# Case study: Real-time Monitoring Engine Source: https://lean-coders.at/en/case-study-real-time-monitoring-engine > Legacy code modernized, processing time reduced by 70%: How LEAN-CODERS brought a critical monitoring engine from 32 to under 10 hours. Case Study Out with Visual Basic. In with Java. Up to 70% faster. 1. Challenges 2. Project Journey 3. Results Energy Sector 6 Months 1 Full Stack Senior Dev **~70%** Reduced Processing Time — from 32 to 10 hours **€10.000** Monthly Savings — Reduction of infrastructure costs **3 to 1** Reduced Maintenance Effort — Consolidated 3 Kubernetes Pods into 1 LEAN-CODERS optimized the **critical Core Processing Engine** of an internationally leading manufacturer of gas engines to monitor thousands of power generators worldwide. Through **architecture modernization** and **code consolidation** we were able to reduce the processing time from **32 to under 10 hours** successfully. ## Challenges The client faced critical challenges in their Reliability Engineering. Performance Bottleneck The existing Core Processing Engine for monitoring global power generator fleets took 32 hours for daily data processing – far too slow for modern demands. Legacy Architecture Outdated Visual Basic code with complex network handovers between isolated systems, hard to maintain and prone to errors. Lack of Transparency Millions of machine messages daily, but no efficient method to validate state changes and algorithms. Infrastructure Overhead Three separate Kubernetes Pods for processing, high ongoing costs. ## Project Journey Analysis & Simulation We built a comprehensive simulation environment using JavaScript (Node.js) and complete unit tests. Millions of messages could be sent through both old and new systems to precisely identify discrepancies. **This investment paid off** – we discovered that the originally desired Python solution would have been even slower than the legacy system. Architecture Redesign The client was already using Java for parts of the processing. We strategically expanded this existing Java architecture and migrated the critical processing logic from Visual Basic. **The breakthrough:** We eliminated the network handovers between systems by consolidating everything into a single, optimized Java codebase. Implementation & Validation A LEAN-CODERS Senior Developer worked closely with two experts on the client side. Each optimization was tested against real production data. **The result:** fully documented, maintainable Java code with comprehensive unit tests – readable for the entire development team. Deployment & Maintenance **Seamless rollout without downtime.** The new Core Processing Engine has been running stably in production since then and is continuously maintained and optimized by us. ## Results Long-term Partnership: The project is one of several successful projects in a multi-year collaboration. Continuous maintenance is ongoing. We deliver. They stay. Repeat. Performance 70% faster processing: From 32 hours to under 10 hours per calculation cycle Consolidated architecture: Reduced three separate Kubernetes Pods to one Costs & Maintainability ~€10,000+ monthly savings through infrastructure optimization (estimated) Dramatic reduction in helpdesk calls thanks to more precise algorithms and better reliability Fully documented in Confluence with comprehensive unit tests Technical Quality Modern Java codebase instead of hard-to-maintain Visual Basic legacy code Foundation for Follow-up Projects The new architecture has already enabled a second project for other teams in the company Team-ready Any Java developer can understand and extend the code Book a discovery call with your expert now This guy has seen it all. He knows what to do. Call him! Next Vienna Capitals website