Full-Stack WebGIS Application Development

I need a complete WebGIS platform that lets our team upload and explore spatial data connected to our outdoor-banner projects. The core idea is simple: drag-and-drop any of our GeoTIFF or orthomosaic images, vector files such as Shapefile, GeoJSON, or KML, even plain spreadsheets with latitude-longitude columns, and see them instantly appear on an interactive map. Once the data is in, the map must feel fluid. Colleagues should be able to zoom, pan, and toggle individual layers on or off without page reloads, adjust layer opacity, and switch basemaps if needed. A built-in ruler tool has to measure both distance and area accurately, while a drawing palette lets us sketch new points, lines, or polygons, refine their vertices, and save everything back to the database with attributes intact. I am flexible about the tech stack as long as it is open source and container-friendly—Leaflet, Mapbox GL JS, or OpenLayers on the front end; Node/Express, Python/FastAPI, or Java/Spring backed by PostGIS and a map server such as GeoServer or MapServer on the back end are all fine. The finished app should run through Docker Compose so any teammate can spin it up with one command. Deliverables • Source code in a private Git repository • Docker-based deployment scripts (or Compose file) • README with clear setup and usage notes • A short demo—or live link—showing layer toggling, measuring, and draw/edit/save in action Acceptance criteria: I can deploy locally, upload sample raster, vector, and spreadsheet data, turn layers on/off, measure, and draw features without errors or visible lag. Please outline the stack you prefer and an estimated timeline for an MVP when you reply.