Backend Developer Needed — Custom HTML Tools + Integrations (Ongoing, Ad-Hoc)

OVERVIEW We're an Australian no-code software implementation company. We've built some custom lead-gen and client-facing tools in HTML/JS, and need a developer to build the backend layer connecting them properly to our other systems. This project has three components, priced as one fixed-fee engagement: 1. Core backend system - built once, and built for scalability, not as a one-off script. This is the reusable foundation (database, intake endpoint, private scoring pattern, unique per-person results URLs, ConvertKit integration, results-by-email) that future tools will plug into, not something rebuilt each time. 2. Build and test Lead Magnet Quiz 1 - a scored self-assessment quiz (multiple-choice questions across several categories, producing a visual results report). We'll provide the finished HTML/JS file as-is. High-level flow: a visitor enters their name and email, answers the quiz questions, and sees their results report instantly on-screen; a unique URL to their own results also gets emailed to them; their email is connected into ConvertKit; and their full responses/results are made available back to us in a suitable format (e.g. stored in a database we can access, or another agreed method). 3. Build and test Lead Magnet Quiz 2 - a second quiz following the same end-to-end flow described above, reusing everything built in component 1 - expect meaningfully less effort than Quiz 1 since the system already exists. HOW WE EXPECT THIS APPROACHED -Built on our existing web hosting (cPanel, supports PHP/MySQL) - this is integration work against well-documented APIs (ConvertKit, Jotform), not new application development. - Security-first by default: credentials scoped and never exposed client-side, private logic genuinely server-side, safe database practices - This is backend/integration work only - the existing front-end tools' design and logic won't need to change, and the finished HTML/JS files will be provided as-is Separately, and not part of this specific project's scope - we also have a second use case: pushing our own data (from ClickUp or Google Sheets) to a live, branded HTML front end, that we expect to bring to whoever we hire here as future ad-hoc work once this project is done. We'd expect the right person for this role to already be familiar with building that kind of thing, even though it's not part of this initial engagement. SKILLS NEEDED - PHP and MySQL, comfortable outside a WordPress plugin context - Genuine REST API integration experience (auth, JSON, webhooks) - cPanel/shared-hosting environment comfort - Security-conscious without being told WHAT WE'RE LOOKING FOR An experienced developer available for ongoing, ad-hoc project work - able to pick up a scoped brief and work autonomously with minimal oversight, not a large agency or a single one-off engagement. This particular project is small, not a large build - but it's the first of an ongoing relationship, and future projects will vary in size from quick, small tasks to larger builds. Happy to share a detailed technical brief with shortlisted candidates.