Static analysis & you
Static analysis assists in identifying objectively inconsistent and problematic areas within your codebase. I think whether you're building a small application or a large one, there's immense value in static analysis.
Using open-source tools like Reek you can identify code smells that might have slipped through into your codebase and address them before they become a problem. I like to use Reek as both a learning tool and a reminder.
Flay is great for helping you identify abstractions once duplication has become apparent. Remember, Sandi Metz taught us that the wrong abstractions can be more dangerous than duplication so it is still up to us as experienced engineers to know when to ignore these tools.
Rubocop is awesome when it comes to identifying style-related infractions. It's easy to downplay how important code style is but consistency is the key here. I strongly believe in following community-derived conventions so my code is approachable by the widest audience of developers as is possible.
CodeClimate makes great use of all of the tools I've mentioned above and they have their own proprietary measure for assigning a GPA to your project as well as to individual files. I recommend considering it for your organization. If that sounds like overkill or you're like me and get excited about the opportunity to deploy something like this tailored to your specific needs you should check out Pronto.
I like to use static analysis to keep me on my toes and to enforce consistency in my own projects and in projects at work it's beneficial for the same reasons in addition to saving your engineers from having to manually point out these issues and avoid any potential friction. Consistency and craftsmanship go a long way in writing maintainable code.