Hey, I'm Sasha Koss,
Here's what I do:

I'm a Singapore-based product engineer with almost 20 years of experience building and shipping software products.

I'm well-versed in various technologies, from full-stack web and system development to machine learning and game dev. My main tools are Rust, TypeScript, and, if I have to, Python. I also design and manage products as well.

I created date-fns, a popular open-source project with 100M+ downloads per month. According to State of JS 2024 37% of all JavaScript developers regularly use date-fns.

My GitHub profile is probably the best place to see what I do.

Current Projects

At this moment I focus on Alumnium, an open-source SOTA end-to-end testing agent.

I'm also working on Genotype, a programming language that transpiles to idiomatic TypeScript/Rust/Python types.

Work History

Since 2017, I work independently, focusing on my own products. I created a Twitter management app Chirr App and bootstrapped it into a 100K ARR business. When Twitter became X and the app lost traction, I switched to trying out various AI product ideas (Daisy Chain, Mind Control and Mind Rig).

Before 2017, when I started my independent career, I worked at Toptal as a team lead, managing a team of ~10 engineers. I joined the company in 2012 as a front-end lead and helped the company grow from a handful of engineers to 150+ people strong.

Before 2012, I worked as front-end engineer at Evil Martians, a leading product development consultancy. I contributed to many project including Groupon.