There's a lot of free and paid software, like Xenu Link Sleuth. These instruments can inform you what is not working on your site or what optimizations you can and should put in place. But there will always be a distinction between applying suggestions and understanding them. By understanding how to create and/or read a source code, you are generally less dependent on your software and apps, and above all you can assess the effect of these duties.
PHP helps reduce and automate certain duties
Knowing PHP can help you know how to evolve at a reduced level and hence enables you to automate or facilitate certain duties, such as changing a link database on all of its contents in a database, rapidly "searching / replacing" its publications. Briefly, it is helpful to know how to code. The SEO in 2019 is getting closer and closer to development they now need a technical background!
The SEO must be able to code
He must be able to comprehend his site's operation and source code if he wishes to be able to correct it. Without this, he loses some of the results that could carry his content and his incoming links. Worse still, poor code can simply stop the site from being correctly indexed by Google and other search engines.
The PHP header function
You can use the function header of the PHP language to handle this code yourself, for instance to inform GoogleBot or other robots that a website has been continuously transferred elsewhere on the site. It's very easy! For example, if your site has moved and you want to indicate the new address on the old home page, just write in the file at the old address.
An excellent SEO who understands php programming, will be able to produce and develop its own instruments, such as: client monitoring and/or placement ; content scraping ; spin ; detection of indexing or traffic issues ; setting up automatic user action corrections ; setting up tailor-made modules for pagination, indexing or inner networking.