oscope is a local-first OpenTelemetry explorer whose entire storage layer is chDB in the same process: OTLP/HTTP on 127.0.0.1, ClickStack-shaped span/log/metric tables, a zero-JS viewer, Arrow and Parquet export. Clojure, over libchdb.
- Good CI split: pytest runs the whole suite on embedded chDB in GitHub Actions, so verifying the schema needs no ClickHouse Cloud account. The live deploy flips to Cloud through env vars only - one schema file, one dialect.
- chDB allows one embedded server per process. Handled well here: the Session is a process-level singleton, so a second backend hands back the same engine instead of failing mid test run. 99 tests, ASOF joins included, no server.
- 6.8M bank-statement rows are unreviewable. 1,832 regexes are a to-do list. This console loads the corpus into a persistent chDB MergeTree, then scores each regex by how often its 30 output fields come back non-empty. Broken patterns surface as gaps.
