That's because someone who can build you a server from barebones hardware to a running system in the cloud, waiting to accept and serve data won't pick a framew

That's because someone who can build you a server from barebones hardware to a running system in the cloud, waiting to accept and serve data won't pick a framework to write the application; they are unlikely to even use JavaScript for the backend part, because they learned their lessons. What you have are conflicting requirements. You have to work on those first, or hire someone with 20-30 years of experience, pay them appropriately and trust them.