I'm guilty of that sort of thing as well (doing something complex without enough training to properly code it). Story time to drive home my points: I started 7

I'm guilty of that sort of thing as well (doing something complex without enough training to properly code it). Story time to drive home my points: I started 7 years ago, fresh out of uni with a diploma, but not enough experience, and did something overly complex, with a lot of frankly bad code. Then, 5 years ago, we expanded the team (which means I was no longer the sole developer, but we were now 2). At first, I was not satisfied with the other developer (fresh out of uni as well). Instead of trying to fire him, I bit the bullet and answered every question, took a lot of time to explain things to him. Yes it slowed me a lot. It also forced me to up my game to make our codebase readable (not MY code, our codebase), add comments etc... In the end, he is now a valuable team member (we are still only 2 devs, with the occasional intern) who knows most of the codebase as well, if not better, than me. It has been the case since about 3 years (it took him 6 months to have a decent development speed, and about 2 year to develop at about the same speed as me). Neither of us consider himself a "rockstar" developer and that's fine. We work as a team, and as a result our code is better, faster, more readable and as less bugs. I couldn't achieve that level alone no matter how much I tried. To sum up: train them relentlessly, without loosing patience, and use that as an opportunity to make the codebase more readable. You didn't mention how much time those engineers have been working with you though. Common knowledge is that it takes at least about 3 months to be proficient with a codebase you are new to. More if you are not experienced.