A little about me...

I'm a product designer and eternal optimist. Married to @Kmdleavens. Formerly @Yammer & @Cotap. I live in San Francisco, and tweet using @StephanCastro.


  • "Not bad!" – Linus Mixson
  • "Stephan is awesome to work with! He shines best when he's faced with hard problems. He demonstrated superior diplomacy and UI/UX mastery in a series of complex projects that we worked on together. He is an evangelist of UX research, and a skilled advocate of user-centric design. I strongly recommend him!" – Chris Pryor
  • "Stephan is among the best designers I've worked with. While at Cotap together, I was impressed that he doesn't consider his design work done until the product is shipped and working well. He was articulate in product design meetings, eager to embed himself with engineers to get details right, and great at iterating on designs after they shipped. I'd work with him again in a heartbeat." – Christian Niles
  • "As Senior Designer at Cotap, Stephan's tireless commitment to product design and design execution was deeply appreciated. His skills contributed in major areas of the product and brand since his very first day. I'd love to work together again in the future!" – Jason Lang

Where I've worked...

  • Product Design Contractor: Only a few months in! Check back for more info... (August 2019 to present)
  • Head of User Experience at Sense: Designer #1. Designed all new software products (iOS, Android & web) as well as building out the Product Design, Marketing Design, & User Research Teams. (February 2018 to August 2019)
  • Head of Design at Chorus.ai: Designer #1. Designed all new software products as well as building out the Product Design, Marketing Design, & User Research Teams. (July 2017 to February 2018)
  • Product Design Contractor: As a product designer for hire, I worked within San Francisco to help startups build out new features and meet important deadlines. Usually my role would include not only design work, but also consulting on how to properly grow a product team. (December 2015 to July 2017)
  • Senior Design at Cotap: During my time at Cotap I designed the iOS, Android, web, Mac, and iPad apps from scratch. (February 2014 to December 2015)
  • UI Designer at Yammer: I worked on the Yammer iOS, iPad, Android, and web apps, as well as overseeing the design integration with O365 during the Microsoft acquisition. (November 2012 to January 2014)
  • Freelancer: As a self-employed designer, I was able to work in various fields, increasing my knowledge base. (October 2011 to November 2012)
  • Creative Director for Cyclocross Magazine: As lead designer, I co-ordinated, budgeted, designed, and produced all the magazine, online, and marketing work. (January 2011 to November 2012)
  • Columbia Sportswear Company: Working with both the Equipment and SMU departments, I created and edited designs for various product lines. (July 2009 to December 2010)