What Happened
Around 6pm UTC, our monitors discovered some problems serving font CSS from helix-pages. Around 5am UTC they occurred so often that this incident was triggered.
How we fixed it
The root cause were some issues with the HTTP/2 client that fetches the fonts from TypeKit. After modifying the configuration of the HTTP/2 client, the issues didn’t occur anymore.
What's next?
We will investigate more deeply why this particular HTTP/2 issue occurred and will improve the robustness of the HTTP/2 client.