Backend Design
More than just CRUD
On this page is like a Roadmap ig?
Introduction to Backend Systems
- High-level understanding of backend systems
- Request flow from browser to server
- Network hops, firewalls, routing
- Client-server communication model
- Response structure and handling
HTTP Protocol Deep Dive
- HTTP message structure and format
- HTTP headers (request, response, representational, general, security)
- HTTP methods (GET, POST, PUT, DELETE, PATCH, etc.)
- HTTP status codes and when to use them
- CORS (Cross-Origin Resource Sharing)
- Simple requests vs. pre-flight requests
- CORS headers and configuration
- HTTP caching mechanisms (ETags, max-age)
- HTTP versions comparison (1.1 vs 2.0 vs 3.0)
- Content negotiation between client and server
- Persistent connections
- HTTP compression techniques (gzip, deflate, Brotli)
- HTTPS, SSL/TLS security
API Design and Routing
- Route mapping (URLs to server-side logic)
- Components of routes (path parameters, query parameters)
- Route types:
- Static routes
- Dynamic routes
- Nested routes
- Hierarchical routes
- Wildcard/catch-all routes
- Regular expression-based routes
- API versioning techniques
- API deprecation strategies
- Route grouping benefits
- Route security
- Route matching performance optimization
- RESTful architecture principles
- REST API best practices
- OpenAPI/Swagger specification
- API-first development approach
Serialization and Deserialization
- Purpose and benefits (interoperability)
- Text-based formats (JSON, XML, YAML)
- Binary formats (Protocol Buffers, MessagePack, BSON)
- Performance comparisons and tradeoffs
- Implementation across programming languages
- JSON deep dive:
- Structure and data types
- Handling nested objects and collections
- Mapping to native data structures
- Common errors (missing fields, null values, date serialization)
- Custom serialization implementation
- Error handling
- Security concerns (injection attacks)
- Validation before deserialization
- JSON Schema validation
- Performance considerations
- Compression techniques
Authentication and Authorization
- Authentication types:
- Stateful vs. stateless authentication
- Basic authentication
- Token-based authentication
- Session-based authentication
- JWT (JSON Web Tokens)
- Cookies
- OAuth 2.0 protocol and OpenID Connect
- API keys
- Multi-factor authentication
- Cryptographic techniques (salting, hashing)
- Authorization models:
- ACL (Access Control Lists)
- RBAC (Role-Based Access Control)
- ABAC (Attribute-Based Access Control)
- Security best practices:
- Secure cookies
- CSRF and XSS prevention
- MITM attack prevention
- Audit logging
- Obfuscating error messages
- Rate limiting and account lockout
- Preventing timing attacks
Input Validation and Transformation
- Validation types:
- Syntactic validation (format, pattern)
- Semantic validation (business rules)
- Type validation (data types)
- Client-side vs. server-side validation
- Failing fast principles
- Transformation types:
- Type casting
- Date format conversion
- Normalization (case conversion, whitespace trimming)
- Sanitization (security)
- Complex validation logic:
- Relationship-based validation
- Conditional validation
- Chain validation
- Error handling in validation
- Validation performance optimization
Middleware Architecture
- Middleware concept and use cases
- Request lifecycle middleware (pre-request, post-response)
- Middleware chaining and flow
- Proper middleware ordering
- Next function and early exit patterns
- Common middleware types:
- Security middlewares (headers, CORS, CSRF)
- Rate limiting middleware
- Authentication middleware
- Logging and monitoring middleware
- Error handling middleware
- Compression middleware
- Body parsing middleware
- Performance and scalability considerations
Request Context
- Request-scoped state management
- Components of request context:
- Request metadata (method, URL, headers, params)
- Session and user information
- Tracking and logging data
- Custom request-specific data
- Use cases (authentication, rate limiting, tracing)
- Timeouts and cancellation signals
- Best practices and performance considerations
Handlers and Controllers
- MVC pattern overview
- Responsibilities of handlers, controllers, and services
- Code reduction with middleware
- Centralized error handling
- Response formatting standards
- CRUD operations implementation:
- Creating resources (POST)
- Reading resources (GET)
- Updating resources (PUT, PATCH)
- Deleting resources (DELETE)
- Pagination implementation
- Search API design
- Sorting and filtering implementation
- RESTful best practices
Database Management
- Relational vs. non-relational databases
- Theoretical concepts (ACID, CAP theorem)
- Querying and joins
- Database design best practices:
- Schema design
- Indexing strategies
- Normalization and denormalization
- Optimization techniques:
- Query optimization
- Caching strategies
- Connection pooling
- Data integrity:
- Constraints and validations
- Transactions
- Concurrency control
- ORM (Object-Relational Mapping):
- Benefits and tradeoffs
- Popular ORM tools
- Database migrations
- NoSQL databases:
- Document stores (MongoDB)
- Key-value stores (Redis)
- Column-family stores (Cassandra)
- Graph databases (Neo4j)
- Database sharding and replication
Business Logic Layer
- Role and responsibilities
- Application layers:
- Presentation layer
- Business logic layer
- Data access layer
- Design principles:
- Separation of concerns
- Single responsibility
- Open/closed principle
- Dependency inversion
- Components:
- Services
- Domain models
- Business rules
- Business validation
- Service layer design best practices
- Error handling and propagation
Caching Strategies
- Purpose and benefits
- Caching types:
- Memory caching
- Browser caching
- Database caching
- Client-side vs. server-side caching
- Caching strategies:
- Cache-aside
- Write-through
- Write-behind/Write-back
- Read-through
- Cache eviction strategies:
- LRU (Least Recently Used)
- LFU (Least Frequently Used)
- TTL (Time To Live)
- FIFO (First In First Out)
- Cache invalidation approaches
- Caching levels:
- Level 1 (in-memory)
- Level 2 (distributed)
- Hierarchical caching
- Web application caching (static assets, API responses)
- Database query caching
- Cache hit/miss ratio optimization
Transactional Emails
- Use cases and common scenarios
- Email anatomy:
- Subject
- Preheader
- Body (header, content, CTA, footer)
- Personalization with dynamic parameters
- Email templating systems
- Email delivery services and APIs
- Tracking and analytics
- Best practices for deliverability
Task Queuing and Scheduling
- Use cases:
- Email sending
- File processing
- Third-party API integration
- Heavy computation
- Batch processing
- Scheduling use cases:
- Database backups
- Notifications and reminders
- Data synchronization
- Maintenance tasks
- Task queue components:
- Producer
- Queue
- Consumer
- Broker
- Backend
- Task dependencies:
- Chain dependency
- Parent-child relationship
- Task groups for concurrent execution
- Error handling and retry mechanisms
- Task prioritization and rate limiting
- Popular task queue systems (RabbitMQ, Kafka, Redis Queue)
Elasticsearch and Search
- Elasticsearch fundamentals
- Underlying techniques:
- Inverted index
- Term frequency and inverse document frequency
- Segments and shards
- Use cases:
- Type-ahead/autocomplete
- Log analytics
- Full-text search
- Index creation and management
- Search and query types:
- Basic search
- Full-text search
- Relevance scoring
- Performance optimization:
- Field mapping (text vs. keyword)
- Analyzers and tokenizers
- Boosting
- Pagination
- Advanced search patterns:
- Filtering
- Aggregation
- Fuzzy search
- Kibana integration
- Best practices
Error Handling
- Error types:
- Syntax errors
- Runtime errors
- Logical errors
- Error handling strategies:
- Fail-safe vs. fail-fast
- Graceful degradation
- Error prevention
- Best practices:
- Early catching
- Custom error types
- Graceful failure
- Proper logging
- Stack trace utilization
- Global error handlers
- User-facing error handling
- Monitoring and logging integration
- Error alerting systems
Configuration Management
- Purpose and benefits
- Use cases:
- Environment-specific settings
- Sensitive data management
- Feature flags
- Configuration types:
- Static configs
- Dynamic configs
- Sensitive configs
- Configuration sources:
- Environment variables
- Command-line flags
- Static files (JSON, YAML, INI)
- Best practices
- Configuration security
Logging, Monitoring, and Observability
- Differences between logging, tracing, monitoring, and observability
- Logging types:
- System logs
- Application logs
- Access logs
- Security logs
- Log levels (debug, info, warn, error, fatal)
- Structured vs. unstructured logging
- Logging best practices
- Monitoring types:
- Infrastructure monitoring
- Application performance monitoring
- Uptime monitoring
- Monitoring tools (Prometheus, Grafana)
- Alerts and notifications
- Observability pillars:
- Logs
- Metrics
- Traces
- Log management security and compliance
- Distributed tracing in microservices
Graceful Shutdown
- Purpose and importance
- Use cases (server restarts, scaling, microservices)
- Signal handling (SIGTERM, SIGINT)
- Graceful shutdown steps:
- Signal capture
- Stop accepting requests
- Complete in-flight requests
- Close external resources
- Terminate application
- Implementation patterns
- Best practices
Security Best Practices
- Common attacks and prevention:
- SQL injection
- NoSQL injection
- XSS (Cross-Site Scripting)
- CSRF (Cross-Site Request Forgery)
- Broken authentication
- Insecure deserialization
- Secure software design principles:
- Least privilege
- Defense in depth
- Fail secure
- Separation of duties
- Security by design
- Input validation and sanitization
- Rate limiting
- Content Security Policy
- CORS configuration
- Secure cookies
- Security monitoring
- OWASP Top 10 awareness
Scaling and Performance
- Performance metrics:
- Response time
- Resource utilization
- Throughput
- Bottleneck identification
- Caching strategies
- Database optimization:
- N+1 query problem
- Proper joins
- Lazy loading
- Indexes
- Batch processing
- Memory management:
- Avoiding leaks
- Resource cleanup
- Network optimization:
- Payload size reduction
- Compression
- Performance testing and profiling
- Code performance best practices
- Horizontal vs. vertical scaling
- Load balancing strategies
Concurrency and Parallelism
- Differences and use cases
- Concurrency for I/O-bound tasks
- Parallelism for CPU-bound tasks
- Concurrency patterns
- Thread safety
- Race conditions and deadlocks
- Synchronization mechanisms
- Asynchronous programming patterns
File Storage and Management
- Object storage (AWS S3, Google Cloud Storage)
- Large file handling:
- Chunking
- Streaming
- Multi-part file uploads
- File validation and security
- Content delivery networks
- File metadata management
Real-time Backend Systems
- WebSockets
- Server-Sent Events (SSE)
- Pub/Sub architecture
- Real-time databases
- Scaling real-time systems
- Implementation patterns
- Popular frameworks and tools
Testing and Code Quality
- Testing types:
- Unit testing
- Integration testing
- End-to-end testing
- Functional testing
- Regression testing
- Performance testing
- Load and stress testing
- User acceptance testing
- Security testing
- Test-driven development (TDD)
- CI/CD integration
- Code quality tools:
- Linting
- Formatting
- Static analysis
- Code quality metrics:
- Cyclomatic complexity
- Maintainability index
- Code coverage
- Mocking and stubbing
- Test data management
12-Factor App Methodology
- Codebase
- Dependencies
- Configuration
- Backing services
- Build, release, run
- Processes
- Port binding
- Concurrency
- Disposability
- Dev/prod parity
- Logs
- Admin processes
- Implementation patterns
OpenAPI Standards
- Purpose and benefits
- History (Swagger to OpenAPI)
- Versions and features
- Key concepts:
- API paths
- Request/response definitions
- Parameters
- Schemas
- Document structure:
- Metadata
- Paths
- Components
- Security definitions
- Responses
- OpenAPI 3.0/3.1 features
- Tools (Swagger UI, Postman)
- Best practices
- API-first development
Webhooks
- Use cases and benefits
- API vs. webhook comparison
- Components:
- Webhook URL
- Event triggers
- Payload
- HTTP method
- Response handling
- Best practices:
- Signature verification
- HTTPS usage
- Quick response
- Retry logic
- Logging
- Testing strategies
- Real-world examples
DevOps for Backend Engineers
- Core concepts:
- Continuous Integration (CI)
- Continuous Delivery (CD)
- Continuous Deployment
- DevOps practices:
- Infrastructure as Code
- Configuration management
- Version control
- DevOps tools:
- Docker (containerization)
- Kubernetes (orchestration)
- CI/CD pipelines
- Scaling strategies:
- Horizontal vs. vertical scaling
- Deployment strategies:
- Blue/green deployment
- Rolling deployment
- Canary deployment
- Monitoring and observability in DevOps
- Incident response and management
Additional Topics (Filling the Gaps)
Microservices Architecture
- Monolithic vs. microservices
- Service decomposition strategies
- Inter-service communication:
- REST
- gRPC
- Message queues
- API Gateway pattern
- Service discovery
- Circuit breaker pattern
- Distributed transactions
- Microservices testing
- Deployment strategies
GraphQL
- GraphQL vs. REST
- Schema definition
- Queries and mutations
- Resolvers
- GraphQL tools and libraries
- Performance optimization
- Security considerations
- Versioning approach
Serverless Architecture
- Function as a Service (FaaS)
- Serverless frameworks
- Event-driven architecture
- Cold start problem
- State management
- Serverless databases
- Cost optimization
- Limitations and challenges
Data Streaming and Event-Driven Architecture
- Event sourcing
- CQRS pattern
- Stream processing
- Kafka architecture
- Event-driven design patterns
- Idempotency and exactly-once processing
- Backpressure handling
- Stream analytics
Internationalization and Localization
- i18n fundamentals
- Locale management
- Date, time, and number formatting
- Translation management
- Right-to-left (RTL) support
- Character encoding issues
- Best practices
Domain-Driven Design (DDD)
- Strategic design
- Tactical patterns
- Bounded contexts
- Ubiquitous language
- Aggregates, entities, value objects
- Domain events
- Implementing DDD in backend systems
Service Mesh
- Concept and benefits
- Control plane vs. data plane
- Popular implementations (Istio, Linkerd)
- Traffic management
- Security features
- Observability enhancements
- Integration with Kubernetes
Blockchain for Backend Developers
- Blockchain fundamentals
- Smart contracts
- Backend integration
- Web3 APIs
- Security considerations
- Performance challenges
- Use cases for traditional backends
Machine Learning Integration
- ML model serving
- Prediction API design
- Model versioning
- Feature engineering
- Online vs. batch prediction
- ML monitoring
- A/B testing frameworks
Compliance and Regulations
- GDPR compliance
- CCPA/CPRA compliance
- PCI DSS for payment systems
- HIPAA for healthcare data
- SOC 2 compliance
- Privacy by design principles
- Data residency requirements
- Regulatory reporting
Learning Path Recommendations
Beginner Level
- Introduction to Backend Systems
- HTTP Protocol Deep Dive
- API Design and Routing
- Handlers and Controllers
- Input Validation and Transformation
- Database Management (basics)
- Error Handling
- Testing and Code Quality (basics)
Intermediate Level
- Authentication and Authorization
- Middleware Architecture
- Request Context
- Business Logic Layer
- Caching Strategies
- Logging, Monitoring, and Observability
- Security Best Practices
- Configuration Management
- Serialization and Deserialization
- Task Queuing and Scheduling
- RESTful APIs and OpenAPI Standards
Advanced Level
- Database Management (advanced)
- Elasticsearch and Search
- Scaling and Performance
- Concurrency and Parallelism
- Real-time Backend Systems
- Graceful Shutdown
- File Storage and Management
- 12-Factor App Methodology
- DevOps for Backend Engineers
- Webhooks
- Microservices Architecture
- GraphQL
- Serverless Architecture
- Data Streaming and Event-Driven Architecture
Specialized Skills
- Domain-Driven Design
- Service Mesh
- Machine Learning Integration
- Blockchain for Backend Developers
- Internationalization and Localization
- Compliance and Regulations
Resources
- Books: “Clean Code” by Robert C. Martin, “Designing Data-Intensive Applications” by Martin Kleppmann
- Online platforms: Udemy, Coursera, Pluralsight
- Documentation: Official framework docs, MDN Web Docs
- Open-source projects: Study popular repositories in your chosen language
- Practice: Build progressively complex projects applying these concepts
- Communities: Stack Overflow, Reddit (r/webdev, r/programming)
- Blogs: High Scalability, Martin Fowler’s blog, The Pragmatic Engineer