Design a data center to deploy to Mars
Was asked this question for a L5 SWE role at Google. I don't work in data center ops, and the interview was for a software engineer role. My experience is in backend systems. How would one go about answering something like this? Clearly I have a lot to learn!
Plot twist: interviewer has upcoming interview at spacex and is fishing for ideas.
😂
i would do that
How would you work around really high latency?
That's a good point, I didn't consider that in my answer at all. My answer was more around logistics since the question was more about "deploying" the data center to mars, I missed the boat (space ship?) by a long shot.
The answer is quite simple. You would state at your not an expert at designing data center. Especially for a project as important as that would want someone with more expertise to design it. So you would hire experts to design it for you.
You must be a manager or TPM 😂
I'm not but that's a stupid question to ask a software engineer with no experience at all designing a data center or even knowing what a normal data center looks like. And that's probably the answer they are looking that your not an expert or don't know anything about it and are open to asking for help with other team members or some weird psycho analysis like that.
I was asked a question around something that's not my domain expertise during a interview at Okta. I answered that hey I'm not an expert at this. But I would reach out to X team members at the company and ask for help. And the interviewer was happy with my answer and acknowledged that it's the answer they were looking for and I was the only one who stated I would ask for help. While everyone started blabbing and making you answers.
There is no human presence on Mars yet . Any storage medium is a data center. All the rovers have hard drives . They are the datacenter.
How old are you?
What the fuck has that got to do with anything
Some troll PM would go about like this: there are some key questions I would like to ask. 1) what's the motivation for building a Dc on Mars? Cost? Local processing of data? 2) leads to ask, what will be the usage pattern? Is it process there and upload to planet Earth or is there continuous communication? 3) for any dc, there are 4 key things: power, cooling, the hardware, there's networking 4) two most viable systems for power, solar and nuclear. Based on how big we need. 5) we can try some tricks around cooling. Capturing the super cold night air could be a method 6) ...... Bluff like this 🤣🤣
Air density would be an issue for cooling. Even though the air is very cold, it might not cool your racks effectively.
Also MTTF for hardware.
I think the first question has gotta be why is there a data center being deployed to Mars. Like, did they want you to get into the logistics of getting the supplies for it there? How are you going to power the damn thing? What will connect to it? What is it supposed to service?
Sounds worthwhile. I’m into it.
How do you get the data from earth to Mars? What is the peak transfer rate? What do you do when the sun is blocking line of sight, relay off satellites? It would also take like 200 seconds to send a signal.
Delay is at max 21 minutes and minimum 3 minutes , ONE WAY.
True, I had a units error. It's like 200 seconds minimum.
Obviously interviewers at Google are bored.
May be. But this is my dream job, and I hope to get better at this in couple years when I re-interview. Blaming the interviewer is not a plausible solution for my situation, I'm better off introspecting how I could've done better. My recruiter told me that my performance on other areas were good except "system design" where I was asked this question. There is a chance HC may approve at a lower level but that's a huge step down from my current LinkedIn level (Staff SWE)
Here is my thoughts, it would be same as if you design any datacenter on Earth plus the delta between Earth and Mars. Open ended question is often asked to candidates to see if they are able to ask right question back to clarify the scope.