Are you familiar with VictoriaMetrics?

Can you elaborate on how it is similar and dissimilar to Clickhouse?

What specific techniques are the same?

The core storage engine borrows heavily from it - I'll attempt to summarize and apologies for any errors, it's been a while since I worked with VictoriaMetrics or ClickHouse.

Basically data is stored in sorted "runs". Appending is cheap because you just create a new run. You have a background "merge" operation that coalesces runs into larger runs periodically, amortizing write costs. Reads are very efficient as long as you're doing range queries (very likely on a time-series database) as you need only linearly scan the portion of each run that contains your time range.