1. AND ITS LOGIC
MIND YOUR BUSINESS

2. Vladik Khononov
Chief Architect @ Internovus
@vladikk
http://vladikk.com

3. BUSINESS LOGIC

4. PRESENTATION LAYER
BUSINESS LOGIC LAYER
DATA ACCESS LAYER

5. 💵

6. PRESENTATION LAYER
BUSINESS LOGIC LAYER
DATA ACCESS LAYER

7. Transaction Script
Active Record
Domain Model
Event Sourced Domain Model

8. TRANSACTION SCRIPT

9. TRANSACTION SCRIPT
▸ Simple Business Logic
▸ CRUD
▸ Input Validation
▸ Extract Transform Load (ETL)
▸ Simple Data Structures
▸ Always leave the database in a consistent state

10.
APPLICATIONCREATE USER UPDATE USER SEARCH USERS
DATABASE
UI

11. public class CreateUser {
public void Execute(name, email) {
try {
DB.StartTransaction();
var row = DB.NewUserRow();
row.Name = name;
row.Email = email;
DB.Append(row);
DB.Commit();
} catch {
DB.Rollback();
throw;
}
}
}

12. ACTIVE RECORD

13. ACTIVE RECORD
▸ Simple Business Logic
▸ CRUD
▸ Input Validation
▸ Extract Transform Load (ETL)
▸ Complex Data Structures
▸ References / Collections
▸ Multiple Tables

14. USER INTERESTS
ID
NAME Has
many
ADDRESSCOUNTRY CITY
STREET

15.
APPLICATIONCREATE USER UPDATE USER SEARCH USERS
DATABASE
UI

16.
APPLICATIONCREATE USER UPDATE USER SEARCH
USERS
UI
ACTIVE
RECORDS
USER
DATABASE

17. public class CreateUser {
public void Execute(userDetails) {
try {
DB.StartTransaction();
var user = new User();
user.Name = userDetails.Name;
user.Email = userDetails.Email;
user.Save();
DB.Commit();
} catch {
DB.Rollback();
throw;
}
}
}

18. public class User {
public Guid Id { get; set; }
public string Name { get; set; }
public List<Interest> Interests { get; set; }
public Address Address { get; set; }
public void Save() { … }
public void Delete() { … }
public static User Get(Guid id) { … }
public static List<User> GetAll() { … }
}

19. DOMAIN MODEL

20. DOMAIN MODEL
▸ Complex Business Logic
▸ Business rules
▸ Invariants
▸ Calculations
▸ Complex algorithms

21.
APPLICATIONCREATE USER UPDATE USER SEARCH
USERS
UI
ACTIVE
RECORDS
USER
DATABASE

22.
APPLICATIONCREATE USER UPDATE USER SEARCH USERS
UI
DOMAIN
MODEL
USER
DATABASE

23.
APPLICATIONCREATE USER UPDATE USER SEARCH USERS
UI
DOMAIN
MODEL
USER
INFRASTRUCTURE

24. DOMAIN MODEL
▸ Complex business logic
▸ Model business domain
▸ Objects: data + behavior
▸ Plain objects
▸ Minimal application level use cases

25. public class UpdateUser {
public void Execute(userDetails) {
try {
var user = usersRepository.Get(userDetails.Id);
user.UpdateDetails(userDetails);
usersRepository.Save(user);
} catch {
DB.Rollback();
throw;
}
}
}

26. public class User {
public Guid Id { get; private set; }
public string Name { get; private set; }
public List<Interest> Interests { get; private set; }
public Address Address { get; private set; }
public void UpdateDetails() { … }
public void AddInterest() { … }
public static User InitializeNew() { … }
}
public interface IUsersRepository {
User Get(Guid id);
void Save(User user);
void Delete(User user);
}

27.
APPLICATIONCREATE USER UPDATE USER SEARCH USERS
UI
DOMAIN
MODEL
USER
INFRASTRUCTURE

28. EVENT SOURCED
DOMAIN MODEL

29. EVENT SOURCED DOMAIN MODEL
▸ Complex Business Logic
▸ Business rules
▸ Invariants
▸ Complex algorithms
▸ Deals w/ money
▸ Data analysis required
▸ Audit required by law

30. EVENT SOURCED DOMAIN MODEL
PhoneEmailNameId
46464543one@gmail.comJames1
34234343two@gmail.comJohn2

31. public class NewUserInitialized {
public Guid UserId { get; private set; }
public string Name { get; private set; }
public string Email { get; private set; }
}
public class NameChanged {
public Guid UserId { get; private set; }
public string NewName { get; private set; }
}
public class EmailChanged {
public Guid UserId { get; private set; }
public string NewEmail { get; private set; }
}

32. EVENT SOURCED DOMAIN MODEL
▸ UserInitialized(1, John, john@gmail.com)
▸ NameChanged(1, James)
▸ EmailChanged(1, james@gmail.com)

33.
APPLICATIONCREATE USER UPDATE USER SEARCH USERS
UI
DOMAIN
MODEL
USER
EVENT STORE

34. Transaction Script
Active Record
Domain Model
Event Sourced Domain Model

35. APPLICATION
ARCHITECTURE

36. LAYERED ARCHITECTURE
PRESENTATION LAYER
BUSINESS LOGIC LAYER
DATA ACCESS LAYER

37. HEXAGONAL / PORTS & ADAPTERS / ONION / CLEAN ARCHITECTURE
CORE
SERVICES
INFRASTRUCTURE

38. CQRS - COMMAND QUERY RESPONSIBILITY SEGREGATION
WRITE MODEL
COMMANDS
UI
READ MODEL
QUERIES

39. «SHLIKHTA» ARCHITECTURE
EVERYTHING

40. EVENT SOURCED DOMAIN MODEL
• Shlikhta Architecture
• Layered Architecture
• Hexagonal Architecture
• CQRS
• Transaction Script
• Active Record
• Domain Model
• Event Sourced Domain Model

41. TESTING
STRATEGIES

42. TESTS PYRAMID
UI
/
End to End
Service / API
layer tests
Unit Tests

43. TESTS PYRAMID
UI
/
End to End
Service / API
layer tests
Unit Tests

44. TESTS PYRAMID
UI
/
End to End
Service / API
layer tests
Unit Tests

45. TESTS PYRAMID
UI
/
End to End
Service / API
layer tests
Unit Tests

46. TESTING STRATEGIES
• End to end tests
• API layer tests
• Unit tests
• Unit tests
• Transaction Script
• Active Record
• Domain Model
• Event Sourced Domain Model

47. LANGUAGE AND
TECHNOLOGY

48. PROGRAMMING STYLE
• Procedural
• Procedural / OOP
• OOP
• Functional
• Transaction Script
• Active Record
• Domain Model
• Event Sourced Domain Model

49. DYNAMIC / STATIC TYPING
• Dynamic
• Dynamic
• Static
• Static
• Transaction Script
• Active Record
• Domain Model
• Event Sourced Domain Model

50. RAMIFICATIONS
▸ Architectural style / pattern
▸ Testing strategy
▸ Language and technology
▸ Programming style
▸ Language type

51. DECISION HEURISTIC
▸ Is the business logic mostly CRUD / ETL? Yes
▸ Are the data structures simple? yes - Transaction Script
▸ Are the data structures simple? No -Active Record
▸ Is the business logic mostly CRUD / ETL? No
▸ Is advanced analysis required, or dealing w/ money? No
Domain Model
▸ Is advanced analysis required, or dealing w/ money? Yes
Event Sourced Domain Model

52. TRANSACTION SCRIPT
ACTIVE RECORD
DOMAIN MODEL
EVENT SOURCED DOMAIN MODEL

53. AGILE ARCHITECTURE

54. TRANSACTION SCRIPT / SHLIKHTA
ACTIVE RECORD / LAYERS
DOMAIN MODEL / HEXAGONAL
EVENT SOURCED DOMAIN MODEL / CQRS

55. DECISION SCOPE

56. CAMPAIGN MANAGEMENT LEAD MANAGEMENT

57.
CAMPAIGN MANAGEMENT
LEAD MANAGEMENT
CREATIVE CATALOG
CAMPAIGN PUBLISHING
BILLING
USERS MANAGEMENT
SALES
COMMISSIONS CALCULATION
DESK MANAGEMENT
VOIP MANAGEMENT

58. SUMMARY

59. Business Driven Architecture

61. QUESTIONS?

62. THANK YOU
Vladik Khononov
Chief Architect @ Internovus
@vladikk
http://vladikk.com