Engineering

ENGINEERING The math behind our sampling-error bounds for approximate summarize When HelixQL samples instead of scanning everything, how far off can the answer be? We publish the error bound, not... Arjun Mehta · Jul 8 ENGINEERING Profiling data as a fourth signal: storing stack traces as flame-graph deltas Continuous profiling produces a full stack sample every 10ms per core. Storing each one independently would be absurd... Lena Park · Jul 2 ENGINEERING Backpressure: what happens when ingestion outruns compaction A sustained ingest spike can outpace background compaction. Helix has to decide who slows down first, and it's a... Priya Raman · Jun 30 ENGINEERING How HelixQL resolves by clauses into group keys A 'summarize... by' clause looks simple in HelixQL syntax, but resolving it against dynamic labels, computed... Arjun Mehta · Jun 23 ENGINEERING Cutting p95 by 40%: a checkout-api retro How trace-driven debugging found a retry storm behind a healthy-looking dashboard. Priya Raman · Jun 18 ENGINEERING Compressing high-cardinality label dictionaries with a shared vocabulary Two different metrics on the same pod share most of their label set. A per-metric dictionary wastes that overlap; a... Priya Raman · Jun 16