Monolith (Traditional)

A Monolithic architecture is built as a single unit. All functional components (UI, Business Logic, Data Access) are tightly integrated using a shared database and running in the same process.

When to Use

Proof of Concept (PoC) or MVP.
Very small teams (< 5 developers).
Simple CRUD applications with low complexity.
When latency must be absolute zero and throughput is not the bottleneck.

Quick Start

# Django/Rails/Laravel Style
# Everything in one place:
# - models/
# - views/
# - controllers/
# - utils/

def create_order(request):
    user = User.objects.get(id=request.user_id) # Direct DB access
    product = Product.objects.get(id=request.product_id) # Direct DB access

    order = Order.create(user=user, product=product)

    # Direct sync call within same transaction
    EmailService.send_confirmation(user)

    return Response("Order Created")

Core Concepts

Single Process

The entire app runs in one memory space. Scaling means "Vertical Scaling" (bigger server) or "Horizontal Scaling" (cloning the entire monolith behind a load balancer).

Shared Database

All components read/write to the same massive database. JOINs across any domains are easy and performant.

Simplicity

One repo, one build pipeline, one deploy script. Infinite ease of debugging (step through everything).

Common Patterns

Layered Architecture

Even in a monolith, organize by technical layers (Presentation, Business, Data) to prevent spaghetti code.

"Big Ball of Mud" (Anti-pattern)

The chaotic state a monolith reaches without discipline, where everything depends on everything else.

Best Practices

Do:

Keep code clean and modular (files/folders) even if deployment is monolithic.
Use Feature Flags to manage releases.
Optimize Database Queries early, as the single DB is the bottleneck.

Don't:

Don't let the build time exceed 10-15 minutes (split if it does).
Don't allow "Spaghetti Coupling" (Circular dependencies).

References

Martin Fowler - MonolithFirst