Your question is how to bring this up with your client? I'd either call a meeting or send an e-mail depending on the sort of communication culture and draw the

Your question is how to bring this up with your client? I'd either call a meeting or send an e-mail depending on the sort of communication culture and draw their attention to what would seem to be a risk to their business. But just pointing out the problem doesn't help unless you have a plan. I would deal with this by calling up the founder directly to explain my concerns, after discussing it with the client. I would ask the founder of the SaaS for: 1. A copy of the software to be deployed into a GCP account I control 2. A source code escrow agreement - if certain conditions are reached (bankruptcy/founder's death) then you gain the source code and a license to it. Of course, I would expect to pay a lot for this but it's worth it as apparently this is a mission-critical piece of software. You could frame this as an "enterprise" deal. Tell them what you want and ask them to go away and give you a price. I'd expect that the price to be cheaper than developing it and porting it yourself. But then, thinking outside the box, you could bring up another idea: 3. Discuss the possibility of acquiring the product. If it's vital after all then it might not cost all that much, relatively speaking. If your client has the means, $1m might not be much to them but it should be cheaper than developing the product, porting the data and operating it for a time. Then your client gains a new revenue stream, a new (apparently very skilled) employee and the founder of the product gets a life changing amount of money. Everybody is happy.