I am currently contributing to Prometheus Alertmanager. At present, I am working on adding support for Unicode (UTF-8) as part of a larger effort to adopt OpenTelemetry (OTel) in Prometheus. I have written a parser in Go, that replaces the existing regular expression parser, to enable parsing labels and label matchers containing UTF-8 code points. It eliminates all parsing ambiguities found in the existing parser while maximizing backwards compatibility. You can follow this work here.
For all my other contributions, you can find these here.