This post describes how I learned to think "customer first" from an early mentor unexpectedly.
Early in my career while still an individual contributor, I was regularly in closed contact with a rather important customer. And sometimes, I felt they were way too demanding. Whether or not that was correct is not of interest here.
I was rather angry and went to see my boss at the time. And I'd freak out a little, venting my anger in his office. He would listen carefully, not saying a word. Just letting me vent what I needed to get off my chest.
And then he'd say: "Yeah, you're right. And that's why in the end we'll write an invoice for it." (paraphrasing here).
That situation stuck in my mind for years to come. And it was the single most important event that made me adopt a customer first mindset. Yes, the customer may have been wrong. Yes, they may have been too demanding. But ultimately, they were paying my salary.
As an engineer, I found it often that many customers I had the pleasure to meet, didn't really know what they needed. More often than not, they mostly knew what was hurting them and what they wanted to see solved. If you're the one coding the solution in the end, you very much prefer to be part of the solution design to make sure that no incidental complexity is created in the design. And if you're like me, than maybe you won't trust anybody else's solutions too much early in your career. Because, of course I knew much better at the time 🙃.
But once I got over all that. Accepted that the customer doesn't have to be right, doesn't have to tell me solution, I could adopt a mindset that would allow me to think about their problems first. Adjusting my perspective from the work I would have to do towards what was hurting them.
Ever since, I put the customer's challenges and problems first, and my own (or my employer's) concern second. Yes, they need to go together. But first, I think about the problem that needs solving.
Another thing, I learned from that interaction with my mentor was: Sometimes as a people manager you just need to let your team members vent off. They don't always expect a solution from you. They just want to be heard. And there's no judging in such a conversation. It's about getting rid of the unsuitable, unhelpful, angry, inconvenient and blocking emotions. Create a safe space for such conversations and never, ever share anything that has been said in that space.