Unified Alerting in Grafana 8.0
Co-authored Alertmanager component and authored the notification channel pipeline of the Unified Alerting in Grafana 8.0. You can find my PRs here.
WAL in Ingesters (chunks based)
The ingesters used to lose data whenever they would crash as it held all the data in the memory. I took over Tom's initial PoC and got Write-Ahead-Log (WAL) into ingesters in PR#1103 which prevents data loss during crashes. Read more about it in this blog post.
In the process of massively scaling alertmanagers in Cortex, I implemented the distributor component for alertmanager in PR#3671 which shards and replicates the requests across alertmanagers.