Practical Threat Hunting: Detection Engineering and Detection-as-Code: 24 Hands-On Builds with Sigma, KQL, SPL, Git, Testing, and CI/CD

Turn successful threat hunts into reliable, testable detection products.

Practical Threat Hunting: Detection Engineering and Detection-as-Code takes readers through 24 cumulative builds covering the full detection lifecycle—from defining observable behavior and telemetry contracts to testing, deployment, measurement, and retirement.

Using four synthetic detection products, Grant Halden demonstrates how to:

• Write precise behavioral and data contracts
• Develop portable Sigma rules and native KQL and SPL implementations
• Build high-quality validation data and boundary test cases
• Use regression and mutation testing to expose weak logic
• Manage detection content with Git and code review
• Create CI/CD gates for security content
• Tune detections without erasing required matches
• Handle enrichment failures and degraded operating modes
• Package, promote, roll back, and monitor detections safely
• Measure precision, coverage, health, and lifecycle risk
• Use AI assistance while keeping evidence and engineering judgment in control

The book includes code, event records, expected outputs, decision tables, original diagrams, review exercises, and a reproducible companion repository. Examples use fictional telemetry and clearly distinguish local reference evidence from native platform validation.

Written for detection engineers, threat hunters, SOC analysts, security content developers, platform engineers, and technical leads who want detection quality to be visible, reviewable, and repeatable.