Tess Rosania
Software Engineer at Sierra
San Francisco, California, United States
Summary
👤
Senior🎓
Top SchoolTess Rosania is a software engineer and seasoned product leader with 16 years of experience building consumer and collaboration products at scale, from Twitter timelines to Slack’s core messaging and shared channels. A founder and former CEO of Balsa (acquired by Airtable), she blends hands-on engineering, product strategy, and growth instincts to ship impactful features and companies. Now focused on building AI agents at Sierra, Tess sits at the intersection of cutting-edge research and real-world commercial needs in San Francisco. She contributes to open-source Ruby tooling—helping stabilize Mongoid’s associations and validations—demonstrating deep backend competence alongside product leadership. Known for scaling experiences for hundreds of millions of users and running hundreds of A/B tests early in her career, she pairs empirical experimentation with technical rigor. Collected, opportunistic, and future-focused, Tess frames AI as both a challenge and an immediate product opportunity.
16 years of coding experience
12 years of employment as a software developer
B.A., Computer Science, B.A., Computer Science at Dartmouth College
Stackoverflow
9,943reputation
1.9mreached
32answers
0questions
html
top-1%
javascript
top-5%
jquery
top-1%
Github Skills (19)
jquery10
validations10
associations10
rails10
validation10
mongodb-database10
ruby10
orm10
mongoid10
html10
mongodb10
ruby-on-rails10
javascript9
unit-testing8
substring6
Programming languages (11)
Github contributions (5)
mongodb/mongoid
May 2010 - Jul 2010
The Official Ruby Object Mapper for MongoDB
Role in this project:
Back-end Developer
Back-end DeveloperContributions:7 commits in 1 month
Contributions summary:Tess primarily contributed to fixing bugs and implementing features related to associations and validations within the Mongoid framework. They addressed issues with nested attributes, foreign key handling, and the `validates_uniqueness_of` validation. The user also focused on ensuring that associations are correctly established and managed through various scenarios including object construction.
ruby-on-railsruby-object-mapperrailsmongoidobject-mapper
tessro/go-mail
Jul 2014 - Mar 2022
A robust RFC5322/2822/822 message parser
Contributions:105 commits, 2 PRs, 12 pushes in 7 years 9 months
message-parsermessagerfc5322parser
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