Sasha Koss
Co-Founder at Chirr App
Singapore
Summary
🤩
RockstarSasha Koss is a serial indie maker and co-founder with 16 years of software experience, now building AI-first tooling from Singapore through startups like Mind Control and Daisy Chain AI. He bootsrapped multiple products (including Chirr App) and combines hands-on full-stack development with product instincts to ship lightweight, practical developer and creator-focused tools. An active open-source contributor, Sasha has improved widely used JavaScript and Ruby projects—contributing tests, shims, and features to projects such as Zepto, es5-shim, date-fns, and underscore.string. His work spans front-end finesse, back-end reliability, and localization/timezone-aware utilities, showing attention to edge cases and compatibility. Comfortable toggling between founder-level strategy and deep technical execution, he treats engineering as product discovery and maintains a playful commitment to open-source writing and experimentation. A subtle strength: he focuses on developer ergonomics and reproducibility—turning messy integrations into maintainable, testable libraries and tools.
16 years of coding experience
Stackoverflow
15,837reputation
2.6mreached
12answers
14questions
google-cloud-firestore
top-5%
Github Skills (35)
javascript10
strings10
s510
date-manipulation10
text-manipulation10
testing10
typescript10
ruby10
localization10
typescript-types10
js10
nodejs10
typescripts10
zepto10
ecmascript10
Programming languages (16)
Github contributions (5)
date-fns/date-fns
Oct 2014 - Jan 2023
⏳ Modern JavaScript date utility library ⌛️
Role in this project:
Back-end Developer & Localization Specialist
Back-end Developer & Localization SpecialistContributions:111 releases, 349 reviews, 821 commits in 8 years 5 months
Contributions summary:Sasha's contributions primarily involved the development of a modern JavaScript date utility library. This included implementing and testing core date functions like `addDays`, `isMatch` and also the integration of time zone support. The user also focused on localization, which suggests involvement in making the library accessible for multiple languages and regions. This includes implementation and testing of new locales.
date-fnsjavascriptnodejsmodern-javascriptutilities
esamattis/underscore.string
Jan 2011 - Apr 2012
String manipulation helpers for javascript
Role in this project:Full-stack Developer
Full-stack DeveloperContributions:20 commits in 1 year 3 months
Contributions summary:Sasha primarily contributed to the development and maintenance of a JavaScript string manipulation library. Their work involved significant changes to the project structure, including modifications to the minified distribution file and the test suite. They implemented new string manipulation functions and fixed an issue related to titleize function. The user also integrated the library with both Underscore.js and Node.js environments.
manipulationstringjavascriptstring-manipulationutility
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