I started my career working for digital and advertising agencies. We always prepared valuable UX deliverables like user journeys or service blueprints that were primarily used as a prop for client presentations but were forgotten right after.
After moving in-house, I realized that overdesigned PDFs were not the right format for documenting new learnings or future plans. I started to view these documents as a live dataset instead of a design deliverable. After a few trials and errors, we found out that airtable is a flexible tool to host this information for its organization capabilities like row grouping and inter-table links. Now we use our customer journey airtable as the primary resource for evaluating new initiatives and documenting back-stage processes and learnings.
While the content and the structure of this document is highly dependant on the business that it's leveraged for, our current template could be used as a good starting point if you want to build one for your product.
I took out all our proprietary information from the document (leaving a few records as examples) and created a read-only view of the document. You can duplicate the base and build your own.