stage startup or founding-engineer capacity.
  • Contributions to open-source AI/ML projects.
  • Experience with MLOps tools (MLflow, Kubeflow) or container orchestration (Kubernetes).
  • Interest in product design, UX, and building tools founders love.

Who You Are

  • You move fast, learn faster, and own outcomes.
  • You care deeply about clarity, speed, and user experience.
  • You’re comfortable wearing multiple hats, from data pipelines to design polish.
  • You want to build the next wave of AI-native products, not just use them.