I used the Fastmail site today after a long time to change some setting and noticed the UI had been updated. Really liking the new look, great job to you and your team!

I was interested in what front-end library you guys were using so I did a bit of searching and found a twitter post about OvertureJS. I know this is kind of random, but I'd love to understand how you guys came to the decision to build a framework from scratch instead of relying on Angular/React. What kind of technical limitations did they have that you guys wished to tackle with Overture?