I applied online. The process took 3 weeks. I interviewed at Plethora in June 2016
Interview
I was applying to Plethora in June 2016. Whole communication took about 3 weeks.
First it was a call with HR, regular HR questions about my background and position role.
Second was a call with Computational Geometry Software Engineer, talking again about my background and the position, but more in depth on the technical end. It was an interesting discussion with an experienced engineer.
Third was a codding challenge that I could accomplish within 5 days. After sending my solution I got an answer that they were reviewing it. At the same time they asked me if I knew about the process of relocation from Germany to USA.
After that they never gave any comments on my solution, never answered my emails. That was really strange, it was negative experience.
I applied online. The process took 3 weeks. I interviewed at Plethora in Apr 2018
Interview
I applied online. The process took 2-3 weeks since I submitted my resume until I got an email with the sentence "After reviewing your work and experience, we've made the decision to not move forward at this time."
The process to coordinate interviews was very efficient. I had four phone interviews: one with a recruiter and three with technical people. They were nice during the interviews.
The interviews were easy: I had to explain my previous experience and answer technical questions about C++/STL, finite element method, and computational geometry. You do not need a specific training or preparation for the interviews.
I asked each interviewer about the pros and cons of the company. They did not mention any significant cons. They enumerated a lot of pros: benefits, impact of the work, work environment, etc.
Question to avoid (the interviewer was kind of embarrassed when answering the question). Some context: The main reason of Plethora's existence is the automation of CNC machining (the company is working hard on this, but still does not know when will be able to do it). I asked one of the interviewers about the difference with Protolabs, a competitor that has already automatized CNC machining. In addition, Protolabs also has an automatized service for on-demand manufacturing of parts using 3D-printing and injection molding. The interviewer told me Protolabs uses a pedestrian method that works but does not allow for very small tolerances. On the opposite, the method Plethora is developing will be more elegant and efficient, and will also allow for a better part finishing.
Personal opinion: If you have a MSc/PhD in Computer Science/Mathematics/Engineering, probably you are overqualified for the job.
Interview questions [1]
Question 1
- STL: difference between std::map and std::unordered_map.
- Dynamic allocation.
- Difference between passing by pointer and passing by reference.
- Explain the Finite Element Method.
- Explain how to measure the amount of material removed from an initial block to machine a specified part.
I applied online. The process took 8 weeks. I interviewed at Plethora (San Francisco, CA) in May 2016
Interview
First phone interview with HR person - regular HR questions and how I see a fit.
A simple challenge was given out to be finished within 5 days. I finished it in 3 and put in "extra credit" features. Found it on github before it was officially given out. My work on the challenge was never reviewed nor commented on.
Second and third phone interviews with engineering team - They seemed bright and came in with technical questions although answering these on the phone is always challenging. Forth phone interview with another HR person and seemed to be just a perquisite for "issuing" an onsite interview invitation.
Onsite interviews took the whole day : 6 interviews with 8 people. The engineering guys came first with technical questions. They seemed to overlook my non-quantitative background and %50 of the questions were beyond my training. The questions seemed to gauge knowledge as oppose to being able to build up on ideas. In my opinion, one can google anything nowadays so the barrier to knowledge is quite low – it’s the application and thought process that should be tested.
One of the engineering interviewers was very rude - texting during the interview while waiting for me to answer one of the questions.
Other onsite interviews were with "C-level" execs. They seemed to have a big vision and I generally had good discussions with them.
They probably had 30-some people on board when I interviewed so I eventually met 1/3 of the entire team over a 8 week period. I understand they are very careful who to hire (and all the employees' glassdoor posts advertise that), but I believe it was an overkill. By the end of the onsite interviews I was worn out and started doubting if it was a good fit. I expressed my concerns to the HR person mainly that the technical questions they asked did not match my background. They ended up not making an offer.
Interview questions [1]
Question 1
Meshing algorithms, performance through big O notations, computational geometry.