Why Elon Musk’s Twitter App Critique Missed the Real Performance Issues

Elon Musk sharply criticized the Twitter app for abusing RPC, claiming it performed over 1,000 batch RPC calls that slowed the app, and the criticism was rebuked by Twitter’s technical lead, who said Musk lacks technical understanding.

Eric Frohnhoefer, an engineer who has worked on the Twitter Android client for more than six years, also refuted Musk’s claim, stating that the reasons for the app’s slowness are unrelated to the alleged RPC issue.

A developer with over 20 years of experience suggested that Eric discuss the matter privately with Musk, but Musk responded with “He’s fired.” Eric later posted a photo of his locked development machine confirming his dismissal.

Another Twitter technical lead also announced being fired after posting a related tweet.

Eric explained that the Android client’s performance problems stem from three main factors: many rarely used features, years of accumulated technical debt that sacrificed speed, and long network response times. He urged a major refactor to address over a decade of technical debt and to remove unused functionality.

Musk’s cited 1,000+ batch RPCs occur on the server side and are unrelated to client requests. Twitter uses GraphQL to resolve requests across microservices, and a diagram was provided illustrating the relationship between client, server, request counts, and microservices.