Well the bare minimum that you have to tell your customers is your cloud provider / hosting provider, then you sometimes have a separate provider for Object Sto

Well the bare minimum that you have to tell your customers is your cloud provider / hosting provider, then you sometimes have a separate provider for Object Storage (S3 or Backblaze), maybe another one for email delivery (Mailgun). You might have an invoicing/CRM portal (Stripe), SCM (Github), Chat (Slack), your own email setup (Gmail). And that is not even talking about any client-side tracking, things like Google Analytics etc. So it really makes sense to cut down the number of third parties, especially if there is any scenario in which they would be handling PII, and especially if you're selling to customers in heavily regulated industries.