Architecture that scales
Hexagonal boundaries, microservices and Kafka event streams, set up so the next requirement fits in without a rewrite.
I build software for insurers, railways and industry. It handles the load, and releases go out without drama.
PatrickBatke
Role
Lead Fullstack Developercertified Software Architect (iSAQB)
Base
Vienna, AT11+ years in production
Engagement
Freelance · Patrick Batke e.U.Remote from Vienna · on-site in Vienna 1–2 days/week
Fullstack & Architecture · Vienna, ATJava · Spring Boot · Kafka · AWS · AngularAbout
Eleven years across five industries
Most of my work is the part that has to keep running after the demo: a claims platform for one of the world's largest insurers, passenger information for Vienna's newest subway trains, and data platforms that handle a million records.
I started as a fullstack developer and moved into architecture. I'm iSAQB certified, and I've used hexagonal boundaries, event streams and automated regression tests on real systems. There they decide whether a release goes smoothly or turns into a weekend of firefighting. I prefer the smooth kind.
I'm based in Vienna and work in German or English, from the first architecture sketch to the production dashboard.
Releases on schedule
Automated regression tests and a clean release cycle. On my current project, that saves a week per sprint.
Backend to frontend
Spring Boot and Kotlin on the backend, React, Angular or Vue 3 on the frontend, deployed to GCP or AWS. You work with one person, so nothing gets lost between teams.
What I don't do
- I won't ship a prototype and call it a product.
- I don't add tools a system doesn't need.
- I'm still around after the handover.
Experience
Where I've worked
Lead Fullstack Developer & Software Architect
2024 – nowGlobal Insurance Enterprise · Vienna
- Claims platform for multi-country rollout: customization effort per market down 40%
- Hexagonal microservices: onboarding time down 25%, boundary defects down 30%
- Kafka event processing at 10,000+ messages per second with 99.9% delivery
- Automated regression tests: production incidents down 35%, one week saved per sprint
Senior Fullstack Developer
2022 – 2024Siemens · Vienna
- PI+ passenger information for Vienna's next-generation subway: deployed fleet-wide, uptime up 25%
- Wiener Linien real-time API integration: update latency down 30%
- Media delivery and live streams to the passenger displays on the trains
- Test automation: bug-related incidents down at least 50%
Fullstack Developer
2021 – 2022Freelance · CAESAR · Remote
- Insurance broker platform: portfolio admin time down 30%
- OMDS 3.0 XML integration: 1M+ data records processed
- Portfolio growth monitoring over configurable periods
Fullstack Developer
2019 – 2021Hexagon AB · Vienna
- M.App Enterprise GIS platform: 10+ releases shipped, bug issues down 40%
- Led development of the styling editor for geographic data (OpenGIS, live map preview)
- GIS analyst productivity up 25%
Fullstack Developer
2018 – 2019Neuherz & Partner · Vienna
- Packaging design workflow app: approval time from 5 days to 3
- Party pretzel configurator for a supermarket chain: 90% customer satisfaction
2016 · HTL Donaustadt, Software Engineering · 2023 · iSAQB Certified Professional for Software Architecture
Featured01 / 04
Projects I shipped
Insurance Claims Platform
Client DeliveryLead Fullstack Developer & Software Architect
Event-driven claims processing, built as hexagonal microservices.
Global Insurance Enterprise · 2024 – now
Context
The old monolith couldn't keep up with the claim volume, and every new country needed 40% extra customization work.
Approach
Kafka event processing at over 10,000 messages per second, hexagonal microservices, and automated regression tests that cover all services.
Result
−40% rollout effort · −35% incidents · +60% test coverage
Spring Boot · Kafka · MongoDB · Angular · Microservices
PI+ Passenger Information
Deployed Fleet-WideSenior Fullstack Developer
Live passenger information for Vienna's newest subway trains.
Siemens · Wiener Linien · 2022 – 2024
Context
Passengers needed live updates across the whole network, and they had to be fast and reliable.
Approach
Connected the real-time transit APIs, delivered media to the train displays, and automated the tests.
Result
Deployed fleet-wide · +25% uptime · −30% data latency
Java · Spring Boot · TypeScript · Angular
Broker Platform CAESAR
In ProductionFullstack Developer
A platform for insurance brokers that imports OMDS 3.0 data.
CAESAR · Freelance · 2021 – 2022
Context
Brokers lost 30% of their time to manual portfolio data processing.
Approach
Policy, claims and commission views with sorting and filtering, automatic OMDS 3.0 XML import, and portfolio growth tracking.
Result
1M+ records processed · −30% portfolio admin time
React · Spring Boot · XML · OMDS 3.0
M.App Enterprise
Fullstack Developer
Worked on the GIS platform through 10+ releases.
Hexagon · 2019 – 2021
−40% bug issues
C#/.NET · Java · Angular · Vue 3
Geo Styling Editor
Lead Developer
An OpenGIS styling editor with a live map preview.
Hexagon · 2019 – 2021
+25% analyst productivity
Vue 3 · OpenGIS
Packaging Workflow
Lead Developer
Approval workflow for packaging designs, with feedback inside the app.
Neuherz & Partner · 2018 – 2019
Approvals 5d → 3d
C#/.NET · Angular · MS SQL
Party Pretzel Configurator
Fullstack Developer
Party pretzel configurator for a supermarket chain's customers.
Neuherz & Partner · 2018 – 2019
90% customer satisfaction
C#/.NET · Angular
Stack
What I work with
I've used everything here in systems that went live.
Languages
- Java
- Kotlin
- Go
- C#
- TypeScript
- JavaScript
- Python
Frameworks
- Spring Boot
- .NET
- React
- Angular
- Vue 3
- Next.js
Cloud & DevOps
- GCP
- AWS
- Azure
- Kubernetes
- Docker
- Terraform
- GitHub Actions
- Jenkins
Data & Messaging
- PostgreSQL
- MongoDB
- Kafka
- MS SQL
- Oracle
- XML
Architecture
- Microservices
- Hexagonal
- Event-driven
- MVC
Contact
Tell me about your project
Describe the system you need, or the one that's causing you trouble. I'll get back to you within 24 hours.
- Availability
- 40 hours a week. Ask me about current availability.
- Rate
- All-in hourly rate. Ask me for a quote.
- Roles
- Lead Developer · Software Architect · Tech Lead
- Domains
- Finance · Insurance · Transportation