I manage Holidaysg.com and I’m looking for a expert PHP developer to step in, clear up several nagging issues, and then extend the site with a clean, well-documented API. First, the essentials: the site is already live, running on PHP, and it’s showing classic e-commerce headaches—broken links that end in 404s, a payment gateway that refuses to complete certain transactions, and an account-login flow that occasionally locks users out. On top of that, the product filters aren’t returning the right results. Once those problems are ironed out, I need new API endpoints so our mobile app and future partners can pull inventory, pricing, and booking details in real time. To make expectations crystal-clear, here’s what I need delivered: • Fix all broken links / 404 errors so every public page resolves correctly. • Repair and test the payment gateway until transactions run end-to-end without manual intervention. • Stabilise the account-login flow and ensure session handling is airtight. • Correct the product-filter logic so results match the chosen criteria every time. • Design and build RESTful API endpoints (with authentication) that expose key booking data, fully documented for future integration. Please be comfortable digging through existing PHP code, tracing bugs quickly, and writing concise, maintainable scripts. If you’ve handled similar e-commerce fixes and API builds before, I’d love to see a brief example or two alongside your proposal.