#1 advice for engineer-founders is to always be questioning whether coding is the best leveraged use of your time.
As a bootstrapped engineer founder, I spent way too many months (years?) coding non-stop, even after we got past PMF, despite having the revenue to hire engineers to replace me day-to-day. These days I do zero coding, and am still equally happy and fulfilled. At least for me, spending days coding was a really easy way to feel productive, but it wasn't the best use of time compared to hiring, marketing, sales, company culture, etc.
#2 advice for founder-engineers: after you're able to stop coding, remember that your product is worthless if no one knows about it or if no one is using it. Once you get product market fit into a good place and have revenue traction, it's time to spend your nights thinking about marketing and sales rather than code.
TLDR: always make sure you're spending your time in the most highly leveraged areas. Hiring and delegating. Coding is rarely the highest leveraged area your time can be spent.