I thought Shenzhen was more hardware than software no?

The biggest internet company in China, Tencent, is in Shenzhen.

Also one of the most modern banks, China Merchant's Bank (招商银行 / CMBC) is headquartered there.

I need to open a bank account in China next month - out of curiosity, in what way are they one of the most modern? :)

Not one of the old guard from the socialist era, a generally good reputation / better service, and first to have relatively OK internet banking. (ie. not 'manually reconfigure your windows certificates' like some others used to be)

Silicon Valley started out being about hardware with HP, Intel, etc.

DJI is in Shenzhen as well.