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John Carmack's arguments against building a custom XR OS at Meta

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520 points OlympicMarmoto | 4 comments | 29 Aug 25 16:45 UTC | HN request time: 0s | source
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tanvach ◴[29 Aug 25 17:51 UTC] No.45067273[source]▶
Was at Oculus post acquisition and can say that the whole XROS was an annoyance and distraction the core technology teams didn’t need. There were so many issues with multiple tech stacks that needed fixing first.

Mind you, this XROS idea came after Oculus reorged into FB proper. It felt to me like there were FB teams (or individuals) that wanted get on the ARVR train. Carmack was absolutely right, and after the reorg his influence slowly waned for the worse.

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1. dedup-com ◴[30 Aug 25 01:06 UTC] No.45071051[source]▶
Just a small bunch of XROS people came from FB proper (mostly managers) because an average FB SWE has no required skills. Most folks were hired from the industry at E5/E6 and I think we had ever took one or two bootcampers that ultimately were not successful and quickly moved elsewhere in FB.
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2. globnomulous ◴[31 Aug 25 20:43 UTC] No.45086899[source]▶
What were the required skills that bootcampers lacked? Has anybody without a university degree succeeded there?
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3. dedup-com ◴[31 Aug 25 21:17 UTC] No.45087179[source]▶
Knowledge of C (XROS was written in C and during the interviews the candidate rather uncommonly wasn't given a choice of programming language) and general understanding of how a computer works at a low level. Knowing the purpose of "volatile", understanding cache lines, mapping virtual memory to physical memory, DMA, this kind of thing.

I think everyone had a degree but looking at my degree (applied math) in particular nothing that I had learned at the uni was immediately useful and I think there isn't really anything that would prevent a smart person with a GED and some history of, say, Linux kernel contributions from succeeding on a team like this. Except may be a degree is needed for H1B visa for those who need it.

4. dedup-com ◴[31 Aug 25 21:47 UTC] No.45087402[source]▶
I just realized that you might not know what a "bootcamper" is. Facebook's hiring process generally goes like this:

- you're interviewed with a random team and evaluated if you'd be a good fit for the company.

- you are hired and go through a multi-week "bootcamp" to learn FB's vocabulary, processes, and tech stack, fixing some real bugs and implementing some real (but minor) features in the process.

- upon completing the bootcamp you seek a team that is of interest to you and if interest is mutual, you join the team. If you can't find a team after X weeks, you part ways with the company.