I have worked in digital marketing for more than 16 years, and one thing I have learned is that many SEO problems are created before an SEO specialist ever gets involved. Developers make decisions about URLs, site structure, rendering, navigation, redirects, templates, and performance because they are building the product. Those decisions can have a major impact on organic search later, even when SEO was never part of the original development plan.
SEO is often treated as something to add after a website launches. The development team builds the product, everything works, and then marketing is asked to optimize it. By that point, some of the decisions that matter most for search visibility have already been made.
I experienced this while building GamesMom. One of the decisions that created extra work later was our URL structure. We initially organized some content under categories because it seemed like a logical way to structure the site. As the website grew, we decided that individual resources would work better with a flatter URL structure.
A good example is our chess content. The page now lives at https://gamesmom.com/chess-for-kids/, but it previously lived under https://gamesmom.com/brain-games/chess-for-kids/. The new structure made more sense as the site evolved, but changing URL architecture after launch created considerably more work than it would have before launch.
