Chronosphere

Founded in 2019 by Martin Mao and Rob Skillington, who at Uber had built the open-source time-series database M3 to swallow the company's metrics firehose. Chronosphere targets cloud-native shops where Grafana dashboards over Kubernetes and microservices generate so many data points that observability itself becomes one of the larger bills.

The platform leans on controlling cardinality — letting teams see which metrics are actually used and cut the rest before they cost money. It's a direct jab at Datadog, whose per-metric pricing is often cited as the reason to switch.