Senior Mechanical Engineer

DayOne; Lahti; On-site; EUR 48,000 - 65,000; Full time

Job summary

DayOne is building its flagship hyperscale data centre campus in Lahti, Finland. This Mechanical Engineer role focuses on maintaining and optimizing mechanical infrastructure to ensure uninterrupted operations at scale, including HVAC systems, chillers, cooling towers, pumps and compressors.

You will work with cross-functional teams to design, install, operate, and maintain essential mechanical systems, align with safety policies, and drive preventive maintenance to minimize downtime in a

Qualifications

• Degree in Mechanical Engineering or a related field.
• 3–5 years of experience in mechanical engineering, preferably within a data centre or critical infrastructure environment.
• Strong knowledge of mechanical infrastructure, including HVAC, chillers, cooling towers, pumps and compressors.
• Effective communication skills and the ability to work effectively with a multidisciplinary team.
• Proficiency in English, both written and spoken. Knowledge of Finnish is a plus.
• Ability to work in a fast-paced operational environment.

Responsibilities

• Assist in the design, installation, operation, and maintenance of mechanical systems within the data centres.
• Ensure all mechanical infrastructure, including HVAC systems, chillers, cooling towers, pumps and compressors, operates reliably and efficiently.
• Support the implementation and maintenance of mechanical safety policies, procedures, and best practices.
• Perform preventative and corrective maintenance activities, ensuring all mechanical equipment and systems are serviced according to company and manufacturer standards.
• Coordinate with vendors and contractors for mechanical maintenance and upgrade projects, ensuring minimal impact on operations.
• Implement preventive maintenance strategies to minimize downtime.

Skills

HVAC knowledge

Mechanical systems

Troubleshooting

Education

Degree in Mechanical Engineering

Job description

About DayOne Data Centers

DayOne Data Centers is a Singapore-headquartered global digital infrastructure platform that develops and operates next-generation data centers across Asia Pacific and Europe. Trusted by leading hyperscalers and businesses, the company engineers, builds, and operates high-capacity, AI-ready campuses with speed, scale, and reliability.

Job Summary

DayOne is building its flagship hyperscale data center campus in Lahti, on a former industrial site in Kiveriö. The campus is designed to use Finland’s naturally cool climate for free cooling, with air-cooled chillers that remove the need for freshwater cooling. Join the Lahti team early and help shape how a campus of this scale is built, commissioned, and run.

Mechanical Engineer

plays a crucial role in maintaining mechanical infrastructure and systems of our hyperscale data centres. This role ensures the continuous and efficient operation of mechanical systems, supporting both routine maintenance and emergency repairs.

Key Responsibilities

Mechanical System Management

• Assist in the design, installation, operation, and maintenance of mechanical systems within the data centres.
• Ensure all mechanical infrastructure, including HVAC systems, chillers, cooling towers, and fire suppression systems, operates reliably and efficiently.
• Support the implementation and maintenance of mechanical safety policies, procedures, and best practices.

Maintenance and Upgrades

• Perform preventative and corrective maintenance activities, ensuring all mechanical equipment and systems are serviced according to company and manufacturer standards.
• Coordinate with vendors and contractors for mechanical maintenance and upgrade projects, ensuring minimal impact on operations.
• Implement preventive maintenance strategies to minimize downtime.

Safety and Compliance:

• Adhere to all relevant health, safety, and environmental regulations, ensuring compliance with industry standards and best practices.
• Participate in safety audits and contribute to the continuous improvement of safety protocols within the data centre.

Technical Support and Troubleshooting

• Provide technical expertise and support for mechanical systems, including troubleshooting and resolving mechanical issues.
• Collaborate with other engineering and operations teams to ensure integrated and efficient system performance.

Strategic Initiatives:

• Support the Mechanical Engineering Manager and Critical Services Manager in developing and implementing strategic initiatives to enhance mechanical system performance and support business growth.

Team Collaboration

• Work closely with other engineers, technicians, and the Mechanical Engineering Manager to ensure seamless 24/7 operations.
• Participate in training and development programs to enhance personal and team capabilities.

What We’re Looking For

• Degree in Mechanical Engineering or a related field.
• 3-5 years of experience in mechanical engineering, preferably within a data centre or critical infrastructure environment.
• Strong knowledge of mechanical infrastructure, including HVAC, chillers, cooling towers, pumps and compressors, nd the ability to resolve complex mechanical challenges.
• Effective communication skills and the ability to work effectively with a multidisciplinary team.
• Proficiency in English, both written and spoken. Knowledge of Finnish is a plus.
• Ability to work in a fast-paced operational environment.
• Proactive, solutions-oriented mindset with high integrity and a collaborative working style.

Why Join DayOne?

• Be a part of a company scaling fast in a booming industry.
• Work on an international stage with global leaders.
• Shape your career in a culture that values curiosity, agility, and bold thinking.

DayOne is proud to be an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees.