Has anyone here worked with a full service digital agency that covers marketing, SEO and web development at once? I am trying to understand if one team for everything really works better than hiring separate specialists for each part.

We are at the stage where the website needs a full rebuild and the SEO side has been ignored for years, so I keep going back and forth between one agency and a group of freelancers. How do you usually judge whether a single team can handle custom software, website development and search optimization at the same level? I went through one agency page that lists all of these services together, here is the page I mean, and even with a clear structure I still cannot tell from a service list how deep the actual experience goes. What do you ask about first in a case like this, past projects, the internal process, or the way they scope the work before giving any numbers? And how much detail is reasonable to expect before the first call?