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Mapagam

55 SECTIONS · 909 TOPICS

Low Level Design Roadmap

  1. Understanding Object-Oriented Principles

    1. 1. Understanding Encapsulation
    2. Example: Encapsulated balance
    3. 2. Understanding Abstraction
    4. Example: Payment abstraction
    5. 3. Understanding Inheritance
    6. 4. Understanding Polymorphism
    7. Example: Subtype polymorphism
    8. 5. Understanding Composition over Inheritance
    9. Example: Compose, don't extend
    10. 6. Understanding Coupling and Cohesion
    11. 7. Understanding Information Hiding
    12. 8. Understanding Separation of Concerns
    13. 9. Understanding Law of Demeter
    14. Example: Tell, don't ask
    15. 10. Understanding DRY Principle
    16. 11. Understanding YAGNI Principle
    17. 12. Understanding KISS Principle

  2. Understanding SOLID Principles

    1. 1. Understanding Single Responsibility Principle
    2. Example: Split responsibilities
    3. 2. Understanding Open-Closed Principle
    4. Example: Strategy keeps it closed
    5. 3. Understanding Liskov Substitution Principle
    6. 4. Understanding Interface Segregation Principle
    7. Example: Role interfaces
    8. 5. Understanding Dependency Inversion Principle
    9. Example: Inverted dependency
    10. 6. Identifying SRP Violations
    11. 7. Applying SOLID in Domain Models
    12. 8. Applying SOLID in Service Layer Design
    13. 9. Balancing SOLID with Pragmatism
    14. Apply Strictly When
    15. Relax When
    16. 10. Refactoring to SOLID
    17. Refactor Sequence
    18. 11. Understanding SOLID Trade-offs
    19. 12. Implementing SOLID in Legacy Code

  3. Understanding Functional Programming Principles

    1. 1. Understanding Pure Functions
    2. Example: Pure vs impure
    3. 2. Understanding Immutability
    4. 3. Understanding Higher-Order Functions
    5. Example: Function as parameter
    6. 4. Understanding Function Composition
    7. Example: Compose pipeline
    8. 5. Understanding Referential Transparency
    9. 6. Understanding First-Class Functions
    10. 7. Implementing Map, Filter, Reduce Patterns
    11. Example: MFR pipeline
    12. 8. Understanding Currying and Partial Application
    13. Example: Curry in Java
    14. 9. Understanding Closures
    15. 10. Implementing Monads
    16. Example: flatMap chain
    17. 11. Understanding Lazy Evaluation
    18. 12. Avoiding Side Effects

  4. Designing Classes and Objects

    1. 1. Defining Class Responsibilities
    2. 2. Implementing Constructors
    3. Example: Validating constructor
    4. 3. Implementing Encapsulation
    5. 4. Designing Method Signatures
    6. 5. Implementing Static vs Instance Members
    7. 6. Designing Immutable Classes
    8. Example: Record as immutable
    9. 7. Implementing Utility Classes
    10. 8. Implementing Value Objects
    11. 9. Implementing Entities
    12. 10. Understanding Composition vs Aggregation
    13. 11. Implementing Data Classes
    14. 12. Designing Object Lifecycle

  5. Designing Interfaces and Abstractions

    1. 1. Designing Interface Contracts
    2. 2. Defining Abstract Classes
    3. 3. Understanding Interface vs Abstract Class
    4. 4. Implementing Multiple Interfaces (composition)
    5. Example: Combine roles
    6. 5. Designing Marker Interfaces
    7. 6. Implementing Default Methods
    8. Example: Default convenience
    9. 7. Implementing Functional Interfaces
    10. 8. Designing API Contracts
    11. 9. Using Interface Segregation
    12. Example: Split a fat interface
    13. 10. Implementing Dependency Abstraction
    14. 11. Designing Sealed Interfaces
    15. Example: Closed hierarchy
    16. 12. Implementing Interface Evolution

  6. Implementing Naming Conventions

    1. 1. Naming Classes
    2. 2. Naming Interfaces
    3. 3. Naming Methods
    4. 4. Naming Variables
    5. 5. Naming Constants
    6. 6. Naming Packages
    7. 7. Naming Test Classes
    8. 8. Using Domain Language
    9. 9. Avoiding Hungarian Notation
    10. 10. Using Intention-Revealing Names
    11. Example: Reveal intent
    12. 11. Naming Boolean Variables
    13. 12. Naming Collections

  7. Organizing Code Structure

    1. 1. Designing Package Structure
    2. 2. Implementing Layered Architecture
    3. 3. Implementing Module Boundaries
    4. 4. Organizing Code by Features
    5. Example: Feature packages
    6. 5. Organizing Code by Layers
    7. Example: Layer packages
    8. 6. Implementing Constants Management
    9. 7. Implementing Exception Hierarchy
    10. 8. Implementing Utility Packages
    11. 9. Implementing Code Documentation
    12. 10. Implementing File Organization
    13. 11. Designing Namespace Structure
    14. 12. Implementing Module Dependencies

  8. Implementing Creational Design Patterns

    1. 1. Implementing Singleton Pattern
    2. Example: Enum singleton
    3. 2. Implementing Factory Method Pattern
    4. Example: Subclass decides type
    5. 3. Implementing Abstract Factory Pattern
    6. Example: Family of products
    7. 4. Implementing Builder Pattern
    8. Example: Fluent builder
    9. 5. Implementing Prototype Pattern
    10. 6. Implementing Factory Pattern
    11. Example: Simple factory
    12. 7. Implementing Simple Factory
    13. 8. Using Static Factory Methods
    14. 9. Choosing Between Factory Patterns
    15. 10. Implementing Object Pool Pattern
    16. 11. Implementing Registry Pattern
    17. Example: Type registry
    18. 12. Implementing Multiton Pattern
    19. 13. Implementing Dependency Injection Pattern
    20. 14. Understanding Dependency Injection
    21. 15. Using Service Locator Pattern
    22. 16. Understanding IoC Containers
    23. 17. Using Service Containers
    24. 18. Understanding Thread-Safe Singleton
    25. 19. Using Double-Checked Locking
    26. Example: Correct DCL
    27. 20. Using Initialization-on-Demand Holder
    28. Example: Holder idiom
    29. 21. Implementing Lazy Initialization
    30. 22. Using Lazy<T> for Lazy Initialization
    31. Example: Memoized supplier
    32. 23. Using Functional Options
    33. Example: Configurer pattern
    34. 24. Using Structs for Simple Factories
    35. 25. Using Class Methods as Factories
    36. Example: Named static creators
    37. 26. Using Companion Objects for Factories
    38. 27. Using Module Mixins for Object Creation

  9. Implementing Structural Design Patterns

    1. 1. Implementing Adapter Pattern
    2. Example: Adapt incompatible interface
    3. 2. Implementing Bridge Pattern
    4. Example: Notification × Channel
    5. 3. Implementing Composite Pattern
    6. Example: Tree of components
    7. 4. Implementing Decorator Pattern
    8. Example: Wrap and add behavior
    9. 5. Implementing Facade Pattern
    10. Example: Order facade
    11. 6. Implementing Flyweight Pattern
    12. 7. Implementing Proxy Pattern
    13. 8. Implementing Repository Pattern
    14. Example: Domain-owned port
    15. 9. Implementing Data Mapper Pattern
    16. 10. Implementing Active Record Pattern
    17. 11. Implementing Unit of Work Pattern
    18. 12. Implementing Module Pattern
    19. 13. Implementing Delegation Pattern
    20. Example: Forward to inner
    21. 14. Understanding Wrapper Pattern
    22. 15. Implementing Private Class Data Pattern
    23. 16. Understanding Adapter vs Decorator vs Proxy
    24. 17. Creating Lazy Initialization Proxy
    25. Example: Virtual proxy
    26. 18. Implementing Virtual Proxy
    27. 19. Using java.lang.reflect.Proxy
    28. Example: Dynamic proxy
    29. 20. Using Class Delegation
    30. 21. Using Embedding for Delegation
    31. 22. Using Extension Methods
    32. 23. Using Extension Methods as Decorators
    33. 24. Using Module Mixins for Decoration
    34. 25. Using SimpleDelegator and DelegateClass

  10. Implementing Behavioral Design Patterns

    1. 1. Implementing Strategy Pattern
    2. Example: Pluggable algorithm
    3. 2. Implementing Observer Pattern
    4. Example: Publish/subscribe
    5. 3. Implementing Command Pattern
    6. Example: Encapsulate request
    7. 4. Implementing Template Method Pattern
    8. Example: Skeleton + hooks
    9. 5. Implementing Iterator Pattern
    10. 6. Implementing Chain of Responsibility Pattern
    11. Example: Pipeline of handlers
    12. 7. Implementing State Pattern
    13. Example: State-driven order
    14. 8. Implementing Visitor Pattern
    15. 9. Implementing Mediator Pattern
    16. 10. Implementing Memento Pattern
    17. Example: Snapshot + restore
    18. 11. Implementing Null Object Pattern
    19. Example: No-op default
    20. 12. Implementing Specification Pattern
    21. Example: Composable predicate
    22. 13. Implementing State Pattern with Sealed Classes
    23. Example: Exhaustive states

  11. Implementing Domain-Driven Design Patterns

    1. 1. Implementing Value Objects
    2. Example: Email value object
    3. 2. Implementing Entities
    4. 3. Implementing Aggregates
    5. 4. Implementing Aggregate Roots
    6. Example: Root enforces invariants
    7. 5. Implementing Domain Services
    8. Example: Pricing domain service
    9. 6. Implementing Domain Events
    10. 7. Designing Rich Domain Models
    11. Rich Model
    12. Anemic Model
    13. 8. Understanding Anemic vs Rich Domain Models
    14. 9. Defining Bounded Contexts
    15. 10. Modeling Business Rules
    16. 11. Designing Entity Relationships
    17. 12. Implementing Factories for Aggregates
    18. Example: Aggregate factory

  12. Implementing Dependency Injection

    1. 1. Implementing Constructor Injection
    2. Example: Constructor injection
    3. 2. Implementing Setter Injection
    4. 3. Understanding Field Injection
    5. 4. Implementing Component Scanning
    6. 5. Implementing Bean Lifecycle
    7. 6. Implementing Scope Management
    8. 7. Implementing Qualifier Annotations
    9. Example: Disambiguate beans
    10. 8. Implementing Conditional Beans
    11. 9. Resolving Circular Dependencies
    12. 10. Implementing Primary Beans
    13. Example: Default among multiple
    14. 11. Implementing Custom Scopes
    15. 12. Understanding Dependency Injection Containers

  13. Implementing Data Transfer Objects

    1. 1. Creating Request DTOs
    2. Example: Request record with validation
    3. 2. Creating Response DTOs
    4. 3. Implementing DTO Mapping
    5. 4. Designing Nested DTOs
    6. Example: Nested response
    7. 5. Using Validation Annotations
    8. 6. Implementing Pagination DTOs
    9. Example: Page response
    10. 7. Implementing Filter DTOs
    11. Example: Search filter
    12. 8. Understanding DTOs vs Domain Models
    13. 9. Implementing Versioned DTOs
    14. 10. Handling Null Values
    15. 11. Implementing Command DTOs
    16. 12. Implementing Query DTOs

  14. Implementing Service Layer

    1. 1. Defining Service Responsibilities
    2. 2. Implementing Service Interfaces
    3. Example: Interface + impl
    4. 3. Implementing Service Transaction Boundaries
    5. 4. Implementing Service Composition
    6. Example: Compose services
    7. 5. Implementing Service Dependencies
    8. 6. Implementing Service Error Handling
    9. 7. Implementing Service Input Validation
    10. 8. Implementing Service Output Transformation
    11. 9. Designing Service Granularity
    12. 10. Understanding Service vs Repository Separation
    13. 11. Implementing Application Services
    14. 12. Implementing Domain Services

  15. Implementing Repository Pattern

    1. 1. Implementing Repository Interface
    2. Example: Domain repository contract
    3. 2. Implementing Generic Repository
    4. Example: Spring Data style
    5. 3. Implementing Specification Pattern
    6. Example: Spring Data JPA Specification
    7. 4. Implementing Unit of Work Pattern
    8. 5. Implementing Query Object Pattern
    9. 6. Implementing Data Access Layer Abstraction
    10. 7. Implementing Repository Methods
    11. 8. Implementing Pagination in Repository
    12. Example: Paged query
    13. 9. Implementing Repository Exception Handling
    14. 10. Implementing Custom Repository Implementations
    15. Example: Spring Data custom impl
    16. 11. Implementing Repository Factory
    17. 12. Implementing Read vs Write Repository
    18. Write Repository
    19. Read Repository

  16. Implementing Data Validation

    1. 1. Implementing Input Validation
    2. Example: Trigger validation in controller
    3. 2. Implementing Business Rule Validation
    4. Example: Enforce in domain
    5. 3. Using Validation Annotations
    6. 4. Implementing Custom Validators
    7. Example: Custom annotation
    8. 5. Implementing Validation Error Messages
    9. 6. Implementing Cross-Field Validation
    10. Example: Class-level constraint
    11. 7. Implementing Validation Groups
    12. 8. Implementing Input Sanitization
    13. 9. Implementing Schema Validation
    14. 10. Understanding Fail-Fast vs Collect-All Validation
    15. 11. Implementing Fluent Validation
    16. Example: Fluent rules
    17. 12. Implementing Domain Model Validation

  17. Designing Database Schema

    1. 1. Normalizing Database Tables
    2. 2. Denormalizing for Performance
    3. 3. Designing Primary Keys
    4. 4. Implementing Foreign Key Relationships
    5. 5. Designing Indexes
    6. 6. Implementing Soft Deletes
    7. Example: Soft-delete column
    8. 7. Implementing Audit Columns
    9. 8. Designing Partitioning Strategies
    10. 9. Using Junction Tables
    11. Example: M:N junction
    12. 10. Implementing Polymorphic Associations
    13. 11. Designing Column Types
    14. 12. Implementing Database Constraints

  18. Implementing Object-Relational Mapping

    1. 1. Implementing Entity Mappings
    2. Example: JPA entity
    3. 2. Implementing Relationships
    4. 3. Implementing Fetch Strategies
    5. 4. Implementing Cascade Operations
    6. 5. Implementing Inheritance Strategies
    7. 6. Implementing Embedded Objects
    8. Example: Embeddable value object
    9. 7. Implementing Entity Listeners
    10. 8. Implementing Named Queries
    11. Example: Named JPQL
    12. 9. Implementing Custom Type Converters
    13. Example: AttributeConverter
    14. 10. Implementing ID Generation Strategies
    15. 11. Implementing Composite Primary Keys
    16. Example: @EmbeddedId
    17. 12. Implementing Optimistic Locking
    18. Example: @Version

  19. Implementing Database Migration

    1. 1. Implementing Schema Versioning
    2. 2. Implementing Migration Scripts
    3. Example: Flyway migration
    4. 3. Implementing Rollback Scripts
    5. 4. Implementing Baseline Migration
    6. 5. Implementing Repeatable Migrations
    7. 6. Implementing Callback Handlers
    8. 7. Implementing Migration Validation
    9. 8. Implementing Out-of-Order Migrations
    10. 9. Implementing Placeholder Replacement
    11. Example: Per-env placeholder
    12. 10. Implementing Migration Testing
    13. 11. Implementing Data Migrations
    14. 12. Implementing Zero-Downtime Migrations
    15. Expand-Contract Pattern

  20. Implementing Query Optimization

    1. 1. Writing Efficient Queries
    2. 2. Using Query Hints
    3. 3. Implementing Batch Fetching
    4. 4. Implementing Query Result Caching
    5. 5. Implementing N+1 Query Prevention
    6. Example: JOIN FETCH
    7. 6. Implementing Projection Queries
    8. Example: DTO projection
    9. 7. Implementing Native Queries
    10. 8. Analyzing Query Execution Plans
    11. 9. Optimizing Subqueries
    12. 10. Using Criteria API
    13. Example: Type-safe Criteria
    14. 11. Implementing Query Pagination
    15. 12. Implementing Query Indexing Strategy

  21. Implementing Transaction Management

    1. 1. Understanding ACID Properties
    2. 2. Implementing Declarative Transactions
    3. Example: @Transactional
    4. 3. Implementing Programmatic Transactions
    5. Example: TransactionTemplate
    6. 4. Designing Transaction Boundaries
    7. 5. Understanding Transaction Isolation Levels
    8. 6. Implementing Transaction Propagation
    9. 7. Implementing Optimistic Locking
    10. 8. Implementing Pessimistic Locking
    11. Example: SELECT ... FOR UPDATE
    12. 9. Handling Transaction Rollback
    13. 10. Implementing Read-Only Transactions
    14. Example: read-only flag
    15. 11. Understanding Distributed Transactions
    16. 12. Implementing Savepoints
    17. Example: Nested rollback

  22. Designing RESTful APIs

    1. 1. Defining Resource-Based URLs
    2. 2. Using HTTP Methods Correctly
    3. 3. Implementing API Versioning
    4. 4. Implementing HATEOAS
    5. Example: HAL response
    6. 5. Defining Request/Response Contracts
    7. 6. Handling Query Parameters
    8. 7. Designing Error Responses
    9. Example: RFC 7807 Problem Details
    10. 8. Implementing Content Negotiation
    11. 9. Designing Idempotent Operations
    12. 10. Using HTTP Status Codes Appropriately
    13. 11. Implementing Partial Responses
    14. 12. Designing Bulk Operations Endpoints
    15. Example: Bulk endpoint

  23. Implementing API Versioning

    1. 1. Implementing URL Path Versioning
    2. Example: Versioned controller
    3. 2. Implementing Header-Based Versioning
    4. 3. Implementing Query Parameter Versioning
    5. 4. Implementing Content Negotiation Versioning
    6. 5. Implementing Versioned Controllers
    7. 6. Implementing Versioned DTOs
    8. Example: Version packages
    9. 7. Implementing Backward Compatibility Logic
    10. 8. Implementing Deprecation Warnings
    11. Example: Deprecation headers
    12. 9. Implementing Version Migration Logic
    13. 10. Managing Parallel Version Support
    14. 11. Implementing Version Negotiation
    15. 12. Implementing Version Sunset Policy
    16. Sunset Sequence

  24. Implementing API Pagination

    1. 1. Implementing Offset-Based Pagination
    2. Example: Offset query
    3. 2. Implementing Cursor-Based Pagination
    4. Example: Keyset cursor
    5. 3. Designing Page Response Format
    6. 4. Implementing Total Count Calculation
    7. 5. Handling Empty Results
    8. Example: Empty page
    9. 6. Designing Default Page Sizes
    10. 7. Implementing Sorting with Pagination
    11. 8. Using HATEOAS Links
    12. Example: Page links
    13. 9. Handling Large Datasets
    14. 10. Implementing Search with Pagination
    15. 11. Implementing Pagination Metadata
    16. 12. Implementing Consistent Pagination

  25. Implementing API Documentation

    1. 1. Implementing OpenAPI Annotations
    2. Example: springdoc-openapi
    3. 2. Documenting Request/Response Examples
    4. Example: @ExampleObject
    5. 3. Documenting Authentication
    6. Example: Security scheme
    7. 4. Documenting Schema Definitions
    8. 5. Documenting Error Responses
    9. Example: Common error responses
    10. 6. Implementing Code Generation Configuration
    11. 7. Using Documentation Annotations
    12. 8. Implementing Custom Documentation Generators
    13. 9. Implementing Documentation Versioning
    14. 10. Implementing Interactive Documentation
    15. 11. Documenting API Rate Limits
    16. Example: Rate-limit docs
    17. 12. Documenting Deprecation Notices

  26. Designing Error Handling

    1. 1. Creating Custom Exception Hierarchies
    2. Example: Domain exceptions
    3. 2. Implementing Global Exception Handlers
    4. Example: @RestControllerAdvice
    5. 3. Designing Error Response Format
    6. 4. Implementing Exception Translation
    7. 5. Implementing Circuit Breaker Pattern
    8. Example: Resilience4j
    9. 6. Handling Validation Errors
    10. Example: Field error mapping
    11. 7. Logging Exceptions Appropriately
    12. 8. Implementing Retry Logic
    13. Example: Resilience4j retry
    14. 9. Designing Fallback Mechanisms
    15. 10. Using Result Objects vs Exceptions
    16. Exceptions
    17. Result<T,E>
    18. 11. Implementing Error Codes
    19. 12. Implementing Correlation IDs
    20. Example: Servlet filter

  27. Implementing Authentication Mechanisms

    1. 1. Designing User Authentication Flow
    2. 2. Implementing JWT Generation and Validation
    3. Example: Generate and verify (jjwt)
    4. 3. Implementing Session Management
    5. 4. Implementing OAuth 2.0 Client
    6. 5. Designing Password Storage
    7. Example: Spring Security PasswordEncoder
    8. 6. Implementing Multi-Factor Authentication
    9. 7. Implementing API Key Validation
    10. 8. Implementing SSO Integration
    11. 9. Handling Token Refresh Logic
    12. Example: Refresh endpoint
    13. 10. Implementing Authentication Filters
    14. 11. Implementing Remember Me Logic
    15. 12. Implementing Account Lockout

  28. Implementing Authorization Logic

    1. 1. Implementing Role-Based Access Control (RBAC)
    2. Example: Spring Security check
    3. 2. Implementing Attribute-Based Access Control (ABAC)
    4. 3. Designing Permission Checking Logic
    5. Example: Permission service
    6. 4. Implementing Resource-Level Authorization
    7. 5. Using Authorization Annotations
    8. 6. Implementing Policy-Based Authorization
    9. Example: OPA Rego policy
    10. 7. Implementing Hierarchical Roles
    11. Example: Role hierarchy (Spring)
    12. 8. Handling Dynamic Permissions
    13. 9. Implementing Method-Level Security
    14. 10. Implementing Claim-Based Authorization
    15. Example: JWT claim check
    16. 11. Implementing Permission Caching
    17. 12. Implementing Authorization Audit Trail

  29. Implementing API Security

    1. 1. Implementing Input Sanitization
    2. 2. Implementing CORS Configuration
    3. Example: Spring CORS
    4. 3. Implementing Security Headers
    5. 4. Implementing Request Signing Validation
    6. Example: HMAC signature
    7. 5. Implementing IP Whitelisting Logic
    8. 6. Implementing Audit Logging
    9. 7. Implementing Sensitive Data Handling
    10. 8. Implementing API Key Validation
    11. 9. Implementing Request/Response Encryption
    12. 10. Implementing Security Filters
    13. 11. Implementing CSRF Protection
    14. 12. Implementing Rate Limiting for Security

  30. Implementing Rate Limiting Logic

    1. 1. Implementing Token Bucket Algorithm
    2. Example: Bucket4j
    3. 2. Implementing Leaky Bucket Algorithm
    4. 3. Implementing Fixed Window Counter
    5. 4. Implementing Sliding Window Log
    6. 5. Implementing Rate Limit Scopes
    7. 6. Implementing Rate Limit Storage
    8. 7. Implementing Rate Limit Headers (X-RateLimit-*)
    9. 8. Implementing Rate Limit Exceeded Handler
    10. Example: 429 response
    11. 9. Implementing Dynamic Rate Limits
    12. 10. Implementing Rate Limit Bypass Logic
    13. 11. Implementing Sliding Window Counter
    14. 12. Implementing Distributed Rate Limiting
    15. Example: Redis token bucket (atomic Lua)

  31. Implementing Idempotency Logic

    1. 1. Understanding Idempotent Operations
    2. 2. Implementing Idempotency Key Validation
    3. 3. Implementing Idempotency Key Storage
    4. 4. Implementing Idempotent POST Handler
    5. Example: Handler flow
    6. 5. Implementing Response Caching
    7. 6. Implementing Retry-Safe Operations
    8. 7. Implementing Idempotency Token Expiration
    9. 8. Implementing Natural Idempotency
    10. 9. Handling Concurrent Idempotent Requests
    11. 10. Implementing Idempotency Audit Trail
    12. 11. Implementing Idempotency Middleware
    13. Example: Spring filter
    14. 12. Implementing Payment Idempotency

  32. Implementing Caching Logic

    1. 1. Implementing Cache-Aside Pattern
    2. Example: Read-through
    3. 2. Implementing Write-Through Cache
    4. 3. Implementing Write-Behind Cache
    5. 4. Implementing Cache Invalidation Logic
    6. 5. Implementing In-Memory Caching
    7. Example: Caffeine
    8. 6. Implementing Distributed Caching
    9. 7. Implementing Cache Hierarchies
    10. 8. Implementing Cache Warming
    11. 9. Designing Cache Key Generation
    12. 10. Handling Cache Stampede
    13. 11. Using Cache Annotations
    14. Example: Spring Cache
    15. 12. Implementing Cache Metrics

  33. Implementing Logging

    1. 1. Implementing Structured Logging
    2. Example: SLF4J + JSON
    3. 2. Defining Log Levels
    4. 3. Implementing Correlation IDs
    5. 4. Using MDC for Context
    6. Example: MDC scoped context
    7. 5. Implementing Audit Logging
    8. 6. Implementing Exception Logging
    9. 7. Implementing Performance Logging
    10. Example: Timed operation
    11. 8. Implementing Request/Response Logging
    12. 9. Handling Sensitive Data in Logs
    13. 10. Implementing Log Rotation Configuration
    14. Example: Logback rolling policy
    15. 11. Implementing Log Aggregation
    16. 12. Implementing Log Sampling

  34. Implementing Configuration Management

    1. 1. Designing Configuration Hierarchy
    2. 2. Implementing Externalized Configuration
    3. 3. Using Environment-Specific Configs
    4. Example: Spring profiles
    5. 4. Implementing Configuration Encryption
    6. 5. Implementing Feature Flags
    7. Example: Flag check
    8. 6. Using Configuration Profiles
    9. 7. Implementing Dynamic Configuration Refresh
    10. 8. Implementing Configuration Validation
    11. Example: @ConfigurationProperties + @Validated
    12. 9. Using Environment Variables
    13. 10. Implementing Configuration Binding
    14. 11. Implementing Secret Management
    15. 12. Implementing Configuration Auditing

  35. Implementing Concurrency Control

    1. 1. Designing Thread-Safe Services
    2. 2. Implementing Synchronization Mechanisms
    3. 3. Using Concurrent Data Structures
    4. 4. Implementing Async Processing
    5. Example: Spring @Async
    6. 5. Implementing Idempotency Keys
    7. 6. Handling Race Conditions
    8. 7. Designing Deadlock Prevention
    9. 8. Implementing Thread Pools
    10. Example: Bounded executor
    11. 9. Using Reactive Programming
    12. 10. Implementing Read-Write Locks
    13. Example: ReentrantReadWriteLock
    14. 11. Implementing Semaphores
    15. Example: Concurrency limit
    16. 12. Implementing Lock-Free Algorithms

  36. Implementing Event Handling

    1. 1. Designing Domain Events
    2. Example: Domain event record
    3. 2. Implementing Event Publisher
    4. Example: Spring ApplicationEventPublisher
    5. 3. Implementing Event Subscriber
    6. Example: @EventListener
    7. 4. Implementing Event Bus
    8. 5. Handling Async Event Processing
    9. 6. Implementing Event Sourcing
    10. 7. Implementing Event Replay
    11. Example: Rebuild aggregate
    12. 8. Designing Event Schema
    13. 9. Implementing Event Versioning
    14. 10. Handling Event Ordering
    15. 11. Implementing Event Deduplication
    16. 12. Implementing Event Audit Trail

  37. Implementing Message Queue Logic

    1. 1. Designing Message Producer
    2. Example: Kafka producer
    3. 2. Designing Message Consumer
    4. Example: @KafkaListener
    5. 3. Implementing Message Acknowledgment
    6. 4. Implementing Dead Letter Queues
    7. 5. Implementing Message Retry Logic
    8. Example: Spring Retry on consumer
    9. 6. Designing Message Format
    10. 7. Implementing Message Routing
    11. 8. Implementing Topic Subscription
    12. 9. Handling Message Ordering
    13. 10. Implementing Message Persistence
    14. 11. Implementing Producer Retry Logic
    15. 12. Implementing Consumer Group Management

  38. Implementing Background Job Processing

    1. 1. Designing Job Queue System
    2. 2. Implementing Scheduled Jobs
    3. Example: @Scheduled cron
    4. 3. Implementing Cron Job Processor
    5. 4. Implementing Job Scheduling Logic
    6. 5. Handling Job Failures
    7. 6. Implementing Job Retry Logic
    8. 7. Implementing Distributed Job Locks
    9. Example: ShedLock
    10. 8. Implementing Job Priority Queues
    11. 9. Implementing Job Status Tracking
    12. 10. Implementing Long-Running Job Logic
    13. 11. Handling Job Concurrency
    14. 12. Implementing Job Result Storage

  39. Implementing Serialization/Deserialization

    1. 1. Implementing JSON Serialization
    2. Example: Jackson ObjectMapper
    3. 2. Implementing Custom Serializers
    4. Example: Money serializer
    5. 3. Handling Date/Time Serialization
    6. 4. Handling Polymorphic Types
    7. Example: Sealed + JsonTypeInfo
    8. 5. Implementing Deep Copy Logic
    9. 6. Implementing Field Filtering
    10. 7. Handling Null Values
    11. 8. Implementing Versioned DTOs
    12. 9. Handling Circular References
    13. 10. Implementing Schema Validation
    14. 11. Handling Binary Data
    15. 12. Implementing Compression

  40. Implementing File Upload Logic

    1. 1. Implementing Multipart Upload Handler
    2. Example: Spring MultipartFile
    3. 2. Implementing File Validation
    4. 3. Implementing Storage Logic
    5. 4. Implementing Chunked Upload
    6. 5. Implementing Resume Upload Logic
    7. 6. Handling Large File Uploads
    8. 7. Implementing Virus Scanning
    9. 8. Implementing Image Processing
    10. 9. Implementing Cloud Storage Integration
    11. Example: AWS S3 PutObject
    12. 10. Implementing Pre-Signed URLs
    13. Example: Pre-signed PUT
    14. 11. Implementing Upload Progress Tracking
    15. 12. Implementing File Deletion Logic

  41. Implementing Search Functionality

    1. 1. Implementing Basic Search Logic
    2. Example: SQL LIKE search
    3. 2. Implementing Full-Text Search
    4. Example: PostgreSQL tsvector
    5. 3. Implementing Search Indexing
    6. 4. Implementing Search Filters
    7. 5. Implementing Search Pagination
    8. 6. Implementing Search Ranking
    9. 7. Implementing Faceted Search
    10. Example: Elasticsearch aggregations
    11. 8. Implementing Auto-Complete
    12. 9. Implementing Search Suggestions
    13. 10. Implementing Search Result Highlighting
    14. Example: Elasticsearch highlight
    15. 11. Implementing Search Analytics
    16. 12. Integrating Search Engines (Elasticsearch)

  42. Implementing Notification Logic

    1. 1. Designing Notification System Architecture
    2. 2. Implementing Email Notifications
    3. Example: Spring JavaMailSender
    4. 3. Implementing SMS Notifications
    5. 4. Implementing Push Notifications
    6. 5. Implementing In-App Notifications
    7. 6. Implementing Notification Templates
    8. Example: Thymeleaf email template
    9. 7. Implementing Notification Preferences
    10. 8. Implementing Notification Queuing
    11. 9. Implementing Delivery Tracking
    12. 10. Implementing Retry Logic for Failed Notifications
    13. 11. Implementing Notification Batching
    14. 12. Implementing Multi-Channel Notifications

  43. Implementing Webhook Logic

    1. 1. Designing Webhook Subscription System
    2. 2. Implementing Webhook Delivery Logic
    3. Example: Async POST
    4. 3. Implementing Webhook Signing
    5. Example: HMAC-SHA256
    6. 4. Implementing Webhook Verification (Server)
    7. 5. Implementing Retry Logic with Exponential Backoff
    8. 6. Implementing Webhook Delivery Tracking
    9. 7. Implementing Webhook Failure Handling
    10. 8. Implementing Webhook Event Filtering
    11. 9. Implementing Webhook Replay
    12. 10. Implementing Webhook Security
    13. 11. Implementing Webhook Rate Limiting
    14. 12. Implementing Webhook Logging

  44. Implementing Data Export

    1. 1. Implementing CSV Export
    2. Example: Streaming CSV
    3. 2. Implementing Excel Export
    4. 3. Implementing PDF Export
    5. 4. Implementing JSON Export
    6. Example: Streaming JSON array
    7. 5. Implementing Streaming Export for Large Datasets
    8. 6. Implementing Async Export Generation
    9. 7. Implementing Export Format Selection
    10. 8. Implementing Export Compression
    11. 9. Implementing Export Pagination
    12. 10. Handling Export Field Selection
    13. 11. Implementing Export Scheduling
    14. 12. Implementing Export Audit Trail

  45. Implementing Bulk Operations

    1. 1. Designing Bulk API Endpoints
    2. 2. Implementing Bulk Insert Logic
    3. Example: JDBC batch
    4. 3. Implementing Bulk Update Logic
    5. Example: Set-based UPDATE
    6. 4. Implementing Bulk Delete Logic
    7. 5. Implementing Bulk Import from CSV
    8. Example: Streaming CSV reader
    9. 6. Implementing Bulk Export
    10. 7. Handling Partial Failures
    11. 8. Implementing Bulk Operation Progress
    12. 9. Implementing Bulk Operation Validation
    13. 10. Implementing Bulk Operation Rollback
    14. 11. Implementing Bulk Operation Throttling
    15. 12. Implementing Bulk Operation Reporting

  46. Implementing Soft Delete Logic

    1. 1. Designing Soft Delete Schema
    2. 2. Implementing Soft Delete Filter
    3. Example: Hibernate @SQLRestriction
    4. 3. Implementing Restore Logic
    5. Example: Restore endpoint
    6. 4. Handling Cascade Soft Deletes
    7. 5. Implementing Hard Delete Logic
    8. 6. Implementing Soft Delete Audit
    9. 7. Handling Unique Constraints with Soft Delete
    10. 8. Implementing Soft Delete Queries
    11. 9. Implementing Permanent Delete After Period
    12. Example: Cleanup job
    13. 10. Handling Soft Delete in Joins
    14. 11. Implementing Soft Delete Indicators
    15. 12. Implementing Bulk Soft Delete
    16. Example: Bulk update

  47. Implementing Multi-Tenancy

    1. 1. Designing Multi-Tenancy Architecture
    2. 2. Implementing Tenant Identification
    3. 3. Implementing Database Isolation Strategies
    4. 4. Implementing Schema Per Tenant
    5. Example: Hibernate MultiTenantConnectionProvider
    6. 5. Implementing Database Per Tenant
    7. 6. Implementing Shared Schema with Tenant ID
    8. Example: Postgres Row-Level Security
    9. 7. Implementing Tenant Context Propagation
    10. Example: Filter + ThreadLocal holder
    11. 8. Implementing Tenant-Specific Configuration
    12. 9. Implementing Cross-Tenant Operations
    13. 10. Implementing Tenant Provisioning
    14. 11. Implementing Tenant Migration Logic
    15. 12. Implementing Tenant Resource Limits

  48. Implementing Internationalization (i18n)

    1. 1. Implementing Message Bundles
    2. Example: messages_en.properties
    3. 2. Implementing Locale Detection
    4. 3. Implementing Translation Lookup
    5. Example: Spring MessageSource
    6. 4. Handling Pluralization
    7. Example: ICU plural
    8. 5. Implementing Date/Time Localization
    9. Example: java.time formatters
    10. 6. Implementing Number/Currency Localization
    11. Example: Currency format
    12. 7. Implementing Right-to-Left Support
    13. 8. Implementing Locale-Specific Validation
    14. 9. Implementing Translation Caching
    15. 10. Implementing Fallback Locale Logic
    16. 11. Implementing Dynamic Language Switching
    17. Example: LocaleChangeInterceptor
    18. 12. Implementing Translation Management

  49. Implementing Real-Time Features

    1. 1. Implementing WebSocket Connections
    2. Example: Spring @MessageMapping
    3. 2. Implementing Server-Sent Events
    4. Example: SSE endpoint
    5. 3. Implementing Long Polling
    6. 4. Implementing Message Broadcasting
    7. 5. Handling Connection Lifecycle
    8. 6. Implementing Authentication for WebSockets
    9. 7. Implementing Presence Tracking
    10. 8. Implementing Real-Time Notifications
    11. 9. Implementing Pub/Sub Pattern
    12. Example: Redis pub/sub
    13. 10. Handling Reconnection Logic
    14. 11. Implementing Message Queuing for Offline Users
    15. 12. Implementing Real-Time Event Filtering

  50. Implementing Service-to-Service Communication

    1. 1. Implementing REST Client Logic
    2. Example: Spring RestClient (modern)
    3. 2. Implementing gRPC Client/Server
    4. Example: Server stub
    5. 3. Implementing Service Discovery Logic
    6. 4. Implementing Load Balancing Logic
    7. 5. Implementing Circuit Breaker for External Calls
    8. Example: Resilience4j
    9. 6. Implementing Retry Logic for Service Calls
    10. 7. Implementing Service Mesh Patterns
    11. 8. Implementing API Gateway Communication
    12. 9. Implementing Saga Pattern
    13. 10. Implementing Event-Driven Communication
    14. 11. Implementing Synchronous vs Asynchronous
    15. Sync (REST/gRPC)
    16. Async (Queue/Event)
    17. 12. Implementing Service Versioning

  51. Implementing Aspect-Oriented Programming

    1. 1. Implementing Logging Aspects
    2. Example: Method entry/exit logger
    3. 2. Implementing Performance Monitoring Aspects
    4. Example: Micrometer timer
    5. 3. Implementing Security Aspects
    6. 4. Implementing Transaction Aspects
    7. 5. Implementing Caching Aspects
    8. 6. Implementing Audit Aspects
    9. Example: @Auditable
    10. 7. Implementing Validation Aspects
    11. 8. Implementing Exception Handling Aspects
    12. Example: @AfterThrowing
    13. 9. Designing Pointcut Expressions
    14. 10. Implementing Around Advice
    15. 11. Implementing Custom Annotations
    16. Example: Marker annotation
    17. 12. Implementing Cross-Cutting Concerns

  52. Implementing Reactive Programming

    1. 1. Implementing Reactive Streams
    2. 2. Using Mono and Flux
    3. Example: Project Reactor
    4. 3. Implementing Reactive Operators
    5. 4. Handling Backpressure
    6. 5. Implementing Reactive Repositories
    7. Example: R2DBC repository
    8. 6. Implementing Reactive Web Controllers
    9. Example: WebFlux
    10. 7. Handling Reactive Error Handling
    11. 8. Implementing Reactive Composition
    12. Example: Combine sources
    13. 9. Implementing Reactive Testing
    14. Example: StepVerifier
    15. 10. Handling Schedulers
    16. 11. Implementing Reactive Caching
    17. 12. Implementing Reactive Security

  53. Implementing Performance Optimization

    1. 1. Implementing Database Query Optimization
    2. 2. Implementing Caching Strategies
    3. 3. Implementing Connection Pooling
    4. 4. Implementing Async Processing
    5. 5. Implementing Lazy Loading
    6. 6. Implementing Pagination Optimization
    7. Example: Keyset pagination
    8. 7. Implementing Database Indexing Strategy
    9. 8. Implementing Response Compression
    10. 9. Implementing Resource Pooling
    11. 10. Implementing Memory Optimization
    12. 11. Implementing CPU Optimization
    13. 12. Implementing Network Optimization

  54. Implementing Code Quality Practices

    1. 1. Implementing Code Reviews
    2. 2. Implementing Static Analysis
    3. 3. Implementing Code Coverage
    4. 4. Implementing Linting Rules
    5. 5. Implementing Documentation Standards
    6. 6. Implementing Code Formatting
    7. Example: Spotless config (Gradle)
    8. 7. Implementing Code Complexity Limits
    9. 8. Implementing Refactoring Patterns
    10. 9. Implementing Technical Debt Tracking
    11. 10. Implementing Best Practices
    12. 11. Implementing Code Smells Detection
    13. 12. Implementing Code Metrics

  55. Implementing Testing Strategies

    1. 1. Designing Unit Tests
    2. Example: JUnit 5 + AssertJ
    3. 2. Implementing Integration Tests
    4. 3. Implementing End-to-End Tests
    5. 4. Implementing Mock Objects
    6. Example: Mockito
    7. 5. Implementing Test Doubles
    8. 6. Implementing Test Data Builders
    9. Example: Builder for tests
    10. 7. Implementing Database Test Strategies
    11. 8. Implementing Performance Tests
    12. 9. Implementing Security Tests
    13. 10. Implementing Contract Tests
    14. 11. Implementing Test Coverage Goals
    15. 12. Implementing Test Automation in CI/CD