Commonwealth Fusion Systems

Engineer Interview Experience

April 30, 2025

Neutral ExperienceNo Offer

Process

I applied online.

The interview process was fairly simple and straightforward. They asked me a few questions about myself and why I was interested in the position. After the initial screening, they jumped into a technical interview focused on mechanical design fundamentals.

Questions

One key question involved choosing the appropriate weld for a T-joint—options included single fillet, double fillet, and double bevel groove weld. I now understand they were looking for awareness of penetration depth and when full penetration is required for structural integrity.

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Interview Statistics

The following metrics were computed from 6 interview experiences for the Commonwealth Fusion Systems Engineer role.

Success Rate

0%

Pass Rate

Commonwealth Fusion Systems's interview process for their Engineer roles is extremely selective, failing the vast majority of engineers.

Experience Rating

Positive33%

Neutral33%

Negative33%

Candidates reported having mixed feelings for Commonwealth Fusion Systems's Engineer interview process.

Commonwealth Fusion Systems Work Experiences

Awful management is tanking the company

Engineer • Current Employee

Pros: Most of the individual contributors/hourly employees are excellent people who are there for the mission of clean energy. And god bless the technicians & test operations team, who are basically carrying the company's progress right now, without much recognition.

Cons: Godawful company management and benefits, in every aspect/level. - RAISES CAPPED AT 2%. Even for the highest performers. - "Unlimited PTO (most people take 2-3 weeks)" --quote from onboarding document - No bonuses, for anything (performance, retention, signing) - Your salary offer WILL be disappointing; they are banking on applicants being too "mission driven" to care about competitive compensation - Shady practices from HR on the non-compete agreement. Unless you are specifically "fired without cause" (layoffs), YOU ARE NOT BOUND BY THE NONCOMPETE UNLESS THEY PAY YOU GARDEN LEAVE (6 MO. SALARY). Check the agreement you signed. HR will make it seem like you're bound by it no matter what. -CEO refuses to let go of technical decision-making and is slowing down/obstructing useful projects -Every team uses different standards and software because someone on that team came from a company that used that standard/software -Onboarding barely existent -Onsite cafe is NOT free, only mildly subsidised. Plus, bare-bones food options for folks working 3rd shift. -The decision-making of team-level managers and middle-management folks appears to be extremely personality-dependent/who shouts the loudest/who is the most conflict-avoidant. Then, that mess gets dumped onto ICs in the form of conflicting/constantly changing priorities & job security being dependent on who you're friends with.

Awful management is tanking the company

Engineer • Current Employee

Pros: Most of the individual contributors/hourly employees are excellent people who are there for the mission of clean energy. And god bless the technicians & test operations team, who are basically carrying the company's progress right now, without much recognition.

Cons: Godawful company management and benefits, in every aspect/level. - RAISES CAPPED AT 2%. Even for the highest performers. - "Unlimited PTO (most people take 2-3 weeks)" --quote from onboarding document - No bonuses, for anything (performance, retention, signing) - Your salary offer WILL be disappointing; they are banking on applicants being too "mission driven" to care about competitive compensation - Shady practices from HR on the non-compete agreement. Unless you are specifically "fired without cause" (layoffs), YOU ARE NOT BOUND BY THE NONCOMPETE UNLESS THEY PAY YOU GARDEN LEAVE (6 MO. SALARY). Check the agreement you signed. HR will make it seem like you're bound by it no matter what. -CEO refuses to let go of technical decision-making and is slowing down/obstructing useful projects -Every team uses different standards and software because someone on that team came from a company that used that standard/software -Onboarding barely existent -Onsite cafe is NOT free, only mildly subsidised. Plus, bare-bones food options for folks working 3rd shift. -The decision-making of team-level managers and middle-management folks appears to be extremely personality-dependent/who shouts the loudest/who is the most conflict-avoidant. Then, that mess gets dumped onto ICs in the form of conflicting/constantly changing priorities & job security being dependent on who you're friends with.

I can't imagine a better work enviornment

Engineer • Current Employee

Pros: CFS is truly an extraordinary place to work. The company has a friendly environment where no manager is ever closed off in an office. Managers are social with you, and are usually there for help and discussion. They view you as investments, and as a result devote significant resources to making you feel like you are welcome and have career advancement opportunities with them Your work rarely feels impactless, because we all know that our success would lead to a solution to the global energy crisis

Cons: There are very few parking spots on campus.

I can't imagine a better work enviornment

Engineer • Current Employee

Pros: CFS is truly an extraordinary place to work. The company has a friendly environment where no manager is ever closed off in an office. Managers are social with you, and are usually there for help and discussion. They view you as investments, and as a result devote significant resources to making you feel like you are welcome and have career advancement opportunities with them Your work rarely feels impactless, because we all know that our success would lead to a solution to the global energy crisis

Cons: There are very few parking spots on campus.

Fast, fun, be open to change

Engineer • Current Employee

Pros: -You have the resources you need to build your contribution. -You get to see results of your work quickly. -You have a real shot at making commercialized fusion energy a reality -You get to work with people from many different industries -Everybody cares deeply about the company goals

Cons: - Change happens often. While everyone has the same overarching goal, the strategies to get there are constantly evolving. - Whack-a-mole with the critical path. If you are on the critical path, you have infinite resources but also pressure from all sides.

Fast, fun, be open to change

Engineer • Current Employee

Pros: -You have the resources you need to build your contribution. -You get to see results of your work quickly. -You have a real shot at making commercialized fusion energy a reality -You get to work with people from many different industries -Everybody cares deeply about the company goals

Cons: - Change happens often. While everyone has the same overarching goal, the strategies to get there are constantly evolving. - Whack-a-mole with the critical path. If you are on the critical path, you have infinite resources but also pressure from all sides.

Awful management is tanking the company

Engineer • Current Employee

Pros: Most of the individual contributors/hourly employees are excellent people who are there for the mission of clean energy. And god bless the technicians & test operations team, who are basically carrying the company's progress right now, without much recognition.

Cons: Godawful company management and benefits, in every aspect/level. - RAISES CAPPED AT 2%. Even for the highest performers. - "Unlimited PTO (most people take 2-3 weeks)" --quote from onboarding document - No bonuses, for anything (performance, retention, signing) - Your salary offer WILL be disappointing; they are banking on applicants being too "mission driven" to care about competitive compensation - Shady practices from HR on the non-compete agreement. Unless you are specifically "fired without cause" (layoffs), YOU ARE NOT BOUND BY THE NONCOMPETE UNLESS THEY PAY YOU GARDEN LEAVE (6 MO. SALARY). Check the agreement you signed. HR will make it seem like you're bound by it no matter what. -CEO refuses to let go of technical decision-making and is slowing down/obstructing useful projects -Every team uses different standards and software because someone on that team came from a company that used that standard/software -Onboarding barely existent -Onsite cafe is NOT free, only mildly subsidised. Plus, bare-bones food options for folks working 3rd shift. -The decision-making of team-level managers and middle-management folks appears to be extremely personality-dependent/who shouts the loudest/who is the most conflict-avoidant. Then, that mess gets dumped onto ICs in the form of conflicting/constantly changing priorities & job security being dependent on who you're friends with.

2.0
Awful management is tanking the company
Engineer • Current Employee
Devens, MA
June 5, 2026
Pros: Most of the individual contributors/hourly employees are excellent people who are there for the mission of clean energy. And god bless the technicians & test operations team, who are basically carrying the company's progress right now, without much recognition.
Cons: Godawful company management and benefits, in every aspect/level. - RAISES CAPPED AT 2%. Even for the highest performers. - "Unlimited PTO (most people take 2-3 weeks)" --quote from onboarding document - No bonuses, for anything (performance, retention, signing) - Your salary offer WILL be disappointing; they are banking on applicants being too "mission driven" to care about competitive compensation - Shady practices from HR on the non-compete agreement. Unless you are specifically "fired without cause" (layoffs), YOU ARE NOT BOUND BY THE NONCOMPETE UNLESS THEY PAY YOU GARDEN LEAVE (6 MO. SALARY). Check the agreement you signed. HR will make it seem like you're bound by it no matter what. -CEO refuses to let go of technical decision-making and is slowing down/obstructing useful projects -Every team uses different standards and software because someone on that team came from a company that used that standard/software -Onboarding barely existent -Onsite cafe is NOT free, only mildly subsidised. Plus, bare-bones food options for folks working 3rd shift. -The decision-making of team-level managers and middle-management folks appears to be extremely personality-dependent/who shouts the loudest/who is the most conflict-avoidant. Then, that mess gets dumped onto ICs in the form of conflicting/constantly changing priorities & job security being dependent on who you're friends with.

I can't imagine a better work enviornment

Engineer • Current Employee

Pros: CFS is truly an extraordinary place to work. The company has a friendly environment where no manager is ever closed off in an office. Managers are social with you, and are usually there for help and discussion. They view you as investments, and as a result devote significant resources to making you feel like you are welcome and have career advancement opportunities with them Your work rarely feels impactless, because we all know that our success would lead to a solution to the global energy crisis

Cons: There are very few parking spots on campus.

5.0
I can't imagine a better work enviornment
Engineer • Current Employee
Devens, MA
March 26, 2025
Pros: CFS is truly an extraordinary place to work. The company has a friendly environment where no manager is ever closed off in an office. Managers are social with you, and are usually there for help and discussion. They view you as investments, and as a result devote significant resources to making you feel like you are welcome and have career advancement opportunities with them Your work rarely feels impactless, because we all know that our success would lead to a solution to the global energy crisis
Cons: There are very few parking spots on campus.

Fast, fun, be open to change

Engineer • Current Employee

Pros: -You have the resources you need to build your contribution. -You get to see results of your work quickly. -You have a real shot at making commercialized fusion energy a reality -You get to work with people from many different industries -Everybody cares deeply about the company goals

Cons: - Change happens often. While everyone has the same overarching goal, the strategies to get there are constantly evolving. - Whack-a-mole with the critical path. If you are on the critical path, you have infinite resources but also pressure from all sides.

5.0
Fast, fun, be open to change
Engineer • Current Employee
Devens, MA
March 12, 2025
Pros: -You have the resources you need to build your contribution. -You get to see results of your work quickly. -You have a real shot at making commercialized fusion energy a reality -You get to work with people from many different industries -Everybody cares deeply about the company goals
Cons: - Change happens often. While everyone has the same overarching goal, the strategies to get there are constantly evolving. - Whack-a-mole with the critical path. If you are on the critical path, you have infinite resources but also pressure from all sides.

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