Principal Mechanical Engineer - Data CentresLocation: London, UK (Hybrid Working)Salary: Up to £100,000 + BenefitsVisa Sponsorship: Available if requiredJob Type: PermanentLead the Design of Next-Generation Data Centre InfrastructureA leading international engineering and design consultancy is seeking a Principal Mechanical Engineer to join its growing Data Centres team in London.This role offers the opportunity to lead the mechanical design of large-scale, mission-critical data centre facilities, supporting the infrastructure that powers global digital services and cloud computing. You will play a key role in delivering innovative, resilient, and energy-efficient mechanical systems for hyperscale and colocation data centre environments.As a Principal Mechanical Engineer, you will provide technical leadership across complex engineering projects, working closely with multidisciplinary teams to deliver high-performance building services solutions.Key ResponsibilitiesLead the mechanical design and technical delivery of data centre and mission-critical infrastructure projects.Develop HVAC and cooling strategies for high-density computing environments.Oversee the preparation of engineering calculations, technical specifications, drawings, and design documentation.Provide technical leadership and mentorship to engineers and project teams.Collaborate with multidisciplinary teams including electrical engineers, architects, sustainability specialists, and BIM teams.Act as a key technical interface with clients, contractors, and project stakeholders.Ensure designs meet performance, resilience, and sustainability requirements.Support project planning, risk management, and design coordination across multiple projects.Required Skills & ExperienceDegree in Mechanical Engineering, Building Services Engineering, or a related discipline.10+ years experience in mechanical design engineering within building services or consulting engineering.Strong expertise in HVAC systems, cooling plant, and mechanical infrastructure design.Experience leading complex building services or mission-critical engineering projects.Ability to guide and mentor engineering teams while managing technical deliverables.Experience producing and reviewing engineering calculations, reports, and design documentation.Proficiency with BIM and design tools such as Revit MEP.Strong client-facing and stakeholder management skills.Desirable ExperienceExperience delivering data centre or mission-critical infrastructure projects (preferred but not essential).Knowledge of data centre cooling systems such as chilled water systems, CRAH/CRAC units, or liquid cooling technologies.Experience designing energy-efficient or low-carbon building services solutions.Chartered Engineer (CEng) status with CIBSE or IMechE.What's On OfferSalary up to £100,000Visa sponsorship available for eligible candidatesHybrid and flexible working optionsOpportunity to work on large-scale global data centre projectsStructured career progression and leadership opportunitiesChartership and professional development supportCollaborative and innovative engineering culture