What can I do to get on the radar of senior engineers within the company and build respect for me overall? My company is also relatively small, so I'm fairly close with the CTO as well.
Here's an example of an excellent pull request from when Taro was open-source.
I also highly recommend this Q&A on how to write great code faster.
Given we're a startup, other engineers on my team don't spend that much diligence on their code and code reviews. However, my CTO does really appreciate good code quality. All that being said, is this still the write thing to invest time in?
Yes! Really going deep on code quality is a very transferrable skill, and a lot of the code review "dressing" in particular (thinking through trade-offs, testing) is already done naturally during the coding process: You just need to "capture" this activity and embed it in your pull requests.
At all 3 of my previous companies (Course Hero, Meta, Robinhood), my extreme coding depth here was always met with very high praise. When I joined Course Hero, it was roughly the equivalent of a Series B startup, and this behavior of mine was very appreciated.
A lot of ambitious engineers will also eventually go to Big Tech, and this kind of behavior is extremely important there since it's so important to keep their massive systems clean and working.
Alex already made some great suggestions especially regarding code quality. I would add a few more