| ADR |
Architecture Decision Record: a short record of a decision, with context, alternatives, and consequences |
| Backlog |
A prioritized list of what hasn’t started yet |
| Branch protection |
Rules that block changes to main without a PR and green CI |
| CI/CD |
Continuous integration (checking every change) and continuous delivery (releasing in an automated way) |
| Conventional Commits |
A commit message convention with a type prefix (feat:, fix:) |
| Definition of done |
Criteria a task must meet to be considered finished |
| Deploy |
Releasing a version of the code to an environment |
| Docs-as-code |
Documentation versioned in the repository and reviewed like code |
| DORA |
Research that defined four delivery performance metrics |
| DR drill |
Disaster recovery rehearsal: actually restoring the backup, in a separate environment |
| Draft PR |
A pull request in draft: CI runs, but it can’t be merged and doesn’t request review |
| Epic |
A large body of work, split into features and tasks |
| Estimate (story points) |
A relative measure of a task’s size and uncertainty |
| Expand → migrate → contract |
A way to change the database without breaking the previous version of the code |
| Feature flag |
A switch that turns a feature on or off without a new deploy |
| GitHub Flow |
A flow with an always-deployable main and short branches through PRs |
| Iteration (sprint) |
A fixed work cycle; in this book, two weeks |
| Least privilege |
Each person has only the access their role requires |
| Observability |
The ability to understand the system through errors, logs, and metrics |
| Postmortem |
A blameless analysis of an incident, with improvement actions |
| Pull request (PR) |
A request to merge a branch into main, with a description, CI, and review |
| Rollback |
Going back to the previous version after a problematic deploy |
| RPO |
Recovery Point Objective: how much data it’s acceptable to lose in a disaster |
| RTO |
Recovery Time Objective: how long the service can be down in a disaster |
| Runbook |
A step-by-step guide for a known operational situation |
| SaaS |
Software as a Service: software used over the internet, maintained by whoever offers it |
| Secret scanning |
A GitHub feature that detects keys and passwords in commits |
| SEV |
An incident’s severity level (SEV1 is the most severe) |
| SOC 2 |
An audit of security controls, common for SaaS sold to businesses |
| Squash and merge |
A merge that combines all of a PR’s commits into a single commit on main |
| Staging |
An environment like production, with fictional data, for validating before release |