About me

Hey, I'm Alex Harri.

I write about software engineering topics like TypeScript, performance, and mathematics. View blog.


As a very early employee at Taktikal—and subsequently as a Tech Lead—I built our first front-end applications, their supporting web services, and their CI/CD pipelines. That gave me valuable experience in building applications from scratch and maintaining them as they evolve. I worked at Taktikal for 4 years.

Over the past few years, I've transitioned to lower-level work developing and optimizing complex software where performance is critical.

At GRID, I worked on their JavaScript-based spreadsheet engine running in the browser, their formula parser written in Rust, and wrote some Python for the back-end. See "Making GRID's spreadsheet engine 10% faster".

In my current role at Arkio I've been working a lot with 3D geometry and math (see "Planes in 3D space"). Arkio is an architectural solid modeler running in VR headsets, written in C#. My work has mostly been on the core geometry layer and the editing tools (see "Introducing Arkio's Pin Tool").


I've written about topics ranging from performance and mathematics to TypeScript and monorepos.

My first really popular post was "The Engineering behind Figma's Vector Networks", which I wrote back in 2019. It's a lengthy post covering multiple topics, and it contains more than 200 diagrams and illustrations.

I've written three posts about TypeScript so far:

My first post containing interactive elements is "Multi-cursor code editing: An animated introduction", which uses animated instances of the VS code editor to demonstrate uses cases and techniques for multi-cursor code editing.

Another post containing a lot of interactivity is "Planes in 3D space". It contains over 50 interactive 3D illustrations, intended to provide a visual and intuitive understanding of planes.

I've also written about monorepos, performance (twice) , and bit manipulation.


My personal projects can be found on my GitHub page.

Notable project include an animation editor, a helper for Icelandic name declension called Beygla, an experimental schema builder called Strema, and this website.


You can contact me via a message on LinkedIn or by sending me an email (you can find my email address on my GitHub page).