Workshop
One to two days, hands-on. "Proxies in Java — from JDK dynamic proxies to annotation processing." Designed for a focused engineering team.
From €2,500 per day · team rate
Workshop details →★ Made in EU · EU-based consultancy
Need this built for your stack?
Custom annotation processors, proxy architectures and Java-26 migrations — from the author of ProxyBuilder.
Three ways we work together
Pick the format that fits the engagement. All three can run remote, on-site or hybrid.
Architecture review
Independent assessment of an existing AOP or proxy setup, with a migration path to generated code, GraalVM and JPMS where it makes sense.
From €1,800 per day · 3–5 day engagement
Review details →Custom processor engineering
Build custom annotation processors on top of ProxyBuilder — security wrappers, audit-trail emission, multi-tenancy guards — tailored to your domain.
Fixed-price scoping · weekly retainer available
Engineering details →Why work with Sven Ruppert
Java architect with over twenty years of experience, maintainer of ProxyBuilder since 2013, former Developer Advocate at JFrog and Vaadin. Oracle Developer Champion, JCP Member, DevOps Institute Ambassador.
Regular speaker at JavaOne, Devoxx and JCON; author of several articles and a book chapter on annotation processing and JDK internals. Working as an independent consultant from the EU since 2024.
Selected engagements
Anonymised highlights from recent work. Detailed references on request, under NDA.
Spring AOP → generated proxies
Migration of cross-cutting concerns from Spring AOP to annotation-generated proxies. Startup time reduced by 40 %, GraalVM native-image-ready. Three-day engagement.
Custom security processor
Bespoke annotation processor emitting audit-trail entries. Compliance requirements derived directly from annotation metadata, no runtime reflection on the audit path.
Multi-tenant proxy guards
Designed and implemented tenant-isolation proxies for service-layer interfaces. Compile-time checks for missing tenant scoping on new code.
JPMS migration workshop
Two-day workshop and follow-up review covering module-info design, jdeps validation and migration patterns for a 1 MLOC legacy codebase.
Frequently asked
Which languages are supported?
English and German. On-site engagements default to the local language; written deliverables default to English unless requested otherwise.
Remote or on-site?
Both. Most workshops and reviews run remote over video; on-site is straightforward across the EU and DACH region. Travel is billed separately.
Can we sign an NDA?
Yes. A mutual NDA before the intro call is fine; for engagements with regulated data, we will agree on a custom NDA that fits your compliance requirements.
How does invoicing work?
EU-compliant invoices via a German-registered freelance practice. Payment terms 14 days net. Multi-day engagements may be split into a kick-off and a delivery invoice on request.
How quickly can an engagement start?
Typical lead time is two to four weeks. Short reviews can sometimes start within a week if calendars align.
Ready to talk?
First 30-minute call, no commitment. We see if the engagement fits and how to scope it.