Quality Assurance

Unit Testing

Test the smallest piece of logic in isolation, fast and deterministic.

Integration Testing

Test how multiple modules work together, including real databases and APIs where it matters.

End-to-End Testing

Drive a real browser through the full user journey, from login to checkout, against a deployed-like environment.

Contract Testing

Verify that a consumer's expectations and a provider's responses agree, without running the full integration.

Load Testing

Apply realistic and peak traffic to find the throughput ceiling and the first thing that breaks.

Mutation Testing

Automatically mutate the production code and check whether the test suite catches each mutation.

Snapshot Testing

Capture the rendered output of a component or serialized structure and fail on any unintended change.

Property-Based Testing

State a law the function must obey for all inputs, let the framework generate hundreds of random inputs to try to falsify it.

Test Pyramid

Balance the test suite: many fast unit tests, fewer integration, very few end-to-end.

Coverage Strategy

Use coverage as a map of untested risk, not as a percentage to maximize.

OWASP Top 10

Use the industry-standard list of the ten most critical web app risks as a baseline checklist.

Authentication & Authorization

Prove who the user is (authn) and decide what they may do (authz) — correctly, on every request.

Secret Management

Store, rotate, and deliver secrets (API keys, DB passwords, signing keys) without ever leaking them.

Dependency Scanning

Automatically find known vulnerabilities in your third-party dependencies on every change.

Static Analysis (SAST)

Scan source code for security patterns without running it — catch injection, auth flaws, and crypto misuse early.

Dynamic Analysis (DAST)

Scan the running application from the outside, probing for vulnerabilities a black-box attacker would find.

Penetration Testing

Have a skilled human attack the application like a real adversary, finding the chains automated tools miss.

Input Validation

Validate every byte of user input on the server before it touches your data or logic.

Cryptography Best Practices

Use cryptography correctly: the right algorithm, the right mode, the right key management — never roll your own.

Security Headers

Set the HTTP response headers that lock down the browser: CSP, HSTS, X-Frame-Options, and friends.

Core Web Vitals

Track Google's three user-centric metrics: LCP, INP, and CLS, and keep them in the 'good' range.

API Latency Optimization

Reduce the time from request to response, focusing on the p95 and p99, not the average.

Database Indexing

Add the right indexes for query patterns, and remove indexes that are never used or harm write performance.

Caching Strategy

Cache at the right layer (CDN, app, DB) with the right TTL and invalidation to avoid stale data and cache storms.

Bundle Size

Keep the JavaScript and CSS bundles small so the page loads fast, especially on mobile and slow networks.

Lazy Loading

Defer loading of below-the-fold content, images, and heavy components until the user needs them.

Performance Monitoring

Continuously measure performance in production to catch regressions before users notice.

Memory Leak Detection

Find and fix memory leaks where the application's memory grows unbounded over time, eventually crashing.

Performance Budget

Set limits on bundle size, image size, and request count, and enforce them in CI to prevent regressions.

Connection Pooling

Reuse database and HTTP connections instead of opening a new one per request, cutting latency and resource usage.

WCAG Checklist

Audit the app against the four WCAG principles: Perceivable, Operable, Understandable, Robust.

Keyboard Navigation

Every interactive element must be operable with the keyboard alone, with a visible focus indicator and logical order.

Screen Reader Support

Ensure the app is usable with screen readers (NVDA, JAWS, VoiceOver, TalkBack) by providing semantic HTML and ARIA.

Color Contrast

Ensure text and interactive elements have sufficient contrast against the background for low-vision users.

Focus Management

Move, trap, and restore focus for dynamic content so keyboard and screen reader users always know where they are.

ARIA Patterns

Use ARIA roles, states, and properties correctly for custom widgets that semantic HTML cannot express.

Accessibility Testing

Combine automated scans, manual keyboard testing, and screen reader testing to find a11y issues before users do.

Accessibility in CI

Automate a11y checks in the build pipeline so regressions are caught at the PR, not after launch.

Inclusive Design

Design for the full range of human diversity — ability, language, age, device, and context — from the start.

Review Checklist

Use a consistent checklist so every review covers the same ground: correctness, security, performance, readability, tests.

Review Comments

Write review comments that are specific, kind, and actionable, so the author can fix the issue without confusion.

Review Etiquette

Review promptly, respond to feedback gracefully, and keep the review focused on the code, not the person.

PR Size

Keep pull requests small and focused so they can be reviewed thoroughly in minutes, not skimmed in hours.

Review Tooling

Use tools (linters, type checkers, test coverage) to automate the mechanical checks so reviewers focus on logic.

Review Culture

Build a culture where review is a collaborative improvement, not a gatekeeping battle or a rubber stamp.

Pair Review

Review complex or high-risk changes together in real time, to catch design issues that async review misses.

Review Metrics

Track review cycle time, comment quality, and defect escape rate to improve the review process itself.

Review Automation

Automate the repetitive parts of review (lint, test, stale PRs) so reviewers focus on the parts that need human judgment.

Pipeline Design

Design the CI pipeline as a series of fast, independent gates that catch issues progressively from cheap to expensive.

Build Gates

Ensure the code compiles and builds in CI before it can merge, catching integration errors that local environments miss.

Test Gates

Run unit, integration, and e2e tests in CI as gates that block merge on failure, with coverage thresholds.

Required Status Checks & Branch Protection

Configure branch protection rules so the main branch can only accept changes after required CI checks pass, preventing broken or unreviewed code from landing.

Merge Queues for Serialized Integration

Use a merge queue to serialize PR merges so each PR is validated against the result of the previous merge, preventing the last-merge-fails cascade that breaks main.

Deployment Gates & Progressive Delivery

Insert approval and verification gates between build and production so a deployment is a deliberate, validated step — not an automatic consequence of a merge.

Concurrency Control & Pipeline Cancellation

Limit concurrent pipeline runs and cancel superseded runs so CI resources are spent on the latest commit, not on stale commits that will be pushed over.