QUOTE: “Cleaning up these kinds of link issue can take considerable time to be reflected by our algorithms (we don’t have a specific time in mind, but the mentioned 6-12 months is probably on the safe side). In general, you won’t see a jump up in rankings afterwards because our algorithms attempt to ignore the links already, but it makes it easier for us to trust the site later on.” John Mueller, Google, 2018
Ask for a technical and search audit for your site to learn what they think needs to be done, why, and what the expected outcome should be. You'll probably have to pay for this. You will probably have to give them read-only access to your site on Search Console. (At this stage, don't grant them write access.) Your prospective SEO should be able to give you realistic estimates of improvement, and an estimate of the work involved. If they guarantee you that their changes will give you first place in search results, find someone else.
QUOTE: “Medium pages achieve their purpose and have neither high nor low expertise, authoritativeness, and trustworthiness. However, Medium pages lack the characteristics that would support a higher quality rating. Occasionally, you will find a page with a mix of high and low quality characteristics. In those cases, the best page quality rating may be Medium.” Google Quality Evaluator Guidelines, 2017
By adding schema.org code to your pages in a new and innovative way, we are able to improve how Google, Pinterest and other platforms understand what your page is about. With Yoast SEO, you are now able to tell Google that your WebPage is an Article made by an Organization, and other combinations like that. This is the most convenient way for search engines to retrieve that information, and at this moment, Yoast is the only product or plugin offering this information this way! Others just tell Google it’s a webpage, an article and that there’s a brand, without connecting all together. This leaves a lot for Google to figure out itself. Only we tell the full story. If your website is about yourself (a Person), we’ll tell Google all the details you want Google to know, and also add your social profiles and more via that same schema.org data. This will definitely enhance your personal Knowledge Panel in Google and show these social profiles there as well, increasing your click-through chances due to that complete profile. This unique way of adding schema to your website will also connect with the schema.org data in our Local, Video or WooCommerce plugins, to make it all stunningly effective!
Smartphone - In this document, "mobile" or “mobile devices" refers to smartphones, such as devices running Android, iPhone, or Windows Phone. Mobile browsers are similar to desktop browsers in that they can render a broad set of the HTML5 specification, although their screen size is smaller and in almost all cases their default orientation is vertical.
If you are using Responsive Web Design, use meta name="viewport" tag to tell the browser how to adjust the content. If you use Dynamic Serving, use the Vary HTTP header to signal your changes depending on the user-agent. If you are using separate URLs, signal the relationship between two URLs by tag with rel="canonical" and rel="alternate" elements.
Ask for explanations if something is unclear. If an SEO creates deceptive or misleading content on your behalf, such as doorway pages or "throwaway" domains, your site could be removed entirely from Google's index. Ultimately, you are responsible for the actions of any companies you hire, so it's best to be sure you know exactly how they intend to "help" you. If an SEO has FTP access to your server, they should be willing to explain all the changes they are making to your site.