Search friendly design is mostly a matter of not breaking things that work by default. A plain, fast, well structured page is readable by search engines without effort. Most damage is done by design decisions that hide content, slow the page or replace text with images, and it is much cheaper to avoid those than to remediate them.
What design actually controls
Design decides whether content is text or an image, whether important content is behind an interaction that delays or hides it, whether heading structure reflects meaning or just size, whether navigation is crawlable, and how heavy the page is. Those are the levers. Everything else that gets called technical SEO in a design context is downstream of them, which is why a designer who understands this saves more than a specialist retained afterwards.
Speed is a design decision before it is an engineering one
Large hero imagery, multiple typefaces, embedded video that loads immediately, and animation libraries are chosen in design and paid for in performance. Google documents what a well built page delivers, including good Core Web Vitals, HTTPS, proper mobile display and no intrusive interstitials. Set a performance target during design and test the heaviest template on a real mid range phone before the design is approved rather than after it is built.
Interstitials and overlays are the common self inflicted wound
Cookie banners, newsletter overlays, app install prompts and chat widgets are all design decisions, and stacked together they obstruct the content a visitor came for on a small screen. Google explicitly names intrusive interstitials that obstruct content as working against page experience. Decide during design how many interruptions a page is permitted and in what order, because nobody decides this later and they accumulate.
One supplier or two: a website designer and SEO specialist
A designer with genuine search literacy is more valuable than a separate specialist auditing afterwards, because the expensive mistakes are made during design. A combined supplier, an SEO friendly web design company, is efficient when the work is a site build; separate suppliers make sense when search is an ongoing program rather than a project. Google's own guidance on hiring an SEO is a sane reference for what to expect from either, and it is notably unimpressed by guarantees.
Questions people ask about SEO webdesign
What makes SEO friendly web designs work?
Mostly not breaking defaults: real text rather than images, important content not hidden behind interactions, headings that reflect meaning, crawlable navigation, and a page that is not heavy. A plain fast page is readable without effort.
Should one SEO designer handle both the design and the search work?
A designer with real search literacy prevents the expensive mistakes, which are made during design. A combined supplier suits a site build; separate suppliers suit an ongoing search program.
Do cookie banners and popups hurt?
Stacked together they obstruct the content visitors came for, particularly on small screens, and Google names intrusive interstitials that obstruct content as working against page experience. Decide the interruption budget during design.