Uber didn’t like Silicon Valley’s biggest chat apps — so it was forced to make its own

Uber has 14,000 employees, many of which are engineers, so it’s no surprise that the company that built one of the most ubiquitous ride sharing apps also built its own internal chat app after running into issues with existing chat apps on the market.

In a blog post Tuesday, members of the company’s Employee Productivity Tools team detailed the creation of uChat, the custom internal chat application that some of its employees have been using for the last year.

Uber was most recently using Atlassian’s HipChat for workplace communications (after ditching Slack), but the company began building a replacement two years ago after it felt neither could meet its needs.

Here are some of the key takeaways from Uber’s road to building uChat.

The new app needed to be able to handle 70,000 users at once

uChat is built on top of Mattermost, an open source alternative to Slack and Atlassian’s HipChat.

To ensure that the platform could handle existing and future growth at the company, the team put it under rigorous stress tests, with the initial goal of handling 70,000 users at once, and sending 80 to 200 messages per second. Uber mentions that it had run into glitches and reliability issues with past chat apps.

The final product can process tens of thousands of users and 1 million messages daily.

It helped that it looked familiar

Uber used to use HipChat and Slack, and Uber mentioned that one of the advantages of building its own chat app off of Mattermost was that its “client user interfaces were similar to those of chat applications popular among Uber employees.”

The screenshots show that uChat does closely resemble HipChat and Slack, two of the most popular on the market.

Uber uChat
Uber said it chose Mattermost in part because of its familiar client interface. Uber

Nearly 20,000 existing chat rooms were migrated from the old interface…

“To establish this confidence and make the transition to uChat as seamless as possible, we pre-provisioned all employees with accounts and migrated nearly 20,000 chat rooms so that employees would not have to recreate or re-join any of the rooms they previously worked in,” Uber said in the announcement.

…but that didn’t make employees any more eager to switch over

“One key lesson learned during our experience was that the level of planning and organizational alignment needed to turn down an incumbent chat application required far more buy-in and coordination with our users than we initially anticipated,” Uber said. “But by remaining transparent, accessible, and quick to deliver improvements, we established a foundation of good rapport with early adopters and, over time, transitioned the entire company.”