Modulith Instead of Monolith - Pragmatically Towards Microservices

Is there a middle ground between monoliths and microservices? Discover the modulith, a pattern for modernizing legacy systems without unnecessary complexity.

#1about 3 minutes

Analyzing a complex 20-year-old legacy system

The initial state of a hardware control application was not a simple monolith but a messy mix of C# WinForms and C++ services.

#2about 2 minutes

Why traditional monoliths get a bad reputation

Unplanned monoliths often lead to tangled dependencies, deployment challenges, scaling issues, and code that is difficult to understand or modify.

#3about 4 minutes

Defining the modulith as a pragmatic alternative

A modulith combines the deployment simplicity of a monolith with the organizational benefits of modules based on business-bounded contexts.

#4about 3 minutes

Contrasting modulith and microservice architectures

While microservices offer independent deployment, a modulith optimizes for a single runtime environment, reducing network overhead and improving resource efficiency.

#5about 4 minutes

Designing modules with clear public interfaces

Modules are built around a domain model with public interfaces, allowing internal implementations to be swapped without affecting other parts of the system.

#6about 3 minutes

Managing product line complexity with modules

A modular architecture simplifies support for multiple product generations and hardware variations by enabling interchangeable component implementations.

#7about 6 minutes

Structuring the application with a layered architecture

The system is organized into distinct layers for hardware, assets (domain entities), features, and product configuration, all built on a shared foundation platform.

#8about 4 minutes

Executing an incremental refactoring to a modulith

The refactoring process involves wrapping the legacy system as the first module and then systematically extracting new, independent modules based on domain models.