Active Group‘s developer conference BOB 2026 on April 13 was the biggest yet. Here is a short retrospective. As always, we‘ve linked recordings of our talks.

This hopefully also serves as an appetizer for the next BOB on February 26, 2027, in Berlin, as usual. The Call for that is open as of today and runs until November 2. Send us your ideas for what‘s best in software development!

Traditionally, BOB is full of talks and tutorials on exciting technologies and techniques. We had been particularly looking forward to our Keynote on Digital Sovereignty, as Stefan Kaufmann looks for finding societal good through IT and digital transformation. In the „age of AI“, this has gone a bit out of fashion, which makes it all the more relevant for BOB (and for all of us).

We had put a category for AI-related topics in the BOB Call, but in the end, no AI talk made it in the program. Still (or maybe therefore?), we had great fun with 16 talks and 8 tutorials: There‘s no shortage of topics beyond AI.

This BOB developed a particular focus on the OCaml programming language, that has been on the up for many years. OCaml can play to its strength particularly in large projects. Its module system - the most powerful amongst practical languages - supports architectural work enormously: Xavier Woestyne gave as an overview. Paul-Elliott‘s talk about implementing undo FUnctionality was a particular delight for the audience. Moreover, Nicolas Osborne showed us how to do specifications in OCaml, and how they develop into tests. Finally, Hannes Mehnert showed how to achieve great things with the OCaml-based Mirage unikernel OS.

In Scala, implementing effects using capabilities is hot right now: Nicolas Rinaudo helped us understand them.

Even outside originally functional languages, functional programming is making inroads. Our colleage Till Rauch together with Falk Sippach talked about how to implement concepts from Haskell in Java.

For a long time, Swift has been the language of choice for Apple projects, and it‘s even better when used functionally. Manuel Chakravarty continued his talk series on the subject and talked about UI development with SwiftUI. Franz Thoma talked about the pragmatics of developing UI components with Storybook.

Software architecture with Linked Data was the subject of the talk of our colleague Markus Schlegel, who reported from one of our projects.

Formal methods is one of the subjects dear to ourt heart, so we were particularly happy about the many submissions in this category. Currently, Lean is the hot tool, and Julia Himmel gave us a look into the engine room. Olaf Klinke showed us how to take formal methods into the practice of digital transformation. Philipp Kant taught us about zero-knowledge proofs that help us prove information about us without giving away too much.

And there were more talks on practical development: Ariadne Engelbrecht gave easy-to implement tips on accessibility. Alex Thiemann reported on API design at Stripe and Martin Grotzke about Reactive Programming in practice.

For many hearts, we‘d hoped that our friend Fritz Henglein would finally come to BOB. Finally, 2026 was the year, and he showed in his talk how to break through seemingly impenetrable performance barriers of database queries. Finally, Lutz Hühnken found a few programming languages that are exotic even by BOB‘s standards: Flix, Unison, Strand, and Verse.

Tutorials

As usual, BOB had great tutorials: Joachim Breitner on Lean, Beat Hagenlocher TypeScript, Théo Tyburn on functional 3D graphics, Carine Morel and Sudha Parimala on Multicore OCaml, Andres Löh Haskell, Holger Tiemeyer on Mutiny und Quarkus, Michael Koppmann on illegal states (and how to avoid them), and Irmhild Rogalla and Alex Ackermann on accessibility.

At this poin we‘d like to thank our sponsors entwickler.de-Akademie, the iSAQB, TNG Technology Consulting, and WellTyped for their generous support.

As we were sold out today, we‘ve booked larger rooms for the next BOB (again at the Scandic at Potsdamer Platz), and are looking forward to even more of you in 2027!