**Neither a teacher nor a native speaker.**
I asked a similar question a while ago.
My opinion:
When you talk about a company, use the 3rd person singular.
Microsoft develops software. :up:
When you don't say the company's name, replace the word by they!
They develop software. :up:
I highly suggest you not to use this construction:
It develops software. :down:
Of course a company usually consists of people, but when you talk about the company itself, you summarize them, which makes it possible to handle it as a singular word.
But remember: Company name = Singular; No name = Plural -> They
Cheers!