Recently I passed the recertification exam for the AWS Solution Architect Associate. It took me roughly about 1 month to prepare for it. It was way easier than in 2018 when I took this exam for the first time. Cloud is a very dynamic environment and lots of new services come up every year, but the fundamentals remain the same. Because of that, I was starting from some level of knowledge and I needed only to refresh it and learn new things.
In addition, there are more training materials available than in 2018. My main resource was a course created by Stephane Maarek on the Udemy platform. I’ve also heard lots of good opinions about materials created by Adrian Cantrill, but I haven’t tested them by myself.