I think I’ve mentioned this in a previous blog, but ya I have summer internship at Facebook. A big part of it was probably my school, as there are a lot of other CMU rising juniors and seniors and graduate students here as well (all at the same start date for convenience), but I like to think part of it was also a good interview performance (what can I say i know some graph algorithms).

They had a whole team selection process, and probably because I put “comfort using Rust(lang) = high” on the sheet and had systems just below AI in terms of project preference, I was put on an infrastructure team working on a large Rust code base.

The Code

Ima wax poetic about how cool Rust is for a sec because this is my blog and I make the rules here. So: Rust is super cool holy cow.

• rustfmt makes sure no matter who writes the code, it all becomes readable at the end because everything from capitalization to spacing is opinionated.
• Builder patterns are encouraged by the language and safe to use and work pretty darn well as a result. If you don’t know what a builder pattern is, it’s basically something like

let foo = FooBuilder::new()
            .set_bar(5)
            .set_kaz(17)
            .build();

• The type system makes everything safe and even though you “fight” the compiler at times it’s really all about making you code better and I love the very descriptive and colorful error messages

Seriously if you have a project you’re considering doing in C or C++ due to performance reasons just use Rust you’ll thank me later.

Ok so back to Facebook: because the team is using Rust, and they didn’t quite expect an intern to have known Rust before the internship when they were drafting up the project plan, I breezed through the first few tasks and am now working on pretty real stuff that hopefully will be useful to other engineers there. Can’t divulge too much about the project specifics unfortunately but it’s fairly widely used internal app, I’m just adding more user-facing metrics to it.

At this point, I’m sort of in a Rust + SQL part of the project, and may even transfer over to Python + SQL once I need to use another certain internal framework. I haven’t actually used too much SQL before, but SQL Builder has been very nice to use in Rust, and the Presto Docs are surprisingly well-writen and informative. Sub-queries, GROUP BY, and FILTER(WHERE ...) are magic, query executors doin some crazy stuff to get those to be efficient with so much data.

Internal documentation alternates between “We have something from 2016 on it but it’s horribly out of date, just read the code (oh wait you don’t even know what the thing you’re looking for is called? sux to be u)” and “Everything is explained perfectly and has examples and test cases and is formatted well” which is hm so I’m glad I have a good manager. Which brings me to…

The People

With few execptions, everyone I’ve met at Facebook has been very nice and willing to help. My team and especially my manager + peers have been extremely helpful at answering my n00b questions at any hour of the workday and making me feel welcome and appreciated. Another great thing, what I also liked about CMU and TJHSST and what I should expect from most good tech companies, is that everyone is super smart. I like being surrounded by smart and hard-working people because that in energizing and I like both the environment and how it makes me a better person.

In some respects, I may have been lucky, because hearing from a few other interns (during optional organized “just get on a call and hang out with other interns in an unmonitored breakout room” that of course I’m going to go to) it seems not all the teams are this quality or they’re having trouble adapting to work and not getting enough support or they don’t really like the work they were assigned or whatever. I can get jazzed about lots of computer-related stuff and like to be sociable so that helps, but I’m still very glad I got the team I did.

TL;DR Facebook is a neat place with neat projects, still don’t know how much I agree with their ethics even with them trying to turn themselves around.