Meet Cassidy Williams, Venmo’s 23-year-old developer evangelist

Cassidy Williams seems to have become a face for software engineers who are young women.

That role has taken her to the White House, earned her a spot in a feature-length documentary, put her on the USA Science & Engineering Festival’s Nifty Fifty list and even got her into Glamour magazine.
We met Williams at a Code As Craft event, just after she’d moved into her place in Downtown Brooklyn, which was just before she started her first job out of college, as a software engineer at financial services startup Venmo.

It hasn’t always been nice for Williams out there, though.
She’s taken a stand for women in the scene in the past, particularly at hackathons, and gotten a lot of (largely anonymous) hostility for it. After writing this simple but direct piece about the fact that college hackathons are professional events, people started to do strange things, like creating phony profiles for her on social media sites or comment-spamming everyone she knows about wanting to get in touch with her.
“If I keep quiet, then the trolls win, and there’s one less woman speaking out,” Williams told Technical.ly Brooklyn. “But if I keep talking, then I keep getting bothered by the trolls.”
For now it seems to have died down, she says. “It’s better that it happened to me than someone who’s newer in the field and might actually drop out,” Williams said.
Williams went to Iowa State where her sister followed two years later. You can’t talk to Williams for very long without her bringing up her younger sister. She’s also a software engineer who Williams hopes will move out to New York when she’s done with college. She’s visiting soon so they can put together a series of videos for O’Reilly on basic HTML and CSS.
Williams credits an adviser for all the internships she did through college. She told us that she didn’t go into college knowing how important they were, but her adviser challenged her to go to the career fair regardless. That led to her first internship.
By the time she left school, she had experience inside companies like Intuit and Microsoft. Williams came out of college with lots of job offers, but rather than go with a big company, she opted for her current employer, a relatively small startup in New York.
When she started at Venmo, she was doing more back-end work, implementing the banking API, Plaid. She also helped with user blocking.
“It was interesting because we had to consider all these different cases,” Williams said. “And all the places where they would need to be blocked.” For example, say you had exchanged money with someone you’d blocked. You wouldn’t want that payment to disappear from your history, but you would also not want their profile to be clickable.
Her fellow Venmo engineers have taught her to love Vim, a text editor with two modes that makes it fast and easy to code without a mouse. (For more on the social aspect of Venmo, check out this Reply All episode.)
While Williams is pushing herself to do some non-code related stuff on her personal time, she also wants to be in charge of something. She has been able to attain a relatively high profile for a 23-year-old. She’s gone, she said, from an environment where everyone pushed her take on leadership roles to one where she’s new again.
“When you’re an adult, it’s like you’re a freshman again,” Williams said. “You can be a go-getter and take on as many things as you can, but other people have more experience than you.”

We’re going to mentor so hard. #MHacks pic.twitter.com/S6g6abZlGd

— Venmo Developer (@venmodev) January 17, 2015

That said, she does have a leadership role in her company already: part of her job is serving as Venmo’s first and only developer evangelist.
Williams is focusing on building positive tech communities, speaking at three meetups a month, as well as working on behalf of the brand through social media.