When they ask “how did you hear about the position?”, the interviewer just wants to know if you’ve taken the time to research the company and if you have a genuine reason for wanting to talk with them. Mention a product, a mission statement on the website, a reputation for talented employees, or whatever else seems applicable to that specific company. Come up with a great reason. Don’t make it seem like they’re just one company among many. Or that you’re sending your resume out to them for no particular reason other than wanting a job.
Tip: This might be one of the most important questions asked during the interview process because it allows you to explore any subject that hasn’t been addressed and shows the interviewer you’re excited about the role. By this point, you’ll likely have already covered most of the basics about the position and the company, so take time to ask the interviewer questions about their own experiences with the company and gain tips on how you can succeed if hired.
Any candidate can read and regurgitate the company’s “About” page. So, when interviewers ask this, they aren't necessarily trying to gauge whether you understand the mission—they want to know whether you care about it. Start with one line that shows you understand the company's goals, using a couple key words and phrases from the website, but then go on to make it personal. Say, “I’m personally drawn to this mission because…” or “I really believe in this approach because…” and share a personal example or two.