Oliver Drotbohm

@odrotbohm.de

1340 Followers 142 Following

Frameworks & Architecture in the Spring open source engineering team, all things Spring, Java, data, DDD, REST, software architecture, drums & music. He/him.

Me and Jacques Villeneuve are standing together in an indoor setting, smiling at the camera. Me wearing a black Nike cap and a dark shirt, while he is dressed in a checked shirt over a t-shirt. Background features indoor plants and an emergency exit sign.
A large crowd gathers in Olympiastadion Berlin for a concert by the Foo Fighters, with a stage prominently featuring lights and equipment. The image captures the audience, many of whom are holding their phones, generating a sea of lights.
A computer screen showing a Logic project containing a few tracks of a Funk loop and the mix playing.
A large audience seated in a conference hall, facing a stage with a presenter under colorful lighting. Screens display "<CODE CRAFTS> 2026" alongside logos of various sponsors. The space features modern decor, with a vibrant purple hue enhancing the mood.
A store front of a closed down shop titled “Microservice GmbH Computer Verkauf”.
A group of workers is gathered in a residential area, one of them is digging in the ground while others observe. They are dressed in various work attire, including reflective jackets and hooded sweatshirts. One of them is looking at his mobile phone.
A person is standing behind a podium with digital screens and colorful graphics, illuminated by blue stage lights. The design includes the words "SPRING" and "2026," suggesting a tech or gaming event.
Werbung für die BahnCard 25 der Deutschen Bahn. Angepriesen werden 25 % Rabatt auf Preise des Fernverkehrs für Sparangebote.
The image features a panoramic view of the Bacelona skyline at sunset, with buildings and a mountainous background. The text "MAYMANTA ORIGEN PERÚ" is prominently displayed in the center.
A Calvin & Hobbes comic strip. Hobbes: “Do you have an idea for your story yet?“ Calvin: “No, I’m waiting for inspiration. You can’t just turn on creativity like a faucet. You have to be in the right mood.” Hobbes: “What mood is that?” Calvin: “Last-minute panic.”
An airplane is parked at an airport gate, connected to a jet bridge. Ground crew in high-visibility vests are working nearby. In the background, airport buildings and a control tower are visible under a cloudy sky.
An explanation of how to combine Spring Modulith’s application integration testing capabilities with Spring Boot’s horizontal slice tests.
An instructional document about Namastack Outbox support, detailing how to activate advanced outbox features. It includes a code snippet for declaring the Spring Modulith Namastack starter and instructions for configuring event externalization.
A large audience is seated in a tiered lecture hall, attentively listening to a speaker presenting on a screen that displays the title „Domain-centric? Why Hexagonal And Onion Architecture Are Answers to The Wrong Question – And What To Ask Instead?" The room features wooden walls and a modern design.
A Lufthansa aircraft is parked at Dresden airport, surrounded by ground crew and luggage carts. The scene is in black and white, depicting a rainy or overcast day with a wet runway.
A screenshot of a "table" of GitHub action runs that is implemented using div blocks and thus doesn't properly align.
Application-Module Aware Flyway Migrations As of Spring Modulith 2.0, we support the execution of module-specific Flyway migrations. Application modules are encouraged to define migrations for their own persistent data only, which means that these migrations have to be executed in the order of the module dependency tree. Assume a default Flyway setup with migrations located in classpath:db/migration, two application modules first and second (with second depending on first), and an activated spring.modulith.runtime.flyway-enabled configuration property. With that in place we will customize the Flyway setup as follows: The root migration folder will be changed to db/migration/__root. For that, the default version tracking table will be used. Additional migrations for db/migration/$moduleIdentifier will be registered with a tracking table of flyway_schema_history_$moduleIdentifier. These migrations are also set up to a baseline version of 0 and set up to baseline on migrate. Migration locations ending in a wildcard will not be customized. Note, that he version numbers used in migration scripts are now effectively scoped to the application module and should not use global ordering. By selecting which folder to place the migration files in, you can differentiate migrations always to be run from ones that will only get executed for the corresponding module. The application module test integration will only execute the default migration and the ones for modules included in the test run.
Phil Siemers performing “Schon heute“ in a living room in Dresden. Lyrics: “… ich wär gern einer deiner Freunde / Vielleicht ruf ich dich dann mal an / Was werden wir uns sagen, wenn wir eines Tages / Spüren, dass es zu Ende geht / Können wir uns dann endlich sagen, was wir uns bedeuten / Und wenn wir‘s dann verstehen, warum denn nicht schon heute?”
A screenshot of a Java exception using an internationalized exception message translating "The connection was not closed by the application and is garbage collected" to "Die Datenbank-Verbindung wurde nicht explizit geschlossen (jetzt in der Müllabfuhr)".
Application-Module-Aware Flyway Migrations As of Spring Modulith 2.0, we support the execution of module-specific Flyway migrations. Application modules are encouraged to define migrations for their own persistent data only, which means that these migrations have to be executed in the order of the module dependency tree. Assume a default Flyway setup with migrations located in classpath:db/migration, two application modules first and second (with second depending on first), and an activated spring.modulith.runtime.flyway-enabled configuration property. With that in place we will augment the configured migration to run the default one first, followed by one for classpath:db/migration/first and one for classpath:db/migration/second. By selecting which folder to place the migration files in, you can differentiate migrations always to be run from ones that will only get executed for the corresponding module. The application module test integration will only execute the default migration and the ones for modules included in the test run. We will not augment migration runs including wildcard expressions in the migration location definition.
Oliver Drotbohm standing on a stage, raising one hand while addressing an audience. In the background, a projector displays text related to evolvable systems. The speaker is wearing a black cap and glasses.
A coffee house entrance with a green awning displaying "JAVA coffee house."
A CRJ9 parked at the gate at Airport Dresden, surrounded by trucks delivering fuel and baggage.
Meet the Spring Team Come meet the Spring team! This year at Devoxx, many maintainers, advocates and contributors will be at the conference, and we’re delighted to meet with our users and members of the community. In this “open mic” session, you’ll have the opportunity to ask us anything about the various Spring projects, our current efforts and ideas for the future, and of course, the soon-to-be-released new generation with Boot 4 and Framework 7. Whether you’re a Spring veteran or a new user getting started with the project, you are more than welcome to join.
Domain-centric? Why Hexagonal and Onion Architecture are Answers to the Wrong Question To separate technical from domain code, architectural approaches like Hexagonal or Onion Architecture are currently all the rage. However, discussions about their semantic details and their mapping to the source code structure of software projects are at least equally ubiquitous. How much abstraction and mapping between architectural concepts is needed? Is persistence metadata in the domain model heresy? Above all: what is the actual goal of the exercise, and: does it have to be so complicated? We address these and other questions in a theoretical overview and by looking at concrete examples. We discuss the trade-offs of different approaches and how various tools and libraries help us to maintain the intended structural integrity.
What’s new in Spring Modulith? This talk introduces Spring Modulith, a tool for structuring maintainable Spring applications, and reviews its latest features, with a focus on the upcoming 2.0 release. Key enhancements include a new event publication registry, advanced C4 model integration, and major improvements in observability and actuator support.
Tactical Domain-Driven Design with Java and Spring This workshop explores tools and approaches for implementing tactical Domain-Driven Design (DDD) in Java, focusing on the jMolecules library for expressing DDD concepts and the Spring Modulith project for modular Spring Boot applications, including support for integration, events, testing, and documentation of rich domain models.
A chart showing the complexity of software projects (y-axis) in relation to versions released, continuously growing as development moves through the versions. A marker points to the area before the 1.0 release, stating “Most teams focus on that.” Another marker pointing at the much larger area covering four more versions, stating “…while the challenge is actually this.”
The Logical Structure view in VSCode's Spring Boot Tooling showing the Spring Modulith application modules of the RESTBucks application. The application node reveals an icon to open up a dialogue to select the stereotype groups that are supposed to be included in the project tree.
A presentation slide titled "APPLICATION STRUCTURE" discusses jQAssistant rules that validate against abstract concepts, such as Bounded Context and Technical Aspects. It illustrates relationships between concepts like "Implemented Bounded Context," "Documented Bounded Context," the former bound to jMolecules annotations and the latter described by Context Mapper.
Coke bottles in a refrigerator. The main one with a “Mate” label.
The cover of the book “Structured Design” by Edward Yourdon and Larry L. Constantine from 1979.
Screenshot of a VSCode Logical Structure project explorer that shows a Spring Modulith project's types arranged by application module, whether they're exposed to other modules or internal, followed by the assignment to concepts of Hexagonal Architecture and grouped design and technology stereotypes like DDD, Spring, Jackson, and JPA.
A refined variant of the logical structure view in VSCode displaying application structure based on architectural, design and technology stereotypes in a tree-like structure.
An image displaying a tree structure of a software application, grouping various components by their architectural stereotype, such as Domain Event Handlers, Aggregate Roots, Services, Entities.
A live music performance by Purple Disco Machine is taking place on stage, illuminated by colorful lights. In the background, a large screen displays a sunset with palm trees. The crowd is visible in front of the stage, enjoying the show.
A screenshot extract of the GitHub issues overview after a ticket has been closed showing that the actual criteria is “open tickets”, but the just-closed ticket still appears in the list.
A Behringer Wing mixing console.
Screenshot of an email inbox showing three talk proposals accepted for Devoxx Belgium.
A street sign indicating the way to the Springweg car park in Utrecht.
A map displaying Lombok district of Utrecht.
A mostly yellow, orange, red mural by street artist MadC in the city center of Wuppertal.
A four-piece drum set and a bass guitar in a church.
An animation showing emphasis on the “no” in the word “Monolith”, and “du” (phonetically “do” and personal “you” in German) in “Modulith”.
Front, back and the green vinyl record of Jeff Coffin‘s recent Only The Horizon record.
German rapper Dendemann on stage at Felsenkeller Leipzig.
A grey, slightly grim-looking Norwegian Forest cat sitting on a teal stool looking right into the camera.
Screenshot of a page of a computer programming book showing some prose text and a snippet of syntax-highlighted code.
Opening scene of Severance S1E1 in which Mark S. introduces newly severed employee Helly R. To the Macrodata Refinement division. Mark, in a business suit, sitting at a conference room table offering Helly (not in the picture) a seat.
A presentation slide quoting Russel L. Ackoff: “The quality of a system depends on how the parts fit, not how they act, taken separately.“
The title slide of a presentation called “It Takes Two to Tango – Designing Module Interactions in Modulithic Spring Applications“ depicting an outline drawing of a couple dancing.
A largely red and orange with a tint of blue mural on a wall in the the city center of Chemnitz, Germany.
The glass front entry of a store called Modulyss in Islington, London.
Newton Faulkner on stage at Islington Assembly Hall, London.
A front side view of a plane standing at the gate at Dresden Airport.