Principal Full Stack Engineer

Mott MacDonald; City Of London; Hybrid; GBP 70,000 - 90,000; Full time

Job summary

A global engineering consultancy in London is seeking a Principal Full Stack Engineer to lead the design and development of AI-powered digital products. This role combines technical leadership with mentoring, requiring expertise in full-stack application development, cloud environments, and collaboration with cross-functional teams. The ideal candidate will have deep technical skills in React, TypeScript, and Python, along with experience in modern DevOps practices and scaling production systems globally.

Benefits

Private medical insurance

Flexible health benefits

Pension contributions matching

Generous holiday entitlement

Qualifications

• Ability to engage and influence technical and non-technical audiences.
• Experience in cloud environments, preferably Azure.
• Success building and scaling production systems globally.
• Strong proficiency in React, TypeScript, Python, and databases.
• Experience with performance monitoring tools.
• Experience managing or mentoring teams.

Responsibilities

• Design, build and maintain robust, secure full-stack applications.
• Take end-to-end ownership of digital product initiatives.
• Support the growth of a small team of engineers.
• Contribute to system architecture decisions.
• Collaborate with data scientists and ML engineers.
• Support cloud-native deployment pipelines.

Skills

Clear communicator

Full-stack product development

React

TypeScript

Python

Database systems (SQL + NoSQL)

Performance monitoring tools

Mentoring engineering teams

DevOps practices

Tools

Docker

Kubernetes

Terraform

Job description

Overview

Mott MacDonald is a global engineering, management, and development consultancy with over 20,000 employees across more than 50 countries and 140+ offices. We work across global industries, delivering exciting work that defines our future and makes a societal impact in the communities we serve. Our people power our performance – we succeed when they do. With opportunities to collaborate, learn, and grow, the possibilities for excellence are as varied as every individual. We are an employee-owned business, investing in creating a space for everyone to feel empowered, included, and valued. Whatever your ambition, Mott MacDonald is where people come to be brilliant.

Location: London

Recruiter contact: Nikki George

About the business unit

Mott MacDonald’s support services enable the organisation to run efficiently and effectively. The team offers specialist advice, best practice and technology to all areas of our business designed for our global reach.

About the Role

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.

What You’ll Do

• 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 MacDonald 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.
• DevOps & 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.

What You’ll Bring

• 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 + NoSQL).
• Experience with performance monitoring and logging tools, including CloudWatch, Sentry, or DataDog, 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 DevOps practices including CI/CD, containerisation (Docker, Kubernetes), and infrastructure as code (Terraform).

Why Join Us

• Build purposeful, high-impact products that help solve real-world infrastructure, environmental, and societal challenges.
• Be part of a mission-driven AI Solutions team that blends experimentation with delivery.
• Grow your leadership capabilities while remaining hands-on in a modern tech stack.
• Work with smart, collaborative colleagues who value clarity, pragmatism, and ownership.

We are actively recruiting a diverse workforce reflective of the communities we serve. We recognise that differences in ability, skills and experience are a strength and encourage applications from people of all backgrounds.

UK Immigration
Mott MacDonald Ltd. are not currently offering sponsorship to candidates under the Skilled Worker visa route in the UK. We welcome applications from candidates eligible for alternative immigration routes that do not require sponsorship.

Policy and Benefits

Agile working: We offer a hybrid working policy that supports well-being, flexibility, and trust.

Equality, diversity, and inclusion: We promote fair employment procedures and equal opportunities for all, fostering an inclusive environment.

Accessibility: If you need adjustments during the recruitment process, contact [e-mail].

Benefits include:

• Health and wellbeing: Private medical insurance, health cash plan, wellbeing program, and flexible health benefits.
• Financial wellbeing: Pension contributions matching, life assurance, income protection, flexible benefits, and annual bonus schemes.
• Lifestyle: Generous holiday entitlement, saving schemes, and discounts.
• Enhanced family and carers leave: Maternity/adoption leave, shared parental leave, and caring leave.
• Learning and development: Professional subscription and opportunities to develop skills through mentoring and training.
• Networks and community: Employee networks and community impact opportunities.

Apply now or for more information about our application process, click here.