Some can, some can't. We hired a mid 40s candidate right out of coding boot camp. He was obviously smart and a hard worker and got along with everyone very well. It took 2.5 years to convince the boss that he wasn't making progress, and to let him go. In all that time his coworkers, including me, spent many hours, days and weeks patiently helping him, training him, essentially doing most of his work. But it just never clicked with him and he never gained the ability to do more than the simplest debugging.

Another older coding camp grad, who happened to be an immigrant woman, was a natural engineer who learned our complex systems very rapidly, contributed a lot quickly, and soon moved on to higher paying opportunities.

You will hear lots of encouraging words here and hopefully they will be true for you. But beware of wasting years on this project if you find that after giving it a solid try, it still doesn't suit. It just isn't for everone.