SOFTWARE ARCHITECTURE: LAYERS,
COMPONENTS, AND DESIGN PATTERNS
EXAM QUESTIONS AND ANSWERS.
VERIFIED 2025/2026.
Presentation layer - ANS Handles user interaction such as screens menus routes and basic
formatting. Should not contain business rules or database code.
Controller - ANS Directs the user flow by reading input calling application services and
choosing what to show next.
View - ANS Displays information to the user such as console output web pages or UI widgets.
View model - ANS Data shaped for display so the UI can render easily without extra logic.
Presenter - ANS Prepares display ready text and values so views stay simple.
Input output helper - ANS Reusable code for reading and writing at the UI boundary such as
prompt read int and print.
Routing - ANS Maps user actions or URLs to controller handlers.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Request handler - ANS Receives an input event and calls the correct use case then returns a
response.
Response model - ANS Data shape returned to the UI that is safe to display.
Application layer - ANS Implements use cases which are the actions the system can perform.
Coordinates domain and data access.
Application service - ANS Implements a system action such as create habit or checkout.
Enforces business rules and calls repositories.
Use case - ANS A single user goal expressed as an operation such as create habit mark
completed or register user.
Interactor - ANS Another name for a use case class that performs one focused operation.
Command object - ANS Holds input data needed to run a use case without adding business
behavior.
Query object - ANS Holds input data needed to read information without changing state.
Business operation workflow - ANS The ordered steps that change system state such as
validate load update save.
Transaction boundary - ANS All or nothing unit of work for a use case when persistence is
involved.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
COMPONENTS, AND DESIGN PATTERNS
EXAM QUESTIONS AND ANSWERS.
VERIFIED 2025/2026.
Presentation layer - ANS Handles user interaction such as screens menus routes and basic
formatting. Should not contain business rules or database code.
Controller - ANS Directs the user flow by reading input calling application services and
choosing what to show next.
View - ANS Displays information to the user such as console output web pages or UI widgets.
View model - ANS Data shaped for display so the UI can render easily without extra logic.
Presenter - ANS Prepares display ready text and values so views stay simple.
Input output helper - ANS Reusable code for reading and writing at the UI boundary such as
prompt read int and print.
Routing - ANS Maps user actions or URLs to controller handlers.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Request handler - ANS Receives an input event and calls the correct use case then returns a
response.
Response model - ANS Data shape returned to the UI that is safe to display.
Application layer - ANS Implements use cases which are the actions the system can perform.
Coordinates domain and data access.
Application service - ANS Implements a system action such as create habit or checkout.
Enforces business rules and calls repositories.
Use case - ANS A single user goal expressed as an operation such as create habit mark
completed or register user.
Interactor - ANS Another name for a use case class that performs one focused operation.
Command object - ANS Holds input data needed to run a use case without adding business
behavior.
Query object - ANS Holds input data needed to read information without changing state.
Business operation workflow - ANS The ordered steps that change system state such as
validate load update save.
Transaction boundary - ANS All or nothing unit of work for a use case when persistence is
involved.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
