April Underwood is now Slack’s chief product officer

Former Twitter product lead April Underwood is getting another promotion this morning, now rising to the role of chief product officer of what aims to be the dead-simple employee communications platform Slack, according to Fortune.

Underwood previously served as director of product at Twitter, where she worked for five years before joining Slack as its head of platform. Shortly after that Underwood was promoted to the company’s VP of product, and will now serve as the company’s first chief product officer. These kinds of promotions imply some additional responsibility — especially as Slack looks to diversify and pitch itself as a more robust product than just a messenger — but also another point of maturation for Slack. The company hired its first chief financial officer, Allen Shim, in February this year.

Slack is one of those companies that faces a tense push-and-pull as it looks to get into larger and larger enterprises, which all have niche needs. The company is a darling in Silicon Valley thanks to its very simple interface, but with companies with thousands (or, eventually, tens of thousands of employees) just a tool with groups and direct messages could easily become unwieldy. That’s why Slack has invested in a variety of tools, including rolling out threaded messaging a little more than a year ago. Slack is likely one of those companies that gets hundreds of feature requests a year for larger businesses that have niche use cases, but it still has to demonstrate that it’s a simple product without hitting feature creep status.

Underwood getting more authority over that evolution (of which she was already a huge part, including the development of threaded messages) is another signal that the company is looking to tap her consumer background at Twitter to create some kind of middle ground between feeling like a satisfying consumer product while still operating as an enterprise tool. Slack is increasingly looking to apply machine learning to help employees get to answers right away, and it still has to take the same kind of care in rolling out new features that satisfy the needs of larger organizations without sacrificing that simplicity that made it a darling in the first place.

Slack most recently hit a $5.1 billion valuation in a recent investment round, and said it had around 6 million daily active users in September last year. That might be small-ish compared to the size and scale of Twitter, but as something geared toward internal communications at companies, that level of engagement in the workplace is going to increasingly be a selling point for the company as it looks to grow into that valuation.