Cold messages to people in my field, do they work? - 8 months and counting

A friend suggested informational chats and I do not know how to ask. I worked as a software tester before this. Some people reply with short answers.

I asked what they wish they had known at my stage. People enjoy answering that.

I wrote three short lines: who I am, why them and a small ask for fifteen minutes. About one in four said yes.