Mechanical Engineer Interview Experience
September 20, 2022
Positive ExperienceNo Offer
Process
I applied online. The process took 4 weeks. It was just over one month from the time I applied to the time I finished the last interview, which was a panel interview. I applied for five engineering jobs and was emailed by a talent rep two days later. There was a phone call with them scheduled that same week, but on the day, the interview was postponed one more week. I had a video call with the project lead and was recommended for the video-call panel interview. The panel interview was scheduled for approximately 2 weeks later with multiple employees.
During the interview, I gave a 25-minute presentation to everyone about my career and projects, followed by two separate interviews:
- First interview: This was with high-level employees who asked me questions about very fundamental engineering concepts related to heat transfer, mechanical stress, etc., which were related to the job.
- Second interview: This was with a small engineering team that asked about my projects and sought to understand how I approach engineering problems.Ultimately it was a good experience, but the scheduling process seemed to be affected by the high number of positions they were hiring for. From my experience, it seemed that they were willing to bring me on board and I was a good fit for the team, until I pressed into the work-life balance.
From what I understand, as of my application, CFS is a company that is eager to deliver its first commercial products to the world, in order to aid humanity during a mounting energy-source crisis. To do this, they have adopted a "SpaceX" approach.My final thoughts are that CFS is an amazing company trying to crack an energy source that can benefit humanity in so many ways. If you want to help solve it, I'd say it's worth the effort to at least apply on the website. Be warned though, depending on your personal threshold for work, adept social engineering may be required as well. Remember, fusion is for the good of humanity, but you're a human too. Be wary of sacrificing yourself. Good luck.
Questions
For this feature on one of your projects, what would you do if you needed to make it lighter while retaining the same amount of strength?
Was this helpful?
Interview Statistics
The following metrics were computed from 6 interview experiences for the Commonwealth Fusion Systems Mechanical Engineer role.
Success Rate
17%
Pass Rate
Commonwealth Fusion Systems's interview process for their Mechanical Engineer roles is very selective, failing most engineers who go through it.
Experience Rating
Positive50%
Neutral33%
Negative17%
Candidates reported having very good feelings for Commonwealth Fusion Systems's Mechanical Engineer interview process.
Commonwealth Fusion Systems Work Experiences
5.0
Amazing place to work
Mechanical Engineer • Current Employee
Cambridge, MA
November 26, 2021
Pros: Lots of opportunity for learning and working on varied projects, good/fair compensation, friendly and hardworking coworkers, managers and company looking out for employees' best interests.
Cons: Very few cons. If this can even be called a con: An important project and lean team comes with a lot of responsibility and work. Be ready to work hard and balance multiple projects.
Not the most diverse workplace but the company is actively working to improve this. Note that fusion is historically not a very diverse field
5.0
Truly Rewarding Work at the Cutting Edge of Energy Innovation
Mechanical Engineer • Current Employee
Devens, MA
July 3, 2025
Pros: Working at Commonwealth Fusion Systems has been one of the most exciting and fulfilling experiences of my career.
It has been incredible to work to help prove / commercialize a new clean energy technology alongside some of the brightest minds in the world.
The work is not only technically challenging but also deeply meaningful and everyone is driven by the same ambitious goal.
What sets CFS apart is the culture of collaboration and innovation.
The team is diverse, passionate, and intellectually curious, and there’s a strong sense of shared purpose that drives everything we do.
Every day brings new learning opportunities, whether it’s through hands-on work with cutting-edge systems or cross-functional collaboration with experts from a wide range of disciplines.
Pros:
Extremely exciting and impactful work
Brilliant, diverse, and mission-driven colleagues
Opportunities to learn and grow in a fast-paced environment
Exposure to revolutionary technologies and real-world problem-solving
A strong sense of purpose and alignment across the company
Cons: Cons:
Some internal processes and structures are still evolving, which can occasionally lead to ambiguity or inefficiencies. However, this is understandable given the company’s rapid growth and ambitious goals.
5.0
A great place to work
Mechanical Engineer • Current Employee
Devens, MA
March 12, 2025
Pros: Intelligent, motivated, passionate team of coworkers who are working towards a singular goal. With many people working on getting SPARC designed and built, there are not major conflicting priorities or teams under cutting each other to look good at another's expense.
The company is transparent for how things are going across the board- progress towards goals, financial performance, hiring, discussing key issues, etc. They treat us like adults and communicate the good and the bad regularly via monthly team meetings, quarterly all hands meetings with open questions requested and honest answers given. It is refreshing.
Employees have a lot of latitude to explore and think outside the box and also have access to a vast array of in-house expertise to solve problems.
There is a new, objective, merit based performance review and stock/salary award program in place to reward performance.
Lots of opportunities to learn and grow through your daily work and interactions. It does help to be on site regularly, but hybrid and remote employees are still in the loop and as accessible and involved as anyone on site, for the most part.
The on-campus cafeteria is excellent- great variety, inexpensive, and healthy.
Shuttle from the Red line to Devens makes it possible to commute without having a car.
Onboarding is straight forward and well set up- this is the first job they were actually ready for me to start with a computer, badge, work space, swag, etc on day 1.
Cons: At over 1000 people spread across the US (and beyond), it's a big organization with a lot of layers, nuance, and tribal knowledge. It can be difficult at times to get to the right person for help, but this problem is solved by being on site frequently and being engaged with coworkers to develop the internal network.
We still have good startup vibes but are also experiencing inevitable growing pains with processes and systems so you have to rely on your immediate team and adjacent systems to keep you in the loop sometimes for things that may impact your work.
Parking is tight with shuttles to remote lots needed on the busiest days if you're not in early. It's not so convenient but it does work.
- 5.0Amazing place to workMechanical Engineer • Current EmployeeCambridge, MANovember 26, 2021Pros: Lots of opportunity for learning and working on varied projects, good/fair compensation, friendly and hardworking coworkers, managers and company looking out for employees' best interests.Cons: Very few cons. If this can even be called a con: An important project and lean team comes with a lot of responsibility and work. Be ready to work hard and balance multiple projects. Not the most diverse workplace but the company is actively working to improve this. Note that fusion is historically not a very diverse field
- 5.0Truly Rewarding Work at the Cutting Edge of Energy InnovationMechanical Engineer • Current EmployeeDevens, MAJuly 3, 2025Pros: Working at Commonwealth Fusion Systems has been one of the most exciting and fulfilling experiences of my career. It has been incredible to work to help prove / commercialize a new clean energy technology alongside some of the brightest minds in the world. The work is not only technically challenging but also deeply meaningful and everyone is driven by the same ambitious goal. What sets CFS apart is the culture of collaboration and innovation. The team is diverse, passionate, and intellectually curious, and there’s a strong sense of shared purpose that drives everything we do. Every day brings new learning opportunities, whether it’s through hands-on work with cutting-edge systems or cross-functional collaboration with experts from a wide range of disciplines. Pros: Extremely exciting and impactful work Brilliant, diverse, and mission-driven colleagues Opportunities to learn and grow in a fast-paced environment Exposure to revolutionary technologies and real-world problem-solving A strong sense of purpose and alignment across the companyCons: Cons: Some internal processes and structures are still evolving, which can occasionally lead to ambiguity or inefficiencies. However, this is understandable given the company’s rapid growth and ambitious goals.
- 5.0A great place to workMechanical Engineer • Current EmployeeDevens, MAMarch 12, 2025Pros: Intelligent, motivated, passionate team of coworkers who are working towards a singular goal. With many people working on getting SPARC designed and built, there are not major conflicting priorities or teams under cutting each other to look good at another's expense. The company is transparent for how things are going across the board- progress towards goals, financial performance, hiring, discussing key issues, etc. They treat us like adults and communicate the good and the bad regularly via monthly team meetings, quarterly all hands meetings with open questions requested and honest answers given. It is refreshing. Employees have a lot of latitude to explore and think outside the box and also have access to a vast array of in-house expertise to solve problems. There is a new, objective, merit based performance review and stock/salary award program in place to reward performance. Lots of opportunities to learn and grow through your daily work and interactions. It does help to be on site regularly, but hybrid and remote employees are still in the loop and as accessible and involved as anyone on site, for the most part. The on-campus cafeteria is excellent- great variety, inexpensive, and healthy. Shuttle from the Red line to Devens makes it possible to commute without having a car. Onboarding is straight forward and well set up- this is the first job they were actually ready for me to start with a computer, badge, work space, swag, etc on day 1.Cons: At over 1000 people spread across the US (and beyond), it's a big organization with a lot of layers, nuance, and tribal knowledge. It can be difficult at times to get to the right person for help, but this problem is solved by being on site frequently and being engaged with coworkers to develop the internal network. We still have good startup vibes but are also experiencing inevitable growing pains with processes and systems so you have to rely on your immediate team and adjacent systems to keep you in the loop sometimes for things that may impact your work. Parking is tight with shuttles to remote lots needed on the busiest days if you're not in early. It's not so convenient but it does work.
Explore Interview QuestionsTaro 75Google Interview QuestionsMeta Interview QuestionsAmazon Interview QuestionsApple Interview QuestionsNetflix Interview Questions
Explore Interview ExperiencesOpenAI Interview ExperiencesAnthropic Interview ExperiencesPerplexity Interview ExperiencesWindsurf Interview ExperiencesMistral AI Interview Experiences
