I've been optimizing a large SaaS website for a few years now and found that the biggest gains were on the payment pages and pricing pages at the end of the funnel.

That being said, for this particular site, there were glaring usability issues with the site and poor content on the pages so it was the obvious choice of a place to start.

To find places that you can make the biggest impact, after you've fixed any glaring usability issues, look in Google Analytics for pages with high exit rate percentages. These are pages that people had issues, if you can answer their objections then you're one step closer to a conversion.

If you'd like advice specifically tailored to your website I'd be happy to help. Give me a call here - https://clarity.fm/domlinder