feat: adds core of golang application with chi, router, middlewares, …

SOLUTION.md

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+# Solution Documentation
+
+## Overview
+
+This solution implements a complete full-stack college review search application as specified in the requirements. The system consists of a Go backend with comprehensive Redis integration and a modern React frontend with TypeScript, Material-UI, and advanced user interaction features.
+
+The implementation addresses all requirements from the README while adding production-ready features including structured logging, input validation, caching strategies, and comprehensive error handling.
+
+## Requirements Implementation
+
+### Backend Requirements
+
+#### 1. loadReviews Function Implementation
+
+- **CSV Processing**: Complete implementation that parses the niche_reviews.csv file
+- **Data Structure**: In-memory ReviewsData structure with Redis persistence backing
+- **Operations Support**: Full support for college lookups and autocomplete functionality
+- **Performance**: Optimized data loading with concurrent processing and Redis caching
+
+#### 2. handleGetReviews Endpoint Implementation
+
+- **URL Parameter Handling**: Accepts college URL parameter via query string
+- **Review Retrieval**: Returns all reviews for the specified college
+- **Error Handling**: Comprehensive error responses with proper HTTP status codes
+- **Validation**: Input validation with custom rules for URL safety
+
+#### 3. handleAutocomplete Endpoint Implementation
+
+- **Query Processing**: Accepts search query and returns matching colleges
+- **Response Format**: Returns college name and URL as specified
+- **Performance**: Debounced search with Redis caching for optimal response times
+- **Result Limiting**: Intelligent result limiting to prevent performance degradation
+
+### Frontend Requirements
+
+#### 1. Autocomplete Component
+
+- **Search Functionality**: Real-time college name search with debouncing
+- **Visual Feedback**: Loading states, error handling, and smooth animations
+- **Keyboard Navigation**: Full arrow key navigation, enter selection, escape clearing
+- **Accessibility**: ARIA labels, screen reader support, and keyboard accessibility
+- **Modern Styling**: Material-UI components with custom theming and animations
+
+#### 2. Review Display Component
+
+- **College Selection**: Automatic review fetching when college is selected
+- **Review Formatting**: Clean, readable review presentation with structured layout
+- **Loading States**: Skeleton loading animations and proper error states
+- **Responsive Design**: Mobile-first design that works across all devices
+- **Empty States**: Informative messages when no reviews are available
+
+## Technical Architecture
+
+### Backend Architecture
+
+#### Framework and Libraries
+
+- **Chi Router**: Lightweight, fast HTTP router with middleware support
+- **Zap Logger**: Structured JSON logging for production observability
+- **Go-Playground Validator**: Comprehensive request validation framework
+- **Redis**: Primary caching layer with graceful fallback to in-memory operations
+- **Docker**: Containerized deployment with multi-service orchestration
+
+#### Data Structure Design
+
+- **Hybrid Storage**: In-memory maps for fast lookups with Redis persistence
+- **Indexed Access**: O(1) college lookups by URL for optimal performance
+- **Search Optimization**: Preprocessed college list for efficient autocomplete
+- **Concurrent Safety**: Mutex-protected data structures for thread safety
+
+#### API Design
+
+```
+GET /health - Health check with system status
+GET /autocomplete?q=query - College name search
+GET /reviews?college=url - College review retrieval
+GET /redis/status - Redis connection and performance statistics
+POST /redis/clear-cache - Clear Redis cache for development/maintenance
+```
+
+#### Input Validation System
+
+- **Custom Validation Rules**: URL-safe character validation (alpha-dash pattern)
+- **Request Sanitization**: Query length limits (2-100 characters)
+- **Structured Error Responses**: Field-specific validation error messages
+- **Security**: Input sanitization to prevent injection attacks
+
+#### Redis Management Features
+
+- **Status Monitoring**: `/redis/status` endpoint provides comprehensive Redis connection statistics
+- **Performance Metrics**: Memory usage, connection status, and operation statistics
+- **Cache Management**: `/redis/clear-cache` endpoint for development and maintenance operations
+- **Health Monitoring**: Redis connectivity status integrated into system health checks
+
+### Frontend Architecture
+
+#### Technology Stack
+
+- **Next.js 15**: React framework with App Router for optimal performance
+- **TypeScript**: Full type safety throughout the application
+- **Material-UI 7**: Modern component library with custom theming
+- **React Query**: Server state management with caching and synchronization
+- **Framer Motion**: Smooth animations and micro-interactions
+
+#### Component Architecture
+
+- **Modular Design**: Reusable components with clear separation of concerns
+- **Custom Hooks**: Centralized API logic with React Query integration
+- **Theme Provider**: Consistent design system across all components
+- **Error Boundaries**: Comprehensive error handling with user-friendly fallbacks
+
+#### State Management
+
+- **React Query**: Server state caching, synchronization, and background updates
+- **Local State**: Component-level state for UI interactions
+- **Controlled Components**: Proper form state management preventing controlled/uncontrolled warnings
+
+## Key Implementation Decisions
+
+### Performance Optimizations
+
+#### Backend Performance
+
+- **Redis Caching**: Primary data store with automatic fallback
+- **Connection Pooling**: Optimized Redis connection management
+- **Concurrent Processing**: Goroutines for non-blocking operations
+- **Smart Indexing**: Multiple data structure views for different access patterns
+
+#### Frontend Performance
+
+- **Debouncing**: 500ms search debouncing to prevent excessive API calls
+- **Request Cancellation**: Automatic cleanup of stale requests
+- **Skeleton Loading**: Non-blocking UI with loading animations
+- **Memoization**: Optimized re-renders with React.memo and useMemo
+
+### User Experience Features
+
+#### Autocomplete Enhancements
+
+- **Smart Triggering**: Minimum 3 characters before search activation
+- **Visual Feedback**: Loading spinners, error states, and result counts
+- **Keyboard Navigation**: Full keyboard support with proper focus management
+- **Animation**: Smooth transitions and micro-interactions
+
+#### Review Display Enhancements
+
+- **Progressive Loading**: Immediate feedback with skeleton placeholders
+- **Error Recovery**: Retry mechanisms with clear error messaging
+- **Responsive Grid**: Adaptive layout for different screen sizes
+- **Typography**: Optimized readability with proper contrast and spacing
+
+### Production Readiness
+
+#### Error Handling
+
+- **Graceful Degradation**: System continues operating when Redis is unavailable
+- **Structured Logging**: JSON logs with correlation IDs for debugging
+- **HTTP Status Codes**: Proper status codes for different error conditions
+- **User-Friendly Messages**: Clear error communication without technical details
+
+#### Security Considerations
+
+- **Input Validation**: Comprehensive validation preventing injection attacks
+- **CORS Configuration**: Proper cross-origin resource sharing setup
+- **Rate Limiting Ready**: Architecture prepared for rate limiting implementation
+- **Sanitization**: Input sanitization for all user-provided data
+
+## Testing Strategy
+
+### Backend Testing
+
+- **Unit Tests**: Individual function testing with comprehensive coverage
+- **Integration Tests**: End-to-end API testing with real Redis operations
+- **Error Scenarios**: Testing error conditions and fallback mechanisms
+- **Performance Tests**: Load testing and benchmarking critical paths
+
+### Frontend Testing
+
+- **Component Testing**: Individual component testing with React Testing Library
+- **Integration Testing**: User interaction flows and API integration
+- **Accessibility Testing**: Screen reader compatibility and keyboard navigation
+- **Error State Testing**: Error boundary and error state validation
+
+## AI Tool Usage Documentation
+
+### Tools Utilized
+
+- **GitHub Copilot**: Code completion and boilerplate generation
+- **Claude/ChatGPT**: Architecture design discussion and code review
+
+### Specific Use Cases
+
+#### Backend Development
+
+- **Prompt**: "Generate production-ready Go middleware for CORS and structured logging"
+- **Prompt**: "Create comprehensive input validation with go-playground/validator for REST API"
+- **Prompt**: "Implement Redis caching layer with graceful fallback to in-memory operations"
+
+#### Frontend Development
+
+- **Prompt**: "Create TypeScript autocomplete component with Material-UI and debouncing"
+- **Prompt**: "Implement React Query integration with proper error handling and loading states"
+- **Prompt**: "Design responsive review display component with skeleton loading animations"
+
+#### Code Quality
+
+- **Prompt**: "Review this caching strategy for performance and reliability concerns"
+- **Prompt**: "Validate this component architecture for maintainability and scalability"
+
+### AI Verification Process
+
+- All AI-generated code was manually reviewed for correctness and security
+- Performance implications were analyzed and optimized where necessary
+- Code was thoroughly tested before integration
+- Security considerations were validated against best practices
+
+## Challenges and Solutions
+
+### Challenge 1: Controlled vs Uncontrolled Component State
+
+**Problem**: Material-UI Autocomplete was switching between controlled and uncontrolled states
+
+**Solution**: Ensured all state values are never undefined by providing proper initial states
+
+```typescript
+const [inputValue, setInputValue] = useState('');
+const [selectedCollege, setSelectedCollege] = useState<College | null>(null);
+```
+
+### Challenge 2: API Endpoint Mismatch
+
+**Problem**: Frontend expected `/reviews/{url}` but backend implemented `/reviews?college={url}`
+
+**Solution**: Standardized on query parameter approach for consistency and flexibility
+
+### Challenge 3: React Key Prop Warning
+
+**Problem**: Spreading props object containing key prop in list rendering
+
+**Solution**: Extracted key from props object and passed directly to JSX elements
+
+### Challenge 4: Excessive API Calls
+
+**Problem**: Autocomplete was triggering API calls for every keystroke
+
+**Solution**: Implemented intelligent debouncing with minimum character threshold and user typing state tracking
+
+## Deployment Instructions
+
+### Development Environment
+
+```bash
+# Start Redis (required for backend)
+docker-compose up -d redis
+
+# Backend
+cd back-end
+go mod tidy
+go run .
+
+# Frontend  
+cd front-end
+pnpm install
+pnpm dev
+```
+
+### Production Deployment
+
+```bash
+# Full stack with Docker (includes Redis)
+docker-compose up -d
+
+# Manual deployment with Redis
+# 1. Start Redis: docker run -d -p 6379:6379 redis:alpine
+# 2. Backend: go build && ./main
+# 3. Frontend: pnpm build && pnpm start
+```
+
+### Environment Configuration
+
+- **Backend**: PORT, REDIS_URL, LOG_LEVEL environment variables
+- **Frontend**: NEXT_PUBLIC_API_URL for API endpoint configuration
+- **Docker**: Complete orchestration with health checks and volume management
+
+### API Usage Examples
+
+```bash
+# Core functionality
+curl "http://localhost:8080/autocomplete?q=harvard"
+curl "http://localhost:8080/reviews?college=harvard-university"
+
+# System monitoring
+curl "http://localhost:8080/health"
+curl "http://localhost:8080/redis/status"
+
+# Cache management (development)
+curl -X POST "http://localhost:8080/redis/clear-cache"
+```
+
+## Future Improvements
+
+### With Additional Time
+
+1. **Database Integration**: PostgreSQL with proper indexing for larger datasets
+2. **Authentication**: JWT-based authentication with user sessions
+3. **Real-time Updates**: WebSocket integration for live review updates
+4. **Advanced Search**: Full-text search with Elasticsearch integration
+5. **Analytics**: Usage analytics and performance monitoring dashboard
+6. **Content Management**: Admin interface for review moderation
+7. **Mobile App**: React Native application for mobile users
+
+### Scalability Enhancements
+
+1. **Microservices**: Service decomposition for independent scaling
+2. **CDN Integration**: Static asset caching and global distribution
+3. **Load Balancing**: Horizontal scaling with load balancer configuration
+4. **Caching Strategy**: Multi-layer caching with Redis Cluster
+5. **API Gateway**: Rate limiting, authentication, and request routing

back-end/.dockerignore

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+# Build artifacts
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool
+*.out
+
+# Dependency directories
+vendor/
+
+# Go workspace file
+go.work
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# OS generated files
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Log files
+*.log
+
+# Temporary files
+*.tmp
+*.temp
+
+# Binary executables
+server
+main
+fullstack-exercise
+kilo-4367-coding-exercise
+
+# Docker files (we don't need them in the container)
+docker-compose.yml
+Dockerfile
+
+# Demo and documentation
+redis-demo.sh
+demo-validation.sh
+REDIS_IMPLEMENTATION.md
+README.md