Web Developer for Open, Customizable Browser-Based Horse Community Game (Backend/Platform)

The project: I'm building a browser-based virtual horse community in the classic style of early Horseland / Horse Phenomena - an open, text-based game built around player customization, not a stat-driven simulation. Players create horses with freely chosen details (name, breed, color, height, description), set their own pictures and avatars, and style their own profile pages with custom HTML/CSS. There is no color/trait genetics and no computed stats. The only automated logic in the game is a simple, deterministic breed-inheritance rule (described below) that governs breed alone and nothing else. I handle the design, front-end styling, and the custom-layout system myself. I'm hiring for the backend and platform plumbing that makes the open, user-generated side work safely. --- What you'd build (MVP scope): - Accounts & profiles: registration, login, password reset, roles (player/mod/admin), public profiles. - Custom layouts: players apply their own HTML/CSS to profile (and optionally horse) pages, safely sanitized/sandboxed. This is the headline feature and the core technical challenge. - Horse records: "foundation" horses (bought from in-game store with in-game currency) with fully open, user-typed fields (breed, color, height, description) plus a controlled sex (Stallion/Mare/Gelding). Breed uses autocomplete against a growing vocabulary, creating new breeds on the fly. - Breeding & breed inheritance: breeding a Stallion × Mare produces a foal whose breed is derived by a simple set-union rule (same breed → that breed; different → a cross), including recognized cross names from a staff-curated dictionary (e.g. Arabian × Quarter Horse → "Quarab"). Everything else about the foal stays player-chosen. Geldings can't breed. No percentages, no stats, no color genetics. - Images: a picture per horse and an avatar per player, with moderation hooks (upload-vs-embed model TBD together). - Community: private messaging, a chatroom, a basic forum, and content reporting. - Light economy: a single in-game currency on a transactions ledger. - Shows/events: players enter horses; placings assigned by simple/random or judged logic (never stat-computed). - Moderation & admin: dashboard for reports and user actions, plus a small UI to maintain the recognized-crosses dictionary. I have a full written spec (feature list + data model) I'll share with serious candidates. Key challenge (please address in your application): The core technical problem is safely allowing user-generated HTML/CSS and images (sanitization, XSS prevention, scoped/sandboxed rendering, content moderation, and image handling) while keeping the experience open and unrestrictive. Tell me how you'd approach letting players inject custom layouts without creating security holes, and how you'd handle player images (hosted uploads vs. embedded URLs, and the tradeoffs). --- Nice to have: - You've played or built games in this genre (Horseland, HP, Howrse, or similar) and understand why openness matters here (a dev who "helpfully" adds enforced stats or locked-down fields would be building the wrong game.) - Comfort with a modern web stack (e.g. Next.js + Postgres, or your well-justified alternative). - Awareness of moderation and youth-audience considerations (this genre skews young; COPPA-style data handling matters). --- Practical terms: Scope: MVP only for this engagement. Ongoing maintenance is a separate arrangement we can discuss. Ownership: All code and assets delivered as work-made-for-hire, fully owned by me, with a signed agreement to that effect. Please include: relevant work samples (live sites/games preferred), your proposed stack with a one-line reason, a rough estimate/rate, and your answer to the "Key challenge" above. --- To apply: Send links to things you've built, your take on the custom-HTML/image challenge, and your availability. Serious candidates get the full MVP feature list and data model.