By the time you’ve been working for more than 20 years, you know a few things. You know what you’re good at, what you enjoy, and what you’ve contributed to your job or industry. And if you happen to be out of work at the moment, you know that you need gainful employment, sooner than later, to maintain or improve on the life you’ve built. But there’s one thing that’s harder to know, because in mid-life and mid-career, we get used to thinking of ourselves in certain ways. That one thing is how others perceive you and your effectiveness in your work.

As a former corporate HR professional, I’ve observed how this particular gap in self-awareness can slow down career progress or a job search. Sure, performance reviews offer some feedback, but in general that feedback only comes from one direction—your boss, whose opinion is limited to what it’s like to manage you in your current job. Your subordinates, peers and clients can hold up a mirror as well, offering a more complete picture of who you are at work. How to get those multiple perspectives? Enter the 360-degree feedback assessment, a data gathering process designed to glean information about your strengths and weaknesses from a wide range of people—a 360-degree view—for the purpose of your development and improvement. Not everyone has the luxury of going through this process at work, or having your company pay for it. But nearly anyone who is open-minded and motivated to learn and grow can benefit. Better yet, it’s absolutely possible to do a modified, DIY 360.

Darryl Simon, founder and president of Vantage Growth Strategic Advisors, is an organizational development expert and executive coach who has been conducting professional 360-degree assessments for 20 years. He’s currently seeing an uptick in midlife career changers in the market, and the process can be a great eye-opener for re-inventers. “We all have blind spots,” he says, “Sometimes it takes an outside perspective to put a spotlight on something we’re not aware of. It’s a very collaborative world we live in—the more self-awareness we have, the more effective we can be.”