CASSIDY WILLIAMS IS @CASSIDOO SENIOR DIRECTOR OF DEVELOPER ADVOCACY AT GITHUB 15,000+ NEWSLETTER SUBSCRIBERS AND COUNTING PRESENTED TO THE UNITED NATIONS AT AGE 22 WON A HACKATHON ON A TRANSATLANTIC FLIGHT GLAMOUR 35 WOMEN UNDER 35 CHANGING TECH BUILDER OF MECHANICAL KEYBOARDS & DEVELOPER COMMUNITIES LIFT AS YOU CLIMB CASSIDY WILLIAMS IS @CASSIDOO SENIOR DIRECTOR OF DEVELOPER ADVOCACY AT GITHUB 15,000+ NEWSLETTER SUBSCRIBERS AND COUNTING PRESENTED TO THE UNITED NATIONS AT AGE 22 WON A HACKATHON ON A TRANSATLANTIC FLIGHT GLAMOUR 35 WOMEN UNDER 35 CHANGING TECH BUILDER OF MECHANICAL KEYBOARDS & DEVELOPER COMMUNITIES LIFT AS YOU CLIMB
Cassidy Williams - portrait
PROFILE / ENGINEER & ADVOCATE

Cassidy
Williams

She makes memes, dreams, and software - in that order.

Software engineer. Developer advocate. Newsletter author. Mechanical keyboard designer. Career mentor. Meme-maker. Cassidy Williams has been building the web and the people who build it for well over a decade, and she's just getting started.

@CASSIDOO GITHUB SR. DIR. FRONTEND NEWSLETTER SPEAKER
@CASSIDOO EVERYWHERE
15K+
Newsletter Subscribers
10+
Years in Tech
50+
Conferences Spoken At
1
Scrabble Keyboard Designed

Cassidy Williams is the kind of person the internet was built for - and then she turned around and helped build the internet back. As Senior Director of Developer Advocacy at GitHub, she sits at the intersection of shipping real code and helping millions of developers do the same. Before GitHub, she ran through a catalog of roles that reads like a tour of tech's most interesting stops: Netlify, Remote, CodePen, Amazon, Clarifai, Venmo. Each one smaller and more energizing than the last, because Cassidy has always known she does her best work close to the code and close to the people.

She grew up in Downers Grove, Illinois, taught herself to build websites in eighth grade, and never really stopped. At Iowa State University she became the first woman to lead the computer science club, interned at Microsoft and Intuit, won a hackathon held on an actual transatlantic flight, and got herself invited to speak at the United Nations before she turned 23. The pattern was already clear: Cassidy Williams doesn't wait for permission.

"Lift as you climb: as you move up in the tech industry, lift people along with you." - Cassidy Williams

Based in Chicago with her family, Cassidy writes code, writes her weekly newsletter, builds mechanical keyboards, and occasionally builds entire video games for game jams. She describes herself as an introvert who reads as an extrovert - and there is something in that tension that explains a lot. The warmth is completely real. So is the preference to be left alone with a soldering iron and a good compile-time error.

Six Acts, Zero Gatekeeping

🏠
Origin Story
Downers Grove, Illinois. Eighth grade. One kid, one browser, zero patience for not knowing how things work. Cassidy Williams taught herself to build websites before high school started. The rest, as they say, was inevitable.
01
🎓
Iowa State
Computer Science at Iowa State University. First woman to lead the CS/SE club. Internships at Microsoft and Intuit. A hackathon win at 35,000 feet over the Atlantic. A speech at the United Nations. All before graduation.
02
🚀
The Company Tour
From Venmo to Clarifai, Amazon to CodePen (as its 8th employee), Netlify to Remote to Contenda - Cassidy chased interesting problems and interesting teams. She kept finding both. The common thread: developer experience and community, everywhere.
03
📨
The Newsletter
"rendezvous with cassidoo" launched as a modest mailing list and grew into a 15,000+ subscriber institution. Weekly coding challenges, developer news, bad jokes, and pictures of mechanical keyboards. A ritual for tens of thousands of developers every Sunday.
04
⌨️
The Keyboards
Cassidy doesn't just write about mechanical keyboards. She designs them. Her officially licensed Scrabble keycap set - built with Clackeys Inc. - shipped to enthusiasts around the world. A niche obsession turned tangible product. Very on-brand.
05
🐙
GitHub Era
As Senior Director of Developer Advocacy at GitHub, Cassidy shapes how millions of developers experience the platform. She writes for the GitHub Blog, speaks globally, advocates for TypeScript, GitHub Copilot, and the humans who ship the code.
06

The Engineer Who Gives It All Away

There is a certain kind of person in tech who accumulates knowledge the way others accumulate frequent flyer miles - obsessively, competitively, and always with an eye on the next tier. Cassidy Williams is not that person. Cassidy Williams is the person who notices you looking at the lounge map and quietly hands you a guest pass.

Her entire career reads like a deliberate rejection of the idea that knowledge is a competitive advantage. From the moment she stepped onto Iowa State's campus, she was running study groups, organizing hackathons, and dragging reluctant classmates toward the keyboard. The CS club presidency wasn't a resume line. It was a worldview in action. When the National Center for Women and Information Technology sent her to represent students at the White House Tech Inclusion Summit in 2014, she went to listen and to report back - not to be seen.

The United Nations speech came her senior year, part of a project to empower women in STEM. She was 21 or 22. She was terrified. She went anyway. This will become a recurring theme.

After graduation came the New York startup years, then the coast hop west, then the tour of companies that spans half a decade: Venmo (developer evangelist), Clarifai (lead developer evangelist), Amazon (where she ran developer voice programs and applied the company's famous "one-breath test" to Alexa skill design - if you can't say it in one breath, your response is too long). Each role was bigger or more prestigious than the one before it. She left each one for something smaller and more interesting.

"I've really learned that I like small companies," she said, after leaving Amazon for a role at CodePen as employee number eight. CodePen, for those unfamiliar, is the beloved browser-based code playground used by frontend developers worldwide. Being employee number eight at CodePen is the kind of thing that sounds casual until you realize what it means: you are building the thing, not just representing it. Cassidy was building.

The newsletter started as a low-key project. "rendezvous with cassidoo" - the name alone tells you something about how she operates. No LinkedIn-speak. No personal brand optimization. Just a weekly appointment between Cassidy and whoever shows up: a coding challenge, a roundup of what's cool in web development, a joke (often a bad one), and photos of mechanical keyboards. It grew from under 100 subscribers to over 15,000. The growth happened not because she optimized for it but because the product was genuinely, stubbornly, consistently good.

The mechanical keyboard thing deserves its own paragraph, because it perfectly illustrates how Cassidy Williams works. She didn't just get into keyboards as a consumer. She designed keycap sets. She shipped an officially licensed Scrabble keyboard set with Clackeys Inc. - actual physical products that left her hands and ended up under the fingers of enthusiasts across the world. She ran a Twitch series called "C+C Hacking Factory" with her sister Cami. She built Alexa skills on camera. She made things, and she made them publicly.

After stints at Netlify (Director of Developer Experience), Remote, and a brief CTO role at Contenda - an AI content platform - she landed at GitHub in the role of Senior Director of Developer Advocacy. The fit is almost too obvious. GitHub is where developers live. Cassidy has spent her career making that life better.

In early 2026, she published a piece on the GitHub Blog about AI pushing developers toward typed languages - specifically noting that TypeScript had become the most-used language on GitHub, growing by over a million contributors in a single year. She's been thinking about these patterns, watching the developer landscape shift, and writing about it with the clarity of someone who has been a working engineer through multiple waves of hype and genuine change.

She speaks everywhere: the Grace Hopper Celebration for Women in Computing, TEDx, Figma Config, Codemotion Madrid, Deep Dish Swift in Chicago, TechCamp Korea in Seoul. She speaks at universities. She speaks at conferences where she's the most junior person in the room and at conferences where she's the keynote. She does it because she believes your voice could inspire someone to take the next step - and she holds herself accountable to that belief.

Cassidy describes herself as an introvert. People who have seen her on stage find this hard to believe. People who understand introversion understand it completely. The energy she brings to a room is real. It also costs something. She's deliberate about replenishing it: building keyboards alone, playing music, hanging out with her family, making memes, writing her newsletter from whatever quiet corner she can find.

Her dream workspace is, characteristically, both specific and slightly absurd: a makerspace and arcade hybrid, with better lighting, a pinball machine, an arcade cabinet, a laser cutter, a 3D printer, and an upgraded gaming PC. It's the workspace of someone who wants to make things - all kinds of things - and who has enough self-knowledge to know exactly what fuels her. This is what a decade of "lift as you climb" looks like up close. Not a philosophy on a poster. A person in a room, building something, leaving the door open behind her.

From Downers Grove to the World Stage

~2008
Self-taught web builder in eighth grade, Downers Grove, Illinois. The browser becomes her sandbox.
2011-12
Internships at Microsoft and Intuit during Iowa State University studies.
2013
Becomes first woman president of Iowa State's CS/SE club.
2014
Selected by NCWIT to represent students at the White House Tech Inclusion Summit.
2015
Presents to the United Nations on women in STEM. Wins a hackathon at 35,000 feet over the Atlantic. Graduates Iowa State.
2016-17
Developer Evangelist at Venmo, then Lead Developer Evangelist at Clarifai.
2018
Developer Voice Programs Lead at Amazon - designs Alexa interactions using the "one-breath test."
2019
Joins CodePen as Senior Software Engineer - employee #8. Loves small teams. Stays.
2020
Director of Developer Experience at Netlify. Newsletter "rendezvous with cassidoo" gains momentum.
2021-22
Head of Developer Experience at Remote; then CTO at Contenda (AI content startup). Designs Scrabble keyboard set.
2023+
Senior Director of Developer Advocacy at GitHub. Newsletter surpasses 15,000 subscribers. Speaks globally. Builds, ships, lifts.
2026
Speaks at Codemotion Madrid, Deep Dish Swift Chicago, TechCamp Korea Seoul. Writes about TypeScript's rise to #1 on GitHub.

The Quotable Cassidy

Lift as you climb: as you move up in the tech industry, lift people along with you.
- Cassidy Williams, core philosophy
You get a lot by giving.
- Cassidy Williams
Your voice could inspire someone to take the next step.
- On speaking and sharing
I wouldn't be where I am today if it wasn't for the community around me.
- Cassidy Williams
Humanizing tech workers is a good thing to do in general.
- On developer advocacy and community
I basically want a makerspace/arcade around me.
- On her dream workspace

The Receipts

💄
Glamour "35 Women Under 35 Who Are Changing the Tech Industry" - one of the most cited honors in women-in-tech journalism.
🔗
LinkedIn Top Professionals 35 & Under - recognized by the platform that tracks professional momentum.
🏛️
Presented to the United Nations on empowering women in STEM while still a senior in college. Before most people her age had a LinkedIn.
🏠
Represented students at the White House Tech Inclusion Summit, selected by the National Center for Women and Information Technology.
✈️
Won a hackathon conducted aboard a transatlantic flight from San Francisco to London. At altitude. Under pressure. With strangers.
📰
HuffPost "5 Inspiring Young Women Leading The Way In STEM" - early recognition that she was building something bigger than a job.
⌨️
Designed an officially licensed Scrabble mechanical keyboard keycap set with Clackeys Inc. - shipped to enthusiasts worldwide.
📨
Grew "rendezvous with cassidoo" newsletter from under 100 subscribers to 15,000+ through consistency and genuine care for readers.
🎓
First woman president of Iowa State University's Computer Science/Software Engineering student club - set a precedent that stuck.

Things You Should Know

🌐
She is @cassidoo on GitHub, Twitter, Bluesky, CodePen, and basically everywhere. The handle commitment is total.
💿
Her custom-built PC still has a CD drive in it. She put it there intentionally. No further explanation has been offered or is needed.
🎮
Built a game called Code Wave for the GitHub Game Off 2025. A developer advocate who codes games for fun. Extremely on-brand.
🎵
Has played music and was part of bands in Seattle. The creative output is not limited to screens and keyboards (though it does include keyboards).
📺
Co-hosted "C+C Hacking Factory" on Twitch with her sister Cami, building Amazon Alexa skills live on camera. Sibling content. Before it was a thing.
🤖
Used GitHub Copilot CLI to automate her Elgato studio lights. Then wrote a blog post about it. Dev advocacy as a way of life.
🎯
Uses Vimcal for her calendar and vim alongside VSCode. A person of taste and velocity.
🏠
Dream home office includes a pinball machine, arcade cabinet, laser cutter, and 3D printer. Not a metaphor. An actual specification.
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