SEO penalty for dynamically generated website that uses multiple domains?

Question

I'm using a single NodeJS/Express server to dynamically generate marketing websites for my company's brand partners. In short, visitor hits one of these sites, I fetch some basic info from the database that corresponds with the URL they hit, then render a template server-side that gets sent to the requesting visitor. Visiting something like "www.FlyFoo.com" would generate different pricing and some different copy from "www.FlyBar.com", etc. according to the specific products/plans offered by that partner (served from the same server though). Most of the images, site layout, variable amounts of copy, etc will be the same. This data fetch and render is not done async, rather before the server actually responds to the initial request for the page.

Are we shooting ourselves in the foot here with SEO? Should I be architecting this with subdomains instead, then pointing domains like "www.FlyBar.com" to something like "flybar.baz.com". The decision to use separate domains was not mine, but I need some technical reasons to justify going back to the table and arguing for a different approach.

Note: I am developer/designer, but I have very little experience with SEO

Answer 1

dynamically generate marketing websites for my company's brand partners.

Although, I understand your question, I need to clarify this since this is usually not a common approach. Are you generating a page for each individual domain or generating a page for different section of the website?

Most of the images, site layout, variable amounts of copy, etc will be the same.

For different domains, if majority of stuff (including parts of content, if applicable) remains same then you aren't going in right direction with SEO if not "shooting ourselves in the foot".

Should I be architecting this with subdomains instead, then pointing domains like "www.FlyBar.com" to something like "flybar.baz.com".

Sub domains won't necessarily be of any benefit from escaping a possible plagiarism penalty (or content duplication). The core point being (and as you already understand), all the domains (or sub domains) essentially have same content in form of images, layout, etc.

Alternate approach:

Consider it as one possible approach. If your domains are spitting out same stuff for all domains and you are willing to stick on one parent domain (as suggested by possibility of using sub domains), why not throw in filters at www.FlyFoo.com and load appropriate filter using maybe JavaScript on pageload depending on what the user requests. You can replicate the specific request in url using parameters.