The person logging in is not always the customer.
Login proves who is at the screen. It does not prove what they own, may manage, or can buy. Model those questions separately before the edge cases arrive.
Multi-market apps: the central vs. local paradox
How to run a multi-market app with one shared codebase, local deployments, clear decision rights, and room for real market differences.
The app consolidation playbook
Large app portfolios grow through local decisions, acquisitions, and separate teams. Consolidation works when one owner can remove duplication while keeping the local differences customers need.
Build the API layer before replacing the billing system.
Do not make digital delivery wait for a full OSS/BSS transformation. Put a stable API contract between new demand and the legacy systems already running.