aws-deployment-preflightlisted

# AWS Deployment Preflight The AWS analogue of pre-deploy validation: validate locally and clean up state *before* you deploy, so CI doesn't discover what you could have caught. Works for both AWS CDK projects and raw CloudFormation. Continue through all steps even if one fails — capture every issue, then fix them in a batch. > Discipline: **batch your fixes.** Each deploy/CI run costs real minutes. Read the > whole failing stack, reason about every issue, fix them all, push once. One run per > problem cluster, not one per error message. ## When to use - Before `cdk deploy`, `cdk destroy`, `aws cloudformation deploy/create-stack`. - When preparing or reviewing CDK / CloudFormation templates. - To preview what a deploy will change. - After a failed deploy left a stack stuck (`ROLLBACK_COMPLETE`, `*_FAILED`). - Before an "it worked yesterday" infra mystery becomes a CI run. ## Step 1 — Detect project type - **CDK project:** `cdk.json` at root; stacks in `bin/` + `lib/` (TS) or app entry (Python). Identify the app and stack names: `cdk list`. - **Raw CloudFormation:** `.yaml`/`.json` templates (`AWSTemplateFormatVersion`, `Resources:`), often under `infra/`, `cloudformation/`, `templates/`. - Confirm the target account/region: `aws sts get-caller-identity` and `aws configure get region` (or `$AWS_REGION`). Deploying to the wrong account is the most expensive mistake of all. ## Step 2 — Validate the template ### CDK ```bash # Synthesize — fails on construct/TypeS