I'm building a fantasy football app and am unsure whether everything should live at XYZ.com or whether the public marketing site should use XYZ.com while the logged-in product runs at app.XYZ.com. Some well-known products use the main domain for both their landing pages and application, while others separate those experiences. I've also heard arguments that subdomains can improve security, make it easier to host the marketing site separately, and allow different teams to work independently. On the other hand, keeping everything together could simplify authentication, cookies, routing, and the user experience. This seems like a decision that could be inconvenient to change later, so what approach would you recommend for a new product?
5 Answers
A subdomain becomes useful when the two parts need to be managed independently. For example, a marketing team could use a separate static hosting provider while developers deploy the application separately. It can also provide some isolation and allow the marketing site to remain available if the app has an outage, but those benefits aren’t usually essential for an early-stage product.
Don’t choose based on vague SEO claims. Search engines generally treat subdomains separately, so putting public marketing content on the main domain may be simpler for building one content and analytics structure. A logged-in app usually contributes little to SEO anyway. For your situation, I’d prioritize the simplest authentication, routing, deployment, and cookie setup.
There’s no universal rule here. If you don’t have a concrete reason to separate the app, putting the marketing pages and product under the main domain is perfectly reasonable. You can always introduce a subdomain later if the teams, hosting, or architecture need to split.
This isn’t necessarily a permanent decision. You can move an app to a subdomain later with redirects and a careful authentication migration. Start with the structure that keeps development and user navigation straightforward, then split the systems when there’s an actual operational reason rather than trying to predict every future problem.
A common setup is to use the main domain for marketing and have the app appear there after login. That keeps the experience simple and avoids making users remember a second address. It works especially well when the marketing site and app use the same stack and authentication system.
That separation can also make future ownership changes easier. If another company takes over the marketing site, they can work on it without needing access to the application code or release process.