"What is the Full Circle Matchmaker scheduled job and what does it do?"
If you or your Salesforce administrator monitors the scheduled jobs or Apex jobs pages in your Salesforce organization, you may notice that there is a dedicated scheduled job for Full Circle Insights. You will also see that there are queueable classes that run rather frequently, the main one being LAM_AsyncBatcher.
By design, the Full Circle scheduled job runs every minute and picks up background tasks that would otherwise go unprocessed. These tasks are processed via the LAM_AsyncBatcher; this class is executed every minute even if there are no tasks to process.
This is perfectly acceptable and expected behavior. There are many background processes that run asynchronously in Full Circle Matchmaker in order to allow users to perform their day-to-day job functions without hitting Salesforce limits or errors. Because we know that a customer may have many other managed packages, workflow rules, processes, flows, and custom Apex logic that all operate on lead and account updates, we defer a lot of our application processing to occur “behind the scenes” instead of real-time. Some of these operations include: lead matching (including bulk lead matching), lead assignment, lead conversion, and account email domain calculations.
In summary, you need not worry about Full Circle causing problems in your org by running a lot of background processing – in fact, we actually do this to prevent issues from happening. As the limit of the number of asynchronous executions per 24-hour window is at minimum 250,000*, our background processing should have minimal impact on this limit.
*Apex Developer Guide: Execution Governors and Limits - https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_gov_limits.htm