Principal Full Stack Engineer

Location/s:
London

Mott Mac Donald is a global engineering, management, and development consultancy with over 20,000 employees across more than 50 countries and 140+ offices. We work across incredible global industries, delivering exciting work that is defining our future and making an important societal impact in the communities we serve. Our people power our performance – we succeed when they do. With countless opportunities to collaborate, learn, and grow, the possibilities for excellence are as varied as every individual.

Whether you want to grow as a subject matter expert or broaden your experience with roles across our international community, you're surrounded by global specialists who want to combine their expertise and champion you to be your best. As a proudly employee-owned business, we benefit our clients, our communities, and each other, investing in creating the right space for everyone to feel empowered, included, and valued.

Whatever your ambition, Mott Mac Donald is where people come to be brilliant.

Mott Mac Donald's support services are the driving force behind our organisation enabling us to run efficiently and effectively. The team works collaboratively to offer specialist advice, best practice and technology to all areas of our business specifically designed for our global reach.

We're seeking a Principal Full Stack Engineer to lead the design, development, and scaling of AI-powered digital products that serve infrastructure, engineering, and consulting professionals around the globe. This is a hands‑on leadership role that blends deep technical skills with strategic thinking. You'll balance the role of individual contributor while providing technical direction and mentoring a small cross‑functional team of engineers and data scientists, helping ensure excellence and strong delivery outcomes.

• Build scalable products:
  Design, build and maintain robust, secure full‑stack applications that integrate AI/ML models and serve our external clients and internal users across Mott Mac Donald at global scale.
• Lead delivery:
  Take end-to-end technical ownership of digital product initiatives—from architecture and development through deployment, monitoring, and iteration.
• Mentor and manage:
  Support the growth and effectiveness of a small team of engineers and data scientists, promoting best practices in code quality, testing, and collaboration.
• Architect with intent:
  Contribute to and refine system architecture decisions to support modularity, reuse, performance, and long‑term maintainability.
• Work across Disciplines:
  Collaborate closely with data scientists and ML engineers to integrate models into production‑grade products, and with product managers to shape roadmaps based on technical feasibility and user value.
• Dev Ops & CI/CD:
  Support cloud‑native deployment pipelines, automated testing, and observability for everything we build.
• Champion software engineering excellence:
  Drive continuous improvement across software engineering culture, codebases, and development practices.

• Clear communicator, with the ability to engage and influence both technical and non‑technical audiences.
• Experience in software engineering, with a focus on full‑stack product development in cloud environments (Azure preferred).
• Demonstrated success building and scaling production systems with global reach and multi‑region deployment.
• Strong proficiency and current experience in React, Typescript, Python and database systems (SQL + No
  
  SQL).
• Experience with performance monitoring and logging tools, including Cloud Watch, Sentry, or Data Dog, to ensure application stability, performance optimisation, and effective issue resolution.
• Experience managing or mentoring engineering teams, including cross‑functional collaboration.
• Understanding of secure architecture, API design, and performance optimisation.
• Experience with modern Dev Ops practices including CI/CD, containerisation (Docker, Kubernetes), and infrastructure as code (Terraform).

• Build purposeful, high‑impact products that help solve real‑world infrastructure, environmental, and societal…