The recording of my Spring I/O 2026 talk is now online 🎥 Spec-driven Development: How AI Changed Everything (And Nothing) AI is changing how we build software. But one thing has not changed: unclear requirements still lead to unclear software. In this talk, I show why specs become even more important when we use AI coding agents. The better we describe the intended behavior, the better AI can help us implement, test, and evolve the system. I also explain how the AI Unified Process uses: - Requirements Catalog - Entity Model - System Use Cases - Traceability from specs to code and tests The goal is not to replace developers. The goal is to give AI the right context, so developers can focus more on design, review, and domain correctness. Recording: youtube.com/watch?v=35dH6q18… Thanks to Spring I/O for publishing the recording. #SpringIO #AI #SoftwareDevelopment #SpecDrivenDevelopment #Java #SpringBoot #Architecture #AIUnifiedProcess

The recording from my talk at @JavaOne is online 😀 Do You Really Need Hibernate? youtu.be/Vd0BNA6m3Kw?is=Rfdr…

☕🇩🇪 Java developers in Berlin, don't miss this! Join the Java User Group Berlin Brandenburg on June 9 for a session with Oracle ACE Pro and Java Champion Simon Martinelli, who will explore how Spec-Driven Development and AI are changing software development. 🤖☕ 📅 June 9, 2026 | 🎤 @simas_ch 🔗 social.ora.cl/6014B8SN9I #OracleACE

"Just do it" should be the motto of AI-driven development. Too many people build theories and polish concepts that never touch a real project. With AI moving this fast, those concepts are outdated before they ever ship. But raw "just do it" is also a trap. If you only act and never reflect, you build the same broken workflow ten times without noticing. The real shift is speed and grounding. Do not spend six months on a concept and then test it. Build it, see what breaks, adjust. Theory should come from practice, not before it. One thing that helps: know your half-lives. Tool level knowledge (which prompt, which model, which CLI flag) is dead in weeks. The principles you abstract from real work last much longer. Keep the spec tight. Take brownfield context seriously. Always review the output. Do not confuse the two, or you will be holding something dead in six months. Think less at the whiteboard. Think closer to the code. #AIUP #SpecDrivenDevelopment

Spec-driven Development ist für mich der Weg, wie KI-gestützte Entwicklung im Enterprise-Umfeld wirklich funktioniert. An den Workshop-Tagen 2026 zeige ich, wie das geht. In meinem ganztägigen Workshop "Spec-driven Development mit dem AI Unified Process" führe ich dich durch den gesamten Prozess: von der Vision über den Anforderungskatalog bis zur lauffähigen Software. Wir arbeiten mit Claude Code, Skills und MCP für Vaadin, jOOQ, Karibu Testing und Playwright. 📅 8. September 2026, ganztägig 📍 Raum F91 Wenn du verstehen willst, wie klare Spezifikationen und KI zusammenspielen, bist du hier richtig. #AIUP #SpecDrivenDevelopment #Java #Vaadin #SpringBoot #jOOQ

Built by multiple stories. #springofficehours #SimonMartinelli watch more at youtube.com/live/BZjQo0OJD_A…

Mit my kSuite erhältst du gratis: ✅ eine verschlüsselte E-Mail-Adresse, ✅ 15 GB Cloud, ✅ Videokonferenzen, ✅ Dateiübertragung bis zu 50 GB, alles gehostet im Herzen Europas, in Rechenzentren, die mit erneuerbaren Energien betrieben werden. Und vor allem: Deine Daten bleiben deine. Übernimm wieder die Kontrolle 👉 infomaniak.com/gtl/ksuite.my…

I had a great time at Spring Office Hours! We talked about Spec-Driven Development. Thank you @therealdanvega for having me! Watch the short clip here: youtube.com/shorts/ns8C_F6dF… And the full session is here: youtube.com/live/BZjQo0OJD_A #SpringBoot #SpecDrivenDevelopment #springofficehours

P.S.: There wasn't any obvious problem, since no exception was thrown. The issue was a chain of multiple raise conditions! (Which I would not have found so fast)

I recently had an issue reported on a production system. I let Claude analyse it. It almost immediately pointed at the right spot and explained how the situation can be explained and fixed. Without Claude, I probably would have spent hours and hours!

Let's be honest: AI finds more bugs in code than humans. I just checked a pull request with Qodo. It detected a bug and suggested a fix. Using that suggestion, Claude Code then discovered another, similar bug. I would never have noticed those bugs.

I've building software professionally for more than 25 years but I can safely say NOTHING compares to the exhilaration of building software with AI and watching it unfold in front of my eyes way better than anything I could ever build myself

I hate dark mode! Please add an option to switch the theme when creating a website for your product or an app! Thank you 🙏

Unpopular opinion: Many think token costs are high, but they don't consider that labor costs money, too.

Most developers think scaling up means running more agents in parallel. But data from 250,000 real engineers shows there's a hard ceiling: even the most experienced developers max out at around 4 concurrent agents — and at that point, 80% of attention collapses onto just one. Nick Arcolano from Jellyfish explains why human attention is the actual bottleneck, and what it would take to truly break through. Watch the full episode at youtu.be/GbHfzFcIa0o or listen wherever you get your podcasts. #AI #agenticcoding #claudecode #codex #AIskills

One of the more interesting shifts in software engineering right now is the move from AI prototypes to production systems. This workshop explores what that looks like for Java teams. Led by Susanne Pieterse, Contributor to LangChain4J, iSAQB Software Architect, and international speaker, the session covers practical topics such as agent design, evaluation, guardrails, observability, and production readiness. Sandra Ahlgrimm, Senior AI and Java Advocate at Microsoft, will also be joining for the panel discussion. If you're interested in how AI is being integrated into real-world Java applications, this looks like a valuable session - eventbrite.co.uk/e/building-… Use code JAVA50 to get 50% off your ticket.

The recording of my second GIDS 2026 talk is now online. "Spec-Driven Development: How AI Changes Everything (And Nothing)" This is a new way to build software. You write your requirements once. Then AI generates the rest: diagrams, models, and code. When the requirements change, everything updates with them. No more outdated docs. In this talk I start from a real system use case and build a full-stack Java application live with AI. You will see how to write requirements that AI understands, and how to keep everything connected from the business need down to working code. This is not about replacing developers. It is about letting AI handle the boring parts, so we can focus on what really matters: understanding what the business needs. Watch it here: youtu.be/82lCQdG6CsU #Java #SpringBoot #Vaadin #jOOQ #AI #SpecDrivenDevelopment #GIDS2026

The recording of my GIDS 2026 talk is now online. "Goodbye Microservices, Hello Self-Contained Systems" Microservices promised scalability and agility. But for many teams they brought the opposite: more complexity, hard debugging, and too many small services to maintain. In this talk I show an alternative. Self-Contained Systems (SCS) give you clear boundaries and independent teams, without the operational pain of microservices. I share a real project: a 20-year-old ERP monolith that we modernise step by step. Each system has its own Vaadin UI, Spring Boot backend, and database schema. No big rewrite. No distributed big ball of mud. If you are stuck in the monolith vs. microservices debate, there is a smarter path. Watch it here: youtu.be/hW22FxcrtkA #Java #SpringBoot #Vaadin #SoftwareArchitecture #Microservices #GIDS2026

Fully agree. Some things become clear only when you try them. Start small, learn fast, keep it simple. 👇

Simon, I don't know where to begin on how right you are. I have achieved so much more by 'doing' than by discussing. As have the teams I have worked with who work this way.