I would say that it is not an issue of age, "many companies prefer to hire people in their 20's," as much as it is of cost.
The trend in most industries, and specifically in IT, is to hire the least expensive alternative in pure dollars, which is generally new graduates. If you are a bit older that will likely mean little, and, in fact, may be a slight advantage, provided your salary requirements are congruent with those of new graduates who are typically younger than yourself.
I have declined several jobs because the companies did not wish to pay for experience and I have lost others after two or three rounds of interviewing that went quite well because, in my 50s and with decades of experience which I expect to be paid for, my younger competitors are cheaper.
Employers should love the combination of maturity and economy of salary if my experiences over the past 5 to 10 years are any indication.
Brian AKA Bri the Tech Guy (website in my user profile) - Windows 10 Home, 64-Bit, Version 1803, Build 17134
. . . the presumption of innocence, while essential in the legal realm, does not mean the elimination of common sense outside it. The willing suspension of disbelief has its limits, or should.
~ Ruth Marcus, November 10, 2017, in Washington Post article, Bannon is right: It’s no coincidence The Post broke the Moore story