very low or non-existent domain ratings.

How do you determine this? It's not a Google ranking factor.

I mention this because I know most people rely on those fake metrics Domain Authority and Page Authority. But those are made up. You shouldn't be making business decisions on those factors.

The truth is you don't know what value Google has given those sites. And the fact that Google hasn't flagged any indicates that your metrics are not helping much.

I would move on and ignore the links. There are no issues because nothing has been flagged by google.

Whether the previous developer paid for the links or not is also a non-issue.
dietpepsisucks ✍️
It looks like Ahref's Domain Rating and URL Rating metrics are proprietary to their software, so that's a very good point.

I worked in-house for a large corporation for a number of years, and I created a lot of high-quality content specifically for backlinking purposes, and I was taught 'quality over quantity' when it came to backlinking for Search Engine Optimization (SEO).

Thank you so much for your help!
emuwannabe
The quality over quantity thing is disputable. I know lots of people swear by it, but I've been doing link building for 20 years and you'd be surprised how Google actually applies it's quality rating.

Hint: Its very generous.

It's like the "relevant and related" section of link building. Now of course we want high quality links from relevant and related sites, but that doesn't mean they ALL have to be relevant OR related. Or, to put another way, the relationships between sites/links can be very broad. If you are a roofer you aren't stuck to just going after roofing related links. Really any trade related link is a good link, as are flooring stores, lumber yards and tradespeople directories.

I typically don't mess with backlinks too often. I usually focus on writing website content,

I'm not trying to be rude here… but why are you doing a backlink audit if you don't normally mess with backlinks?

brb going to take someones appendix out. No idea how or why but I'll give it a go.
dietpepsisucks ✍️
I spent a number of years creating high-quality content specifically for backlinking purposes. I worked with other SEO professionals and we rarely had issues with backlink spam.

I've read conflicting information all over the place about paid backlinks and backlink spam. Do I keep hundreds of backlinks that lead to broken pages or NSFW sites? Or do I wait until Google penalizes the website
GrumpLife
It's not as easy as you think for Google to give a manual penalty. Most of the time, they just ignore the garbage now. If they penalized every site that had shitty backlinks, it'd be pretty easy to crush your competition.

The best course of action here is to document that the 'bad backlinks' existed before you took the project on. Let the owner know but there's no need to alarm them. Mention it in passing and let them know that you work on a professional level and will not be focusing on that type of backlinking.