Principal Mechanical Critical Systems Engineer

Cundall Johnston & Partners LLP; Greater London; On-site; GBP 55,000 - 75,000; Full time

Job summary

Cundall Johnston & Partners LLP is seeking an experienced Principal Engineer to join their data centre team in Greater London. The role requires expertise in mechanical design and consulting, with a focus on high-profile data centre projects.

As a Principal Engineer, you will lead project delivery, shape technical strategies, and contribute to the development of junior engineers. No prior data centre experience is required as you will receive extensive training through their internal DC101 programme.

Qualifications

• Experienced in delivering mechanical design solutions.
• Knowledge of HVAC systems and public health services.
• Educated to a degree level in a relevant technical field.

Responsibilities

• Deliver mechanical design solutions including HVAC and ventilation.
• Produce technical specifications and project reports.
• Conduct site inspections to inform design development.
• Collaborate with multi-disciplinary teams on projects.

Skills

Mechanical design

Consulting experience

Problem-solving

Initiative

Collaboration

Education

Degree in Mechanical Engineering or related discipline

Job description

We’re looking for an experienced and client-focused Principal Engineer with mechanical design experience to join our data centre team.

You will have excellent mechanical design and consulting experience, ideally from a highly technical background. Your previous project experience will demonstrate an ability to transition into our data centre sector. You do not need previous data centre experience to apply. Our data centre specialist designers will mentor you as you enter our internal DC101 programme. This will give all new joiners the skills, context, and mentors to successfully transition into the sector and grow your career in this exciting industry.

You’ll play a leading role in some of the most high‑profile data centre projects in the world. As part of our collaborative, multi‑disciplinary team, you will drive the delivery of regional and global data centre projects. As part of the role, you’ll be engaging directly with clients, shaping technical strategies, as well as reviewing and developing designs for our projects. You’ll be trusted to take ownership of your work while being supported by a team of experienced engineers.

As a Principal, you’ll also support the development of junior engineers, as well as contribute to project planning and fee proposals. In a leading role, you’ll help bring your technical expertise to the market and shape the direction of our growing team.

Responsibilities

• Deliver accurate mechanical design solutions including HVAC air‑conditioning, chilled water, ventilation, equipment selections, public health, and building management services systems.
• Produce mechanical designs, including HVAC and public health and building management services systems.
• Prepare technical specifications, schedules, calculations, project reports, and supporting documentation.
• Conduct site inspections and surveys to inform design development.
• Develop detailed and coordinated design solutions in collaboration with multi‑disciplinary teams.
• Contribute to internal and external project meetings, providing mechanical expertise and updates.
• Assist with fee proposals and business development activities as required.
• Collaborate with colleagues across regional and international offices on project delivery.

The Skills

We’re looking for a qualified engineer educated to a degree level in Mechanical Engineering, Building Services Engineering, or a related technical discipline. You may be Chartered or working towards it, either way, we’ll support your career path.

You’ll have gained experience in a consulting engineering role and are now looking to take this into a new challenge with greater responsibility and impact. We value engineers who bring initiative, problem‑solving, and a collaborative mindset to their work.

You don’t need previous data centre experience. Our DC101 programme has been designed to provide in‑depth technical training alongside your projects to ensure new joiners can succeed in the industry. This programme has led to multiple award wins and nominations for talent development across the data centre sector.

We know that to be the best at what we do we need a diverse workforce underpinned by an inclusive culture. Creating environments where everyone can find joy doing their best work is also great for everyone. That’s why we positively welcome applications from people of all backgrounds and identities, and encourage, support, and celebrate the diverse voices of our people.