Principal Full Stack Engineer

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 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 MacDonald is where people come to be brilliant.
Location/s: LondonRecruiter contact: Nikki George


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 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 MacDonald is where people come to be brilliant.


About the business unit 
Mott MacDonald’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.


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 that is 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.

#LI-NG


UK Immigration
Mott MacDonald Ltd. are not currently offering sponsorship to candidates under the Skilled Worker visa route in the UK. This decision is as a consequence of the changes made to the Skilled Worker route by the UK Government in April 2024. We continue to welcome applications from candidates who are eligible for alternative immigration routes in the UK, that do not require sponsorship as a Skilled Worker now or in future.


Agile working
At Mott MacDonald, we believe it makes business sense for you and your manager to choose how you can work most effectively to meet your client, team, and personal commitments. We offer a hybrid working policy that embraces your well-being, flexibility, and trust.


Equality, diversity, and inclusion
We put equality, diversity, and inclusion at the heart of our business, seeking to promote fair employment procedures and practices to ensure equal opportunities for all. We encourage individual expression in our workplace and are committed to creating an inclusive environment where everyone feels they can contribute.


Accessibility
We want you to perform your best at every stage in the recruitment process. If you are disabled or need any support to enable you to apply or attend an interview, please contact us at [email protected] and we will talk to you about how we can support you.




We offer some fantastic benefits including:


Health and wellbeing
- Private medical insurance for all UK colleagues.
- Health cash plan to support you with every day health costs and treatments.
- Access to Peppy, providing free support from menopause experts for all UK colleagues.
- A variety of wellbeing support is available through our comprehensive wellbeing program, including access for you and your family.
- Ability to flex your salary to opt into a wide range of health benefits, many of which can be extended to your family too.




Financial wellbeing
- We match employee pension contributions between 4.5% and 7%.
- Life assurance equal up to 4 x your basic salary, with an option to increase the level of cover to 6 x your salary.
- Our income protection scheme provides a financial benefit, as well as absence and return to work support due to long-term illness or injury.
- Flexible benefits, including increased life assurance cover, critical illness insurance, payroll saving and will writing.
- As an independently owned business we share the financial success of the business with all our colleagues in various ways including annual bonus schemes.




Lifestyle
- A minimum of 33-35 days holiday each year, inclusive of public holidays and dependent on level, with the ability to buy or sell leave through our flexible benefits programme.
- Holiday entitlement increased to a minimum of 35 days after 5 years’ service.
- Variety of employee saving schemes and discounts from high-street retailers.




Enhanced family and carers leave
- Enhanced family leave policies, including 26 weeks paid maternity and adoption leave, and two weeks paid paternity/partner leave.
- Our shared parental leave matches maternity leave meaning we pay up to 24 weeks at full pay.
- Up to five additional days leave are provided for those with significant caring responsibilities, two of which are paid.




Learning and development
- Primary annual professional institution subscription.
- A broad range of opportunities to enhance both technical and soft skills through mentoring, formal training, and self-development options.




Networks, communities, and social outcomes
- Join a wide range of groups including our Advanced Employee Networks which support our LGBTQ+, gender, race and ethnicity, disability, and parents/carers communities.
- Make a difference within our communities through our social outcomes.


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

Proud member of the Disability Confident employer scheme

Disability Confident

About Disability Confident

A Disability Confident employer will generally offer an interview to any applicant that declares they have a disability and meets the minimum criteria for the job as defined by the employer. It is important to note that in certain recruitment situations such as high-volume, seasonal and high-peak times, the employer may wish to limit the overall numbers of interviews offered to both disabled people and non-disabled people. For more details please go to Disability Confident .