Is LinkedIn Sharing Your Application History and Interest Level with Recruiters?

    • With many companies now using LinkedIn’s Easy Apply feature, it seems possible that recruiters are leveraging LinkedIn data at the screening stage. This might even extend to applications submitted via company websites if you include your LinkedIn profile link.

    • Could LinkedIn be sharing details about your past application activity? For instance, if someone has applied to dozens of jobs in a short time, could recruiters see this and potentially flag (or even blacklist) the candidate as a “mass applicant”? While I haven’t found direct sources confirming this, it seems like a data point recruiters would find valuable.

    • There’s also chatter that LinkedIn may indicate your level of interest in a company—like how often you’ve visited their LinkedIn page. This seems to align with some anecdotal evidence from users.

Yes your data is being shared but not exactly how you may think. Keep in mind that all of your points so far are stated in the Terms of Service you agree to when you use LinkedIn even if LinkedIn may not be currently engaged in that behavior.

There is a partial summary of how in https://www.linkedin.com/legal/privacy-policy and https://learn.microsoft.com/en-us/linkedin/. It is partial because any third-party involved in your application has their own terms.
Here are some things to highlight:

• Customers and partners may provide data to us.
  • Partners
    • We receive personal data (e.g., your job title and work email address) about you when you use the services of our customers and partners, such as employers or prospective employers and applicant tracking systems providing us job application data.
  • Related Companies and Other Services
    • We receive data about you when you use some of the other services provided by us or our Affiliates, including Microsoft. For example, you may choose to send us information about your contacts in Microsoft apps and services, such as Outlook, for improved professional networking activities on our Services
• Service Use
  • We log your visits and use of our Services, including mobile apps.
    • We log usage data when you visit or otherwise use our Services, including our sites, app and platform technology, such as when you view or click on content (e.g., learning video) or ads (on or off our sites and apps), perform a search, install or update one of our mobile apps, share articles or apply for jobs. We use log-ins, cookies, device information and internet protocol (“IP”) addresses to identify you and log your use.
• Sites and Services of Others
  • We get data when you visit sites that include our ads, cookies or plugins or when you log-in to others’ services with your LinkedIn account.
    • We receive information about your visits and interaction with services provided by others when you log-in with LinkedIn or visit others’ services that include some of our plugins (such as “Apply with LinkedIn”) or our ads, cookies or similar technologies
• Partners
  • We receive personal data (e.g., your job title and work email address) about you when you use the services of our customers and partners, such as employers or prospective employers and applicant tracking systems providing us job application data.

About the only thing they don't do (according to them) is share LinkedIn client data with other LinkedIn clients. The language is intentionally broad otherwise.

Understand I am not sharing a personal stance or opinion, I'm trying to summarize the ToS and Privacy Policy the way a layperson may be interested.
For example: if there is a native way to be tracked then it is a part of the service itself and if the service itself doesn't have the option to turn off tracking then the only other option is to delete your account. You can block third-party scripts and cookies but you can't block LinkedIn from offering a feature or an API.

If you review the LinkedIn API documentation as well has how popular ATS and CRM services market themselves you will see your last point is indeed a feature of the website. In general, many popular social media use a variety of fingerprinting techniques that an ATS or CRM service may use.

Also remember that most people aren't using a browser with secure popup blockers and robust anti-fingerprinting. If you don't have something similar to Firefox and uBlock Origin there are many ways your data is being collected which you aren't regularly interacting with. Even with those you can't change things that are server side.