Notes

Architecture Documentation The Core Problem Why architecture docs fail: Problem Why it happens Too much too early Spec written before code — outdated by first sprint No time during development Devs skip it under pressure, never catch up No ownership Nobody is explicitly responsible → everyone assumes someone else does it Unclear scope “What actually goes in there?” — no shared answer Solution framing: Don’t ask “how do we document everything?” — ask “what and how do we document?” Less is more. Document decisions and context, not implementation details the code already tells you. ...

ESDM – Event-Sourced Domain Modeling Website: https://www.esdm.io/ Core idea: Domain-first modeling language (YAML) that captures DDD, CQRS, and Event Sourcing building blocks in a machine- and human-readable format. The Core Message Talk about domain first — technology is secondary. Common mistake: teams jump to “we’ll use Kafka / PostgreSQL / microservices” before defining what the system actually does. ESDM flips this: Describe what happens in the domain (events, commands, rules) Model who triggers what and what results are needed Only then decide on tech stack This makes conversations with domain experts productive — they don’t need to understand Kafka to participate. ...

Observability: Does My App Work? Core Principle Balance: Not too much, not too little. Every metric and log must answer a real operational question. Monitoring The Right Amount Use Icinga (as already deployed in your infrastructure) and focus on: Where can we take action if something breaks? Where is the signal-to-noise ratio actually worth it? Question every metric: If this threshold fires, can we do something about it in 30 seconds? If not, it’s noise. ...

Spring, DDD & Architecture Workshop Notes Spring Security: Upcoming Fixes (May 18) Rollout date: 18. Mai Spring releases a batch of security fixes discovered via the Mythos vulnerability check. All branches up to Spring 2.7 are affected. Blog post with full details drops next week If you run anything ≤ 2.7, plan the upgrade now Full talk at DevOps Antwerpen covers this in depth Domain-Driven Design (DDD) Extensional vs. Intensional Term Meaning Examples Extensional Represents external reality — maps things from outside the domain DTOs, API models, database rows Intensional Expresses domain concepts from within — gives things meaning Value Objects, Entities, Aggregates The goal: code that reads like the domain language, not like database schema. ...