We are a small team planning a new website plus ongoing SEO work, and I am not sure whether to hire one agency for everything or split the tasks between specialists. How do you usually decide which approach makes more sense?

I went through this last year and what helped me most was reading the individual service pages instead of the general pitch on the homepage. If custom software, website development and SEO each have their own explanation of scope and process, that usually says more than any promise about growth, and it is worth checking that level of detail yourself, you can view it here, before you send any request. So what do you personally look at first when one company covers design, development and marketing at once? Do you ask for examples of past work in your exact niche, or is a clear description of the workflow, timelines and what is included enough for you to move forward?