Create a Platform, then add the Systems that actually run on it. Reuse an existing System across multiple Platforms if it's wired up more than one way (e.g. Salesforce reachable via both AWS and Point-to-Point). Click a Platform or System to track its own setup checklist and target date.
Every Integration that runs on each Platform, across every Integration Epic — the "how much runs through X" view.
Every Integration that touches each System, as either its source or its target, across every Integration Epic.
Read-only rollup of every integration epic and integration, regardless of what's shown elsewhere. Color reflects the decision date: green once the checklist is fully signed off, red once the decide-by date has passed with work still open, neutral otherwise.