Nowadays, many companies are faced with the challenge of modernising their ageing applications, making them more flexible and structuring them appropriately. While microservices are widely used, a modulith - modular structured monolith - offers a promising alternative that is often overlooked.

This presentation provides insight into the practical work with Moduliths and the migration to them. We will also talk about experiences with suitable technologies such as Spring Modulith, xMolecules, ArchUnit and jQAssistant and discuss what to look out for when using them.

We will also discuss the advantages and challenges of the transformation to microservices. We look at aspects such as implementation effort, impact on the existing source code, fundamental risks in long-running replacement projects, test strategies, cognitive load, dependencies at business and technical level and the effects that all these topics have in practice.

Overall, the presentation offers an experience-based overview of Modulithen and is aimed at software architects, developers and IT decision-makers who are dealing with the modernisation of their existing systems.