One-Versus-One AG, a Swiss sports technology company, had a critical legacy system built entirely in Qlik. The problem: 40% of the original business logic was undocumented and missing. No specs, no comments, fragmented code scattered across modules. The system was a black box that only one person had ever understood, and that person was gone.

They needed the entire platform migrated to PHP, fully functional, with zero data loss, and handed over to their internal team with complete documentation.

This wasn't a straightforward port. It was architecture recovery - reverse-engineering a system that nobody fully understood anymore.

Audited the entire Qlik codebase to map existing functionality

Identified all critical functional gaps where logic was missing or broken

Interviewed stakeholders to reconstruct business rules that existed only in people's heads

Built a complete system architecture map from scratch

Rebuilt the entire system in PHP with clean, maintainable architecture

Engineered the missing 40% of business logic from reconstructed requirements

Designed the database layer with MySQL, optimizing queries for performance

Implemented proper error handling, logging, and monitoring

Performed deep RAM optimization to reduce server resource consumption

Load tested the system under production-level traffic

Deployed using Docker containers on Linux for consistent environments

Wrote comprehensive technical documentation covering every module, every decision, every edge case

Conducted a full team handover so their developers could maintain and extend the system independently

Modular PHP architecture over monolithic rewrite: each Qlik module was migrated as an independent, testable component

MySQL query optimization: rewrote data access patterns that were causing memory bloat in the original system

Docker containerization: ensured the new system runs identically across dev, staging, and production

Git-based version control with full commit history: every reconstruction decision is traceable

Successfully migrated 100% of the legacy Qlik system to PHP

Reconstructed the missing 40% of business logic from scratch

Achieved measurable RAM optimization, reducing server resource usage

Delivered full technical documentation for seamless team handover

5-star client rating from Peter Zombori, CEO of One-Versus-One AG

Zero downtime during migration. Zero data loss.