Amazon’s CEO has confirmed roughly 18,000 employees will be culled in the company’s biggest ever round of layoffs.

Teams working on hardware for Amazon’s Halo health tracker, Alexa, and Kindle were cut in the weeks before Christmas.

Andy Jassy originally signalled he would announce the extent of the remaining job cuts on January 18 after talking to employees unions. A leak by a disgruntled staffers forced him to make the announcement this morning.

“Today, I wanted to share the outcome of these further reviews, which is the difficult decision to eliminate additional roles,” he wrote.

“Between the reductions we made in November and the ones we’re sharing today, we plan to eliminate just over 18,000 roles.

“We typically wait to communicate about these outcomes until we can speak with the people who are directly impacted. However, because one of our teammates leaked this information externally, we decided it was better to share this news earlier so you can hear the details directly from me.”

The layoffs, once complete, will mark the biggest downsizing in the company’s 28-year history.

“As part of our annual operating planning review process, we always look at each of our businesses and what we believe we should change,” Amazon spokesperson Kelly Nantel said late last year.

“As we’ve gone through this, given the current macro-economic environment (as well as several years of rapid hiring), some teams are making adjustments, which in some cases means certain roles are no longer necessary.

“We don’t take these decisions lightly, and we are working to support any employees who may be affected.”