NEW BOOK

Pragmatic DDD with Python

AI will love your code

Master Domain-Driven Design, CQRS, and Hexagonal Architecture with practical Python and FastAPI examples.

Pragmatic DDD with Python Book Cover

Why DDD Matters

Most Python applications start simple but become unmaintainable spaghetti as they grow. Business logic scattered across routes, models, and services. Changes in one place break things elsewhere.

Domain-Driven Design gives you patterns to organize complexity—and AI tools can understand and extend well-structured code.

What You'll Learn

DDD Building Blocks

Entities, Value Objects, Aggregates, Repositories—implement them properly in Python without over-engineering.

CQRS Pattern

Separate reads from writes. Commands, Queries, and Handlers that scale and test beautifully.

Hexagonal Architecture

Ports and Adapters that keep your domain pure. Swap databases, APIs, or frameworks without rewriting business logic.

AI-READY CODE

Why AI Will Love Your Code

Well-structured DDD code isn't just for humans. AI coding assistants understand and extend clean architectures better than spaghetti code.

Clear boundaries = precise AI modifications
Consistent patterns = predictable suggestions
Explicit rules = fewer hallucinations

# AI understands this structure:

@dataclass

class Booking(AggregateRoot):

items: list[BookingItem] = field(default_factory=list)

status: BookingStatus = BookingStatus.PENDING

def add_item(self, product: Product, quantity: int) -> None:

if self.status != BookingStatus.PENDING:

raise CannotModifyConfirmedBooking()

self.items.append(BookingItem(product, quantity))

def confirm(self) -> None:

if self.total_amount() < self.minimum_spend:

raise MinimumSpendNotReached()

self.status = BookingStatus.CONFIRMED

38 Chapters of Practical DDD

From fundamentals to advanced patterns. Real code, real examples, real Python.

PART I-II

Foundations

Why DDD, the three pillars, folder structure, entities, value objects, aggregates.

PART III-IV

Application Layer

Commands, queries, handlers, DTOs, repositories, domain events, external integrations.

PART V-VI

Testing & Contexts

Unit testing, integration testing, bounded contexts, context mapping, external systems.

PART VII-IX

Advanced & AI

Event sourcing, CQRS deep dive, projections, real-world patterns, AI-assisted development.

38

Chapters

15+

Diagrams

100+

Code Examples

4

Appendices

Who Is This Book For?

If you build Python applications and want them to scale without becoming unmaintainable, this book is for you.

Python Developers

Move beyond basic patterns. Learn architecture that handles complexity without fighting the framework.

Tech Leads

Establish architecture patterns your team can follow. Make code reviews easier with clear boundaries.

AI-Forward Teams

Structure code so AI assistants can help effectively. Reduce hallucinations with explicit patterns.

What Readers Say

Early feedback from Python developers and architects.

"The AI argument completely reframes the 'too much boilerplate' objection. If AI writes the boilerplate, who cares?"
C

Carlos

Junior Python Developer

"This is the first DDD book I've read that feels like it was written by someone who ships on Fridays."
L

Laura

Tech Lead, 8 years experience

"For Python teams wanting structure beyond basic patterns, this fills a real gap. Best Python DDD guide available."
M

Miguel

DDD Architect, 15 years experience

"Best compromise for Python teams. The domain layer is truly framework-agnostic."
A

Andres

Clean Architecture Advocate

"The code examples are production-grade. Real Python 3.10+ code, not pseudocode. Finally validates modern DDD in Python."
P

Patricia

Senior Python Developer, 12 years

7.7

Average Rating

From 5 early reviewers

Ready to Master DDD with Python?

Get the book and start building maintainable, AI-friendly applications today.