A female tech executive wrote a letter to working moms in a Fortune column on Tuesday that subsequently went viral.

"I’m sorry to all the mothers I used to work with," the letter written by Katharine Zaleski reads.

Zaleski is the president of PowerToFly, a New York startup that connects companies looking to hire female tech talent with women around the world that are qualified to work in tech positions at startups. Its clients include Hearst, BuzzFeed, and RebelMouse.

In the letter, the former manager for both the Washington Post and the Huffington Post says she regrets how she judged working mothers when she was younger. When her daughter Charlotte was born, Zaleski says, her whole mindset changed.

Her list of "infractions against mothers" includes questioning the "commitment" of a co-worker and mother who couldn't meet Zaleski for last-minute drinks; not disagreeing with another editor who suggested they "hurry up and fire another woman before she 'got pregnant'"; not speaking up when her male boss asked a potential hire who she was going to be able to make time for both her kids and her work; and scheduling last-minute, late-afternoon meetings, not realizing that working parents may have to leave to pick up their kids or be home when they got home from school.

"For mothers in the workplace, it’s death by a thousand cuts – and sometimes it’s other women holding the knives," Zaleski says in her letter.



"I wish I had known five years ago, as a young, childless manager, that mothers are the people you need on your team. There’s a saying that 'if you want something done then ask a busy person to do it.' That’s exactly why I like working with mothers now," Zaleski says. She goes on to apologize to the mothers who she used to work with.

Now, Zaleski is at PowerToFly, where she's able to make work a reality for moms around the world.

You can read her full column in Fortune here.