Asked

Do you launch on all platforms in one go? Or one by one?

Don't think it matters unless you are not sure about how well your server can scale πŸ˜‚

Decentralization evangelist, Entrepreneur, Life hacker, Backend engineer. Cyberpunk @ Woodpckr.com | Building AirGapped Crypto Vault live on stream
Freelance Software Engineer, India + Remote

It depends. If I am skeptic about the product/idea/implementation, I tend to launch it on one platform first, just to check what the general public feedback about it, is.
When that is done, I launch it on other platforms simultaneously.
This is sort of a safe approach, it saves you from a complete launch fail, but also, on the other hand, prevents your product from reaching its full virality potential.
I did it with #vscodenotebook I was unsure about it so I only launched it only on Reddit. It went quite well and I lost the chance of going more viral than it actually went. πŸ˜‚