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+# PyTorch Test Infrastructure
+
+PyTorch Test Infrastructure is a multi-language repository containing CI/CD infrastructure, web applications, and development tools supporting the PyTorch ecosystem. The main components are TorchCI (Next.js web application), Terraform AWS GitHub Runner modules, Python utilities, and AWS Lambda functions.
+
+Always reference these instructions first and fallback to search or bash commands only when you encounter unexpected information that does not match the info here.
+
+## Working Effectively
+
+### Bootstrap and Setup
+- **NEVER CANCEL builds or tests** - they may take 45+ minutes. Use timeouts of 60+ minutes for builds, 30+ minutes for tests.
+- Install dependencies and bootstrap the repository:
+  - Ensure Node.js v20+ and Python 3.12+ are available
+  - Install yarn: `npm install -g yarn` (if not present)
+  - Check versions: `node --version`, `python3 --version`, `yarn --version`
+
+### Linting and Code Quality
+- **Primary linting system**: `pip3 install lintrunner==0.12.5 boto3-stubs==1.34.51`
+- Initialize linters: `lintrunner init` -- takes ~26 seconds. NEVER CANCEL.
+- Run linting: `lintrunner --force-color --all-files` for full repo or `lintrunner <file>` for specific files
+- **Known issue**: actionlint component may fail due to network restrictions - document but continue
+- **Timing**: Single file linting ~1 second, full repo linting ~5-10 minutes
+
+### TorchCI Web Application (Primary Component)
+- **Location**: `/torchci` directory
+- **Technology**: Next.js 14 + TypeScript + React
+- **Setup workflow**:
+  - `cd torchci`
+  - `yarn install --frozen-lockfile` -- takes ~82 seconds. NEVER CANCEL. Set timeout to 120+ seconds.
+  - `yarn lint` -- takes ~7 seconds
+  - `yarn tsc` -- takes ~15 seconds (TypeScript compilation)
+  - `yarn build` -- takes ~107 seconds (1m 47s). NEVER CANCEL. Set timeout to 180+ seconds.
+  - `yarn test` -- takes ~10 seconds
+- **Development server**:
+  - `yarn dev` -- starts in ~1.4 seconds
+  - Runs on http://localhost:3000
+  - **Note**: Many features require API credentials in `.env.local` (see `.env.example`)
+- **Full validation workflow**: `yarn install --frozen-lockfile && yarn lint && yarn tsc && yarn build && yarn test`
+
+### Terraform AWS GitHub Runner (Infrastructure)
+- **Location**: `/terraform-aws-github-runner/modules/runners/lambdas/runners`
+- **Technology**: TypeScript + AWS Lambda
+- **Setup workflow**:
+  - `cd terraform-aws-github-runner/modules/runners/lambdas/runners`
+  - `yarn install` -- takes ~24 seconds
+  - `yarn commit-check` -- takes ~60 seconds. NEVER CANCEL. Set timeout to 120+ seconds.
+  - This runs: format + lint + test + build
+- **Commands available**:
+  - `yarn test` -- Run unit tests
+  - `yarn lint` -- ESLint
+  - `yarn build` -- TypeScript compilation with ncc
+  - `yarn dist` -- Build + create lambda zip
+  - `yarn format` -- Prettier formatting
+
+### Python Tools and Utilities
+- **Main tools location**: `/tools/torchci`
+- **Requirements**: See `requirements.txt` files in various subdirectories
+- **Known issue**: pip installs may timeout due to network restrictions - document timeouts
+- **Setup**: `pip3 install -r requirements.txt` then `pip3 install -e .`
+- **Testing**: `pytest tests/` (when dependencies are available)
+
+### AWS Lambda Functions
+- **Locations**: `/aws/lambda/*` directories
+- **Each has own Makefile and requirements.txt**
+- **Technology**: Python-based
+- **Build**: `make build` in respective directories
+
+## Validation Scenarios
+
+After making changes, ALWAYS run these validation scenarios to ensure functionality:
+
+### TorchCI Web Application Validation
+1. **Build validation**: `cd torchci && yarn install --frozen-lockfile && yarn build`
+2. **Development server test**: `yarn dev` - verify starts on http://localhost:3000
+3. **Code quality**: `yarn lint && yarn tsc && yarn test`
+4. **Manual testing**: If server starts, basic page loads confirm core functionality
+
+### Lambda Infrastructure Validation
+1. **Runner lambda**: `cd terraform-aws-github-runner/modules/runners/lambdas/runners && yarn commit-check`
+2. **Other lambdas**: Check Makefile in `/aws/lambda/*` directories and run `make build`
+
+### Repository-wide Validation
+1. **Linting**: `lintrunner --force-color --all-files` (may take 5-10 minutes)
+2. **Formatting**: Included in lintrunner workflow
+3. **Python tools**: Test individual tools with their specific requirements
+
+## Critical Timing and Timeout Information
+
+- **TorchCI yarn install**: 82 seconds - Set timeout to 120+ seconds. NEVER CANCEL.
+- **TorchCI yarn build**: 107 seconds - Set timeout to 180+ seconds. NEVER CANCEL.
+- **Lambda yarn commit-check**: 60 seconds - Set timeout to 120+ seconds. NEVER CANCEL.
+- **Lintrunner init**: 26 seconds - Set timeout to 60+ seconds. NEVER CANCEL.
+- **Full repository linting**: 5-10 minutes - Set timeout to 15+ minutes. NEVER CANCEL.
+- **Python pip installs**: May timeout due to network - document but continue with available tools
+
+## Common Issues and Workarounds
+
+### Network Limitations
+- **pip install timeouts**: Document as "pip install fails due to network limitations"
+- **actionlint S3 download fails**: Expected in restricted environments, other linters work
+- **Always wait full timeout periods** before concluding failures
+
+### Missing Dependencies
+- **TorchCI .env.local**: Most functionality requires API credentials, but basic build/dev server works
+- **AWS credentials**: Lambda testing requires AWS access, but builds work without
+
+### Build Failures
+- **Always run lintrunner** before committing changes to catch formatting/style issues
+- **TypeScript errors**: Run `yarn tsc` to catch before build
+- **Test failures**: Run individual test suites to isolate issues
+
+## Key Projects Summary
+
+1. **TorchCI** (`/torchci`): Main web dashboard (hud.pytorch.org) - Next.js application
+2. **GitHub Runner Infrastructure** (`/terraform-aws-github-runner`): AWS-based CI runner management
+3. **Python Utilities** (`/tools`, `/aws/lambda`): CI/CD automation and monitoring tools
+4. **Linting Infrastructure** (`/.lintrunner.toml`): Multi-language code quality enforcement
+
+## Repository Quick Facts
+- **Primary languages**: TypeScript, Python, HCL (Terraform)
+- **Package managers**: yarn (Node.js), pip (Python)
+- **Build systems**: Next.js, tsc, ncc, Make
+- **Testing**: Jest (JS/TS), pytest (Python)
+- **Linting**: lintrunner with 15+ specialized linters
+- **Main branch**: `main`
+- **CI/CD**: GitHub Actions (see `.github/workflows/`)
+
+Always build and exercise your changes using the validation scenarios above to ensure they integrate properly with the existing infrastructure.
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