Designs

 Most good programmers do programming not because they expect to get paid or get adulation by the public, but because it is fun to program. - Linus Torvalds

Real-world designs

• Design a business validator framework
• Design a business mini-rule engine
• Design an email library
• Design an iCalendar library
• Design a meeting scheduler
• Design a report sender
• Design practical REST APIs
  

Case study

• How to handle concurrent reservations?
• Design a unique sequence with MongoDB
• Base62 encoding with Java
• How to design a URL shortener?
• Effective Strategies for Handling External Services

Architecture

• Hexagonal architecture
• Domain-driven design
• Message broker
• Pipes and filters
• Plugin architecture
• Layered architecture

Design Patterns

• Rules design pattern 
• Breaking if/else with a chain
• Batch processing with an iterator

Mixed

• Do not use magic in unit tests
• Split your loop
• Replace HashTable with Map
• Do not judge a design by Sonar coverage
• Why you should not use field injection
• The tail of list.remove()