Interface started out in late 2016 as an experiment to build a
perfectly pixel-fitting font at a specific small size. The
idea was that by crafting a font in a particular way, with a
particular coordinate system (Units Per EM), and for a particular
target rasterization size (11), it would be possible to get the
best of both sharpness and readability.

However after a few months of using an early version of Interface,
it dawned on everyone exposed to the test that this approach had
some serious real-world problems. Most notably that it was really
hard to read longer text. Because of the pixel-aligning nature of
that approach, the font took an almost mono-spaced appearance,
making it really easy to read numbers, punctuation and very short
words, but eye-straining to read anything longer.

The project was rebooted with a different approach, sticking with
the specific UPM, but crafting glyphs and kerning in a way that
made for more variation in the rhythm and smoother vertical and
horizontal stems.