The sentence 'I hope you are doing good' is correct and usable in written English. You can use this phrase as a friendly or polite way to greet someone or inquire about their health and wellbeing. For example, you might write in a letter: "Hey there, I hope you are doing good. How have you been?".
I hope you're doing good.
So I hope you're doing okay.
I hope you're all doing good.
Now, you hope he'll be doing good on a consistent basis".
She's doing good, and I hope she keeps us".
We hope so -- girl's done good thus far... What do you think of Barbara Palvin?
Hope you're good bro".
Whatever you're doing, we hope you have a good weekend.
I hope his PR is doing a good job promoting this.
"I only hope they are doing them in enough depth to get good results.
He is yet to hear back but hopes he is doing some good for the cause.
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK