“Btw, I’d like to apologize for Twitter being super slow in many countries,” tweeted Musk. “App is doing >1000 poorly batched RPCs [remote procedure calls] just to render a home timeline!”
Twitter software engineer Eric Frohnhoefer replied, "I have spent ~6yrs working on Twitter for Android and can say this is wrong.“
Musk replied, “Then please correct me. What is the right number?”
Frohnhoefer said, “Zero. The apps don’t make RPC calls.”
Musk fired him.
there’s some more elaboration from the engineer (and others concurring) quoted in this summary, though it hasn’t been updated to include that Musk fired him:
Soon after, Twitter software engineer Eric Frohnhoefer decided to embark on a bit of career roulette. “I have spent ~6yrs working on Twitter for Android and can say this is wrong,” he posted.
Musk returned: “Then please correct me. What is the right number?”
But perhaps it was not the number of RPCs, or remote procedure calls, that was the issue at all.
Further on, Frohnhoefer pointed out that his team had “done a bunch of work to improve performance” and agreed there was “plenty of room for performance improvements on Android.” However, he added: “I don’t think the number of requests is the primary issue.”
“I think there are three reasons the app is slow. First it’s bloated with features that get little usage. Second, we have accumulated years of tech debt as we have traded velocity and features over perf. Third, we spend a lot of time waiting for network responses.
“Frankly we should probably prioritize some big rewrites to combat 10+ years of tech debt and make a call on deleting features aggressively.”
Asked again about the “right number” of RPCs, Frohnhoefer replied flatly: “Zero. The apps don’t make RPC calls.”
[…]
Responding to Musk’s original post, software engineer Ben Leib said: “As former tech lead for timelines infrastructure at Twitter, I can confidently say this man has no idea wtf he’s talking about.”
Sasha Solomon, staff software engineer and co-tech lead of the core API platform team at Twitter, waded in, referring to the dramatic number of job losses among the technical teams. “You did not just layoff almost all of infra and then make some sassy remark about how we do batching[?]”
“Like did you bother to even learn how GraphQL works[?],” she said, referring to the query language which provides an approach to requesting data over HTTP.
(14 November 2022)