# DevOps — First Principles

## 1. The Principles

### P1. Reproducibility
Any environment can be rebuilt from source. Configuration is
declarative and versioned.

### P2. Automation
Manual steps are bugs waiting to happen. Everything is scripted,
testable, repeatable.

### P3. Observability
You cannot operate what you cannot see. Logs, metrics, and traces
are first-class.

### P4. Rollback First
Every deploy has a known-good rollback path. Rollback is rehearsed,
not improvised.

### P5. Progressive Delivery
Changes go out gradually — canary, blue-green, feature flags.
Big-bang deploys are for prototypes.

### P6. Configuration as Code
No snowflake servers. No "this one is different". Configuration is
in the repo.

### P7. Immutability
Build once, deploy many. Artifacts are immutable. Servers are not
mutated in place.

### P8. Security at Every Layer
Scanning, signing, SBOM, and supply chain integrity are part of the
pipeline, not bolt-ons.

### P9. Documentation in the Pipeline
The pipeline is the documentation. Reading the pipeline tells you
how the system ships.

### P10. Failure as Expected
Design for the failure mode, not the happy path. Chaos engineering
is a discipline.