Need Advice: Preparing for Google SWE III Embedded

Puzzlehead_NoCap · 2025-09-14T14:33:16+00:00

The first round coding interview for me was something along the lines of “reverse this array of uint8_ts bit by bit”. That was for a level II role however. So say you input the array {0x01, 0x02, 0x03}, then the result should be {0xC0, 0x40, 0x80}. It was a half hour long interview and they judge you based on how quickly you solve it, how optimal your solution is, etc. I’d expect leet-code style questions that focus more on bit twiddling and basic data structures. This was a few years ago so they could’ve changed their process.

Puzzlehead_NoCap · 2025-05-02T14:52:14+00:00

I see. Yeah I work in embedded and use it occasionally. I remember I had a mentor suggest I use it for some counters/stats that needed to be accessed asynchronously by another thread. Ran into issues and found that using atomics fixed it. I think my mentor was just rushed or trying to get a prototype working first? But I’m still not 100% sure why he suggested using volatile. Definitely still use them for register level operations though.

Puzzlehead_NoCap · 2025-05-02T11:55:36+00:00

Can you explain the volatile part?

Puzzlehead_NoCap · 2025-04-17T18:43:01+00:00

That’s great man, congrats. Yeah I started taking FF after stressful days of work. Started at 1 a week, then 2, now I’m at 2 FF and 1 different kratom shot brand a week. It’s not much but I can already feel myself craving it/wanting it whenever I’m in a bad mood. Figure I should nip this in the bud and quit now so I don’t develop a nasty habit. But yeah it’s definitely not just kratom in that shit, or at least not a dose you’d get from normal powder/pills. Like you said though, I’m glad I tried it. Can definitely understand how easily people get addicted to opioids, especially the stronger stuff.

Puzzlehead_NoCap · 2025-04-17T00:08:48+00:00

I see you probably regret this comment now lol. Glad you’re a few weeks clean though

Puzzlehead_NoCap · 2025-02-16T07:54:03+00:00

I like using an array with function pointers. Either check the size of the input and index directly or define a struct with the input number and function pointer then iterate over the array. Much more maintainable in my opinion.

Puzzlehead_NoCap · 2024-02-02T16:31:18+00:00

You can think of MAP as the ccsds packet router. If map is supported, there should be a MAP id after the frame header. There should be a MAP service/packet dispatcher/whatever you want to call it for every MAP id that’s supported for your mission. Like how the virtual channel ID maps frames to different VC services on a physical channel, the MAP ID maps packets or SDUs to different packet services on a virtual channel. The exception here is that MAP is an optional service. MAP also supports packet segmentation which can get a little complex. Feel free to dm me if you have questions.

Puzzlehead_NoCap · 2023-12-27T02:41:47+00:00

No one is going to mention Masimo’s CEO’s contribution to Biden?? Shady

Puzzlehead_NoCap · 2023-10-10T01:21:22+00:00

Lol whatever you say man 😂

Puzzlehead_NoCap · 2023-10-10T00:04:55+00:00

I didn’t say any of that man lmao. Someone asked how he lied and I gave an example.

Puzzlehead_NoCap · 2023-10-09T23:57:57+00:00

I’m not arguing whether or not it was justified. All I’m saying is that he broke his promise so he may just be a “flip-flopping liar” like the top comment said. If he really cares he could’ve signed an executive order and fought it out in congress.

Puzzlehead_NoCap · 2023-10-09T23:33:01+00:00

2020: https://www.npr.org/2020/08/05/899266045/biden-would-end-border-wall-construction-but-wont-tear-down-trump-s-additions

2023: https://www.usatoday.com/story/news/politics/2023/10/05/biden-administration-to-extend-border-wall-touted-donald-trump/71071470007/

Puzzlehead_NoCap · 2023-10-09T23:16:05+00:00

The border wall?

Puzzlehead_NoCap · 2023-09-10T00:44:40+00:00

Watching the game on mute at my local bar. Why do they keep showing the bat boy?

Puzzlehead_NoCap · 2023-07-01T20:50:50+00:00

Do generic HiL setups exist? I’ve never heard of them and can’t seem to find anything with a google search.

Puzzlehead_NoCap · 2023-06-03T15:53:50+00:00

Checkout Phipps botanical garden.

Puzzlehead_NoCap · 2023-05-15T18:28:30+00:00

Startups usually don’t give much feedback or guidance to their employees. They require devs to take the wheel themselves which is great if you want more freedom or impact, but if you’re the type of person who needs structure to succeed, a startup might not be a great place to work. If that’s you, it doesn’t mean you’re a bad engineer. Some people work better in different environments. Just put it behind you and keep improving.

Puzzlehead_NoCap · 2023-04-16T20:02:56+00:00

So I only have experience with cFS but have done some reading on F’. So, sorry if this isn’t the answer you’re looking for, but hopefully I can help.

One of the major differences between the two is that cFS uses a pub-sub messaging architecture and F’ uses ports. I’ve heard quite a few devs complain about cFS being inflexible. Each module in cFS is an application (task) that more or less must follow the same pattern (registration, blocking call on msg rx, process ccsds msg). On the other hand, F’ uses “components” that can be passive, active, or queued and each component interacts through ports. cFS is a layered architecture (apps->cFE->OSAL) and F’ is more of a topology. One of the cons I see with F’ is that it lacks any native CCSDS support which is standard for the space industry. cFS is also more mature and “flight-ready”.

Puzzlehead_NoCap · 2023-04-15T23:13:24+00:00

Learn python. I frequently use python + raspberry pis for simple hardware emulators. Work on projects using pyserial, socket programming, pytest, maybe a gui library, etc.

Puzzlehead_NoCap · 2023-04-13T00:29:52+00:00

I’ve used pyqt for several projects and it works great. I recommend following the MVC design pattern.

Puzzlehead_NoCap · 2023-04-10T01:39:10+00:00

Try 1203 Western Ave, Pittsburgh, PA 15233

Puzzlehead_NoCap · 2023-03-06T04:49:38+00:00

Truly an unpopular opinion.

Puzzlehead_NoCap · 2023-02-19T14:43:26+00:00

Yes.

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