Build Deterministic Real Estate Mapping App (Google Sheets → Map Sync)

Summary We are building an internal system called AgentMap. It assigns Australian suburbs to subscribed real estate agents and shows their coverage on a map. We already built an MVP using Lovable and Base44. It works, but it has duplicate records, unreliable syncing, and structural issues. We now want to rebuild this properly with a reliable sync, and correct database structure. This is mainly a backend and data architecture job, with a simple frontend and map. What the app needs to do: Sync agent suburb data from Google Sheets Assign exactly one agent to each suburb Prevent duplicates completely Update when the sheet changes (can be automated or manual sync) Remove records when they are deleted from the sheet Display suburb boundaries on a map using a GeoJSON file we already have Colour suburbs differently based on subscription type Ability to search address/suburb/postcode and map zoom/drops pin on location We already have: MVP Google Sheet with real data Full GeoJSON suburb boundary file Clear logic and structure We need it rebuilt properly so it is reliable and scalable - currently have 1000 rows of data but needs to be able to scale to around 12,000 Features to build Backend: Reliable Google Sheets sync Safe handling of updates, deletes, and retries Prevent duplicate suburbs and assignments Link suburbs to geometry from GeoJSON Frontend: Map showing suburb coverage - with each suburb having agents name on it Button to trigger sync and see status Suggested tech stack: Open to your recommendation Important experience You must have experience with: Building full stack web apps Database schema design Google Sheets API Preventing duplicate data Map integrations (GeoJSON, Mapbox, Leaflet, etc) Bonus if you have built sync systems before. Deliverables Internally used system only - priority on this is high to get up and running ASAP but speed of sync etc is not important as it is not customer facing Reliable Google Sheets sync Working suburb map Deployed and ready to use Timeline: Need completed ASAP When applying, please include Examples of similar apps you built Your recommended stack Your experience with Google Sheets integration Your experience with maps and GeoJSON

Project ID: 40245447