The Signal Path

Every production outage is debugged twice: once by the engineer, and once by the tools that were supposed to see it coming.

The Signal Path builds those tools from scratch. Across 302 pages and sixteen chapters you grow a single observability system — Lens — from a Go binary that reads /proc all the way to a multi-cluster platform with its own metrics store, tracer, anomaly detection and cost model. Metrics, logs and traces: the three pillars, built by hand so you understand exactly what every off-the-shelf agent is actually doing.

The path

1. The single agent — reading /proc, emitting the first metric
2. The first thousand metrics — a TSDB ring buffer from scratch
3. Logs are just events — structured logging and the label index
4. The agent grows — eBPF probes into the kernel
5. Traces and the span — a distributed tracer
6. The unified pipeline — an OpenTelemetry Collector clone
7. The three pillars — correlating metrics, logs and traces
8. Service maps — building the dependency graph
9. Anomaly detection — statistical models that flag the unusual
10. Root cause analysis — causal graphs through a failure
11. Predictive observability — forecasting before it breaks
12. The dashboard that thinks — an SLO and error-budget engine
13. The data lake — tiered storage at petabyte scale
14. Multi-cluster — federating queries across clouds
15. The cost of seeing — what observability actually costs, and how to cut it
16. The principles that remain — what stays true when the tools change

Each chapter introduces exactly one problem, explains why it happens, and shows the code that solves it — in Go and Python, with real frameworks and explicit trade-offs.

Companion code included. Sixteen chapter directories, each a complete, runnable program showing Lens as it stood at the end of that chapter. Free on GitHub: github.com/DjangoZenDev/signal-path

Formats: PDF and EPUB. Download immediately after purchase.