Part 14
Glossary
Version control and collaboration
- Repository (repo)
- the versioned project.
- Commit
- a dated snapshot of a set of changes, with a message.
- Branch
- a parallel line of work. Main is the production line.
- Remote / origin
- the reference copy hosted online.
- Push / pull
- send your commits up / pull others' down.
- Clone
- copy a repo to your machine.
- Merge
- fold one branch into another.
- Pull request (PR)
- a request to merge, usually reviewed first.
- Code review
- a peer (or the AI) re-reading before merge.
- Working tree
- the state of your files locally, committed or not.
Deployment and infrastructure
- Build
- compile and prepare the shippable files.
- Deploy
- publish the build, make it live.
- Rollback
- return to the previous version.
- CI/CD
- automation of build, then tests, then deploy.
- Pipeline
- the chain of automated steps.
- Gate
- an automatic check that can block the line.
- Environment
- local, preprod/staging, production.
- Env var
- a config value that changes per environment.
- Secret
- a sensitive value (a key), never in version control.
- Cache
- a saved copy served for speed. Purge it after some deploys or you serve the old version.
- CDN
- a network that serves content fast from cached copies.
- Preview URL
- a test URL generated for a branch before production.
Backend and data
- API
- the interface used to talk to the backend.
- Endpoint
- a URL plus a method (e.g. a create-event call).
- Auth / token
- proving who you are with a signed token, checked by the server.
- Webhook
- an incoming call a third party makes to you on an event.
- Schema
- the structure of the database (tables, columns, relations).
- Migration
- a versioned change to the schema.
- Row-level security
- access rules enforced per row, so the frontend can't read what it shouldn't.
- Full-access key vs public key
- the powerful key (server-side only) and the restricted key (safe for the frontend).
- Rate limiting
- capping requests per period to prevent abuse.
- Idempotence
- the same operation twice, one effect.
- Encryption
- protecting sensitive data at rest.
- Cron
- a task that runs on a schedule.
Frontend
- Component
- a reusable block of interface.
- State (of a screen)
- loading, empty, error, success. Handle all four.
- Design token
- a named style variable (color, spacing, type).
- Feature flag
- a switch that shows or hides a feature per environment. Off by default means not rendered, not just disabled.
- Optimistic UI
- updating the screen immediately, before the server confirms.
Tests and quality
- Type-check
- verifying the shapes of data before anything runs.
- Lint
- checking style and quality rules.
- Unit test
- verifying one function in isolation.
- End-to-end test
- simulating a full user journey.
- Smoke test / sanity check
- a quick real-conditions check after deploy.
- QA
- quality assurance, often a manual checklist before a release.
- Regression
- something that used to work and now doesn't.
- False green / false red
- a check that passes when it shouldn't / fails when nothing is wrong.
- Invariant
- a fact that must hold, used to prove a mass change.
- Hotfix
- an urgent fix pushed fast.
Security, operations, and cost
- Least privilege
- grant the smallest permissions that do the job. A leak's blast radius equals the privilege you gave.
- PII (personal data)
- anything that identifies a person. Collect the minimum, protect it, be able to delete it.
- OAuth
- a standard way to let a user grant limited access without sharing their password.
- HTTPS
- encrypted transport. Everything, always.
- Observability
- logs, error tracking, and alerting, so you learn about a problem from a dashboard, not a user.
- Error tracking
- a service that captures crashes with their context.
- Alerting
- a signal that reaches you when a key number goes wrong.
- Incident
- something broke in production; the plan is stop the bleeding, diagnose, fix forward.
- Semver (semantic versioning)
- major.minor.patch, signaling how big a change is.
- Changelog
- the dated, human-readable list of what shipped.
- Lockfile
- the file that pins exact dependency versions for reproducible builds.
- Monorepo vs multi-repo
- one repository holding several projects, vs several separate repositories.
- Staging
- a preprod environment that mirrors production for a final check.
- Unit economics
- what one unit of usage costs you to deliver, vs what you charge for it.
Building with AI
- Prompt
- the instruction you give the AI.
- Grounding
- the AI reading the existing code before it acts.
- Agent / sub-agent
- an AI working autonomously on a task, and explorers run in parallel.
- Spec (design doc)
- the document that fixes the scope and the decisions.
- Wave
- a small, testable, shippable unit of work.
- LLM
- the large language model that generates.
- Token (AI)
- the unit of text an LLM reads and writes, and the basis of AI billing.
- Standing instructions
- the house rules repeated in every prompt.