Axoniq Conference 2025 Day 2: First-Ever Event Sourcing on Low-Code Platform (Mendix Live Demo)

🎯 Speaker:

Jakob Hützel - Software Developer, Asasis (Swiss med-tech PLM solutions)

💡 The Innovation:

First-Ever: Event sourcing with low-code platform + Axon Framework integration

The Stack:

• Mendix (low-code platform - Dutch company)

• Axon Framework & Server

• Custom integration module (2-3 days to build!)

• ByteBuddy for dynamic annotations

• JSON serialization via Mendix mappings

🔑 Integration Architecture:

• Message Payloads → Non-Persistent Entities

• Commands, Events, Queries = Mendix non-persistent entities

• No DB persistence needed (Axon handles event storage)

Message Handlers → Microflows

• Command handlers = CH_BikeAggregate_ReturnBikeCommand

• Event sourcing handlers = ESH_BikeAggregate_OnBikeReturned

• Naming convention for auto-discovery

Magic Sauce:

• Message handling adapter scans microflows at startup

• ByteBuddy dynamically creates @CommandHandler annotated classes

• Hooks into standard Axon Framework configuration

• No messy hacks required!

🎯 Real-World Project:

• Domain: Regulatory information system for medical device manufacturers

• Challenge: Help "Medical Hammer Inc." navigate laws across countries

• Team: 2 developers

• Results: 84 slices in 120 working days = 1.5 days per slice!

📊 Mendix Concepts:

• Modules: Reusable, shareable components

• Entities: Persistent, Non-persistent, View

• Microflows: Flowchart-style business logic

• Nanoflows: Front-end presentation logic

• Pages: WYSIWYG editor with auto data binding

• Studio Pro: Dark mode included! ✅

🚀 Benefits:

• ✅ Event model shines through in low-code representation

• ✅ Vertical slice encapsulation (folders per slice)

• ✅ Stable development pace as app complexity grows

• ✅ Minimal merge conflicts (one slice = one folder)

• ✅ Team scalability without coordination overhead

• ✅ Read models = Persistent entities (1:1 mapping)

• ✅ Commands/Events = Non-persistent (perfect fit!)

🎬 Live Demo Highlights:

Implemented complete "Return Bike" slice in ~30 minutes:

• Created ReturnBikeCommand entity with location & rental reference

• Configured JSON import/export mappings

• Built command handler microflow (check if bike in use)

• Built event sourcing handler (update aggregate state)

• Created UI button with nanoflow

• Extracted snippet for encapsulation

• Tested live with Axon Server running

💬 Best Quote:

"If you get your requirements right using event modeling, it doesn't matter which tech stack you choose for the remaining 20% implementation effort. Requirements, requirements, requirements!"

🏗️ Technical Details:

Serialization:

• Mendix export/import mappings (JSON)

• Wrapped in Axon Serializer interface

• Manual but straightforward

Custom Actions (Java):

• sendCommand(CommandGateway)

• applyEvent(EventStore)

• Used sparingly to keep low-code benefits

Role-Based Access:

• Entity-level RBAC built into Mendix

• Rental agent can create/modify commands