I have a site on OsCommerce which was previously V2 but now changed to V4 code-base and now need a single specialist who truly understands the quirks of each version and, more importantly, how they interact when data and design elements need to cross over. Right now the entire cart system is broken so I need someone to fix it. If you have demonstrable experience working in both versions—especially if you’ve bridged data, theming, or custom modules between them—let’s talk. Please reference a project or two where you solved a similar version-mix challenge and outline the tech stack you used (PHP version, database, any middleware). I will make decisions quickly once I see evidence of that dual-version expertise.