There's lots of good stuff here, but while your code might not be the most important aspect of your SaaS startup, your code can't be garbage either. I've seen lots of startups and early-stage businesses rot from the inside because of bad coding practices and not being able to deliver features in a timely manner or what they do deliver is broken and buggy, driving customers away.

If you can't deliver the features your customers need because of shit code, that really does matter.