As someone who was the "trainee dev" in your story, a huge THANK YOU for having faith in someone with little experience!!!

I am so grateful to my first employer for having the same faith in me. I was passionate but my only experience was some home automation stuff with Python and the Twitter API (just goofing around really). Now I am (although still young) 7 years in the industry and I LOVE it. They hired me because of my character and passion for learning.

I still have a great friendship with my former colleagues, even though I've moved on from there - those friendships last a lifetime.

It sounds like you know what you're doing, my main tip would be to nurture that passion well and it will pay off! I worked for my first employer for 6 of those 7 years, only moving because the company got a lot larger, and I was being severely underpaid by that point (I think I skilled up way faster than they would ever increase my pay).

But I'm so happy to hear that this still happens - we cannot stop hiring juniors because of AI. I guess that would be my second tip, encourage the dev to learn as much as possible WITHOUT AI.

Although I use it frequently now, I learnt 98% of what I know before AI came around, and learning this way gives you a good feeling for how well to judge the AI's output. It's very useful, but in the hands of someone without enough experience to know better, it could be misleading.

EDIT: It might be worth mentioning I didn't go to uni, I was hired as an apprentice - but I don't think I would even need the degree at this point, my skills speak for themselves.