Modernize without meltdown

Start with assessment: Use OutSystems' conversion assessment tool to review your apps, map architecture (e.g., modules to libraries/applications), and estimate effort. Prepare by making O11 apps ODC-compatible (fix patterns, use Domain-Driven Architecture, update SQL for Aurora PostgreSQL). Convert code with tools or partners, it often needs manual tweaks for logic, integrations, and flows. Migrate data via export/import or coexistence/sync for minimal disruption. Test thoroughly in ODC, then cut over gradually. It's not automatic; plan for weeks to months depending on complexity, but tools and partners speed it up.

Yes, but it's not easy or quick. OutSystems generates standard .NET code (C#, HTML, JS, CSS) that you can export and detach from the platform. You can run apps as regular .NET apps without OutSystems runtime. Data exports cleanly from the database. However, business logic, UI, and integrations are tied to OutSystems models, so full migration often means rebuilding parts manually, it's costly and time-consuming. Many teams rebuild instead of migrating directly due to effort. True "no lock-in" exists technically, but practically, it's better to avoid deep customizations early.

Plan phased: Use balanced/rolling upgrades where front-ends upgrade one by one while others handle traffic. Test everything in staging first, check breaking changes, side effects, and custom code. For migrations (e.g., to ODC or new env), run dual setups with data sync or API bridging during transition. Schedule during low-usage windows, have rollback plans (backups, snapshots), and monitor closely. For critical apps, prioritize coexistence or blue-green approaches. Zero downtime is achievable with good prep, but always expect some risk, communicate with business stakeholders.

First, clone/restore your current database to the new DB server and clean old/unneeded data. Install fresh OutSystems (target version) on the new server, then point the configuration tool to the restored DB. Republish all apps/modules to the new environment and fix any issues (e.g., extensions, connections). Test fully before switching traffic. For production, use a cutover window or load balancer to redirect gradually. This approach reduces risk compared to in-place, easier rollback via old setup. Always back up everything first.

Prefer migrating to a new environment: Set up fresh servers/DB for OS11, migrate/clone the database, install OS11, republish apps, and switch over. It's safer with easier rollback (just revert to old infra), less risk of corrupting live systems, and lets you prepare/test ahead. In-place upgrade works for simpler setups but risks downtime or issues during the process. New env is recommended for production/high-availability, many teams choose it for cleaner upgrades. Check official docs for side effects/breaking changes in both cases.