Taming Microservice Overload: Our Journey to Modular Monoliths
Conference (INTERMEDIATE level)
Zaal 12
At the Port of Rotterdam, our system had grown into far more microservices than our teams could effectively own. The result: operational overhead, fragmented domain knowledge, and an overgrown architecture that was hard to maintain and evolve.
In this session, I’ll share how we combined Domain-Driven Design (DDD) with Spring Modulith to consolidate our microservices into a smaller set of modular monoliths. Each microservice represents a bounded context, with modules organized around distinct business capabilities, preserving clear domain boundaries while reducing operational complexity.
You’ll learn:
If your microservices landscape has outgrown your teams, this talk shows how modular monoliths can restore clarity, ownership, and long-term maintainability, without compromising architectural integrity.
In this session, I’ll share how we combined Domain-Driven Design (DDD) with Spring Modulith to consolidate our microservices into a smaller set of modular monoliths. Each microservice represents a bounded context, with modules organized around distinct business capabilities, preserving clear domain boundaries while reducing operational complexity.
You’ll learn:
- How to define and model business domains and bounded contexts using DDD
- How to implement these domains as modular monoliths with Spring Modulith
- How Spring Modulith keeps your modules clean and maintainable
- Common pitfalls we encountered and how we solved them
If your microservices landscape has outgrown your teams, this talk shows how modular monoliths can restore clarity, ownership, and long-term maintainability, without compromising architectural integrity.
Mario Klaver
Port of Rotterdam
Mario Klaver is a Solution Architect at the Port of Rotterdam, where he is responsible for the digital systems supporting Harbour Master operations. With a background in Java and Kotlin development, he focuses on building clean, modular software architectures for mission-critical environments. Combining hands-on engineering experience with a pragmatic approach to architecture, Mario Klaver helps teams design systems that are scalable, understandable, and built to last — even under 24/7 operational demands.