Deploy

Ship applications reliably with CI/CD, rollback strategies, and zero-downtime deployment patterns.

Security Scan

This skill is an instruction-only collection of deployment best-practices and is internally consistent with its stated purpose — it doesn't request credentials, install code, or perform actions itself.

Purpose & Capability

Name/description match the SKILL.md content: the file contains deployment checklists and strategies. Nothing in the metadata or instructions requires unrelated capabilities (no cloud credentials, binaries, or unusual config paths).

Instruction Scope

The instructions are prescriptive guidance (checklists and patterns) rather than runtime commands. They do not direct the agent to read local files, environment variables, or external endpoints beyond general recommendations, so the scope stays within deployment guidance.

Install Mechanism

There is no install spec and no code files. Because this is instruction-only, nothing will be written to disk or fetched during install.

Credentials

The skill declares no required environment variables or credentials. Mentions of secrets and target environment are advisory and do not imply the skill will request or access credentials.

Persistence & Privilege

The skill does not request always:true and uses default invocation settings. It doesn't attempt to modify agent config or persist credentials.

Assessment

This is a safe, read-only set of deployment best-practices (no code, no installs, no credentials). If you expected an automated deployer, note this skill is only guidance — an automated deploy skill would likely require cloud credentials, CLIs, or install steps. Always prefer skills from known sources when you need automation that will access infrastructure or secrets; such skills should clearly declare what credentials they need and what they will do with them.

Deployment Rules

Pre-Deploy Checklist

• Tests passing in CI — never deploy with failing tests
• Environment variables set in target — missing secrets cause silent failures
• Database migrations run before code deploy — new code expecting new schema fails
• Rollback plan ready — know exactly how to revert before you need to

Deployment Strategies

• Rolling: update instances one by one — safe, slower, no extra resources
• Blue-green: full parallel environment, instant switch — fast rollback, 2x resources
• Canary: route percentage to new version — catch issues early, complex routing
• Choose based on risk tolerance and resources — no universal best

Zero-Downtime Deploys

• Health checks must pass before traffic routes — unhealthy instances stay out
• Graceful shutdown: finish in-flight requests before terminating
• Database changes must be backwards compatible — old code still running during deploy
• Session handling: sticky sessions or external session store — don't lose user state

CI/CD Pipeline

• Build once, deploy everywhere — same artifact to staging and prod
• Cache dependencies between builds — save minutes per deploy
• Parallel steps where possible — tests, linting, security scans
• Fail fast: quick checks first — don't wait for slow tests to catch typos
• Pin action versions with SHA — tags can change unexpectedly

Environment Management

• Staging mirrors prod — different configs cause "works in staging" bugs
• Secrets in secret manager, not environment files — rotation without redeploy
• Feature flags decouple deploy from release — ship dark, enable later
• Config as code in version control — except secrets

Database Migrations

• Migrations must be backwards compatible during deploy window
• Add columns nullable first, then backfill, then add constraint
• Never rename columns in one step — add new, migrate data, remove old
• Test migrations on prod-size data — 10 rows is fast, 10 million isn't
• Rollback script for every migration

Rollback

• Automated rollback on health check failure
• Keep previous version artifacts available — can't rollback what you deleted
• Database rollbacks are hard — design migrations to not need them
• Feature flags for instant rollback of functionality without deploy
• Document rollback procedure — panic time is not learning time

Monitoring Post-Deploy

• Watch error rates for 15 minutes after deploy — most issues surface quickly
• Compare key metrics to pre-deploy baseline
• Alerting on anomalies: latency spike, error rate increase
• Log correlation: trace requests through systems
• User-facing smoke tests after deploy

Platform-Specific

Containers

• Image tagged with git SHA — know exactly what's running
• Health check endpoint that verifies dependencies
• Resource limits set — prevent runaway containers

Serverless

• Cold start optimization — keep bundles small
• Provisioned concurrency for latency-sensitive paths
• Timeout set appropriately — default is often too short

Static Sites

• CDN cache invalidation after deploy
• Immutable assets with content hashes — cache forever
• Preview deploys for PRs

Common Mistakes

• Deploying Friday afternoon — issues surface when nobody's watching
• No rollback plan — hoping nothing goes wrong isn't a strategy
• Mixing code and migration deploys — one thing at a time
• Manual deploy steps — if it's not automated, it's wrong sometimes
• Deploying without monitoring — you won't know it's broken until users complain