Ilya Ruderman: Circular is a geometric sans serif designed by Laurenz Brunner, author of the widely popular Akkurat. There are plenty of interesting references within Circular: for example, the а sounds a lot like Helvetica in its S-ness character — while at the same time, when it comes to all the other parameters, that is an absolute geometric sans: a circular O, etc. Brunner has carefully reviewed a whole bunch of sans typefaces popular in Europe — Futura as well as Kabel, and less known typefaces such as, for example, Erbar and Neuzeit. And all those somehow landed in the Circular’s DNA.
That is a highly popular typeface which is, in one way or another, used by many large market players — such as Spotify, or Airbnb. Lots of key brands built their identities upon some version (or sub-version) of Circular.
The typeface itself has since then grown into a huge project. Currently, just like any popular font, it supports Greek, Hebrew, Arabic, Vietnamese, Devanagari — pretty complicated writing systems. It was easy to design its Cyrillic. That is actually always a pleasure to work with Swiss guys — they deploy very simple, very clear, very logical solutions in whatever they do.