When I was coding full time I always followed a simple principal: if you really love this system and want it to succeed even after you leave the company, then keep it as simple as possible - sure, you could condense those ten lines into some unintelligible masterpiece, but right now they could be understood by any other developer, and if you really want that code to live a long life then just make sure there’s no barrier to entry for the next person who maintains it. If they’re junior, they’ll still be able to maintain it and if they’re a rock star they’ll get what you were up to.