Concepts

Ubiquitous language

• use the same terms in code as the user use
• have common language between delivery team and actual people (aka customers)
  • helps to understand business by logic
  • helps with communication
• use real-world language in code

Aggregates

• a representatino of real domain concept
  • something like an Order, an Invoice, Stock Item
• aggregates typically have an information cycle around them
• in general
  • aggregate as something that has
    • state
    • identity
    • information cycle
      • that will be managed as part of the system
• aggregates can have relationships to other aggregates

Bounded context

• a larger organizational boundary
  • within it explicit responsibilities need to be carried out
• bounded contexts hide implementation details ()
• bounded contexts contain 1-n aggregates
  • some aggregates may be exposed outside the bounded context
  • others may be hidden internally

Event Storming

• collaborative brainstorming exercise designed to help design a domain model
• invented by Alberto Brandolini

Boundaries between microservices

• There are some factors when defining clear boundaries between Microservices
  • volatility
  • data
    • also with concern to security
  • technology
  • organizational
    • Layering Inside vs Layering Outside

Resources

• 2023-03-13 ◦ A gentle introduction to Domain Driven Design | by The Lone Architect | Medium
• 2022-12-01 ◦ Michael Plöd (@mploed) on Speaker Deck
  • Hands-on Domain-driven Design - by Example (on leanpub)
  • writes about DDD in general