Across government deployments in Japan, a consistent pattern has emerged: agencies have spatial data and clear public interest use cases, but lack the technical staff to build and operate a GIS platform. Because Re:Earth is a SaaS product, the answer is not to teach them how to deploy software — it is to let them start building immediately. A no-code visual editor and a plugin-based customization model mean that non-technical government staff can go from data to a published platform without writing code, managing infrastructure, or waiting on an IT department.

This talk presents two categories of real deployments:

Public-facing GIS — from Japan's national 3D urban model initiative covering 100+ municipalities, to open data portals built by local governments to make spatial datasets publicly accessible. In each case, non-technical staff independently manage data publication through Re:Earth CMS, with no backend to operate.

Participatory GIS — citizen urban planning workshops and disaster prevention simulation exercises, where residents and local emergency officers engage with spatial scenarios directly in the browser. No installation, no prior GIS experience required.

The focus is on lessons learned: where the no-code model reaches its limits, what "light customization via plugins" actually means in practice, and what open-source licensing concretely changes for government procurement decisions. We will also share how plugins developed for one agency have been reused across others — an open-source multiplier effect that proprietary tools cannot replicate.