Well, every particular case has its own explanation. For example, there's rather hype topic in career industry connected with AI, its different chatbots that help recruiters to contact and sent quick answers to applicants, it's Google Careers - https://careers.google.com/, and Leap.ai -https://leap.ai/, launched by ex-Googlers, that helps job seekers in their job search, ATS systems that help in processing resumes, and AI career builder - https://skillroads.com/, that helps get all application documents ready and provides interview help. All these systems use different algorithms and learn from the previous experience.