Experience is often measured in terms of time. The more time you've been in the industry means you got more experience. My definition of experience leaves time out of the equation though. I prefer a more logical approach.
Critical thinking
Taking into account the main objective and comparing possible solutions without the need to be right all the time is one of the qualities I believe an experienced individual to possess. They should be able to listen to different opinions and think about what's best for the end goal.
Calculated decisions
Technical skills are one thing. However, knowing that the business is what matters most and making decisions that benefit the business first is another important experience indicator. Less experienced individuals often prioritize technical requirements over functional ones.
Good reflexes
In the world of development, experienced engineers have the ability to foresee pros and cons of an implementation beforehand. They tend to train themselves on past mistakes to avoid repeating them. They will generally pause to think on even what most would consider petty, because they know that even the simplest implementation can be painful on the long run if not planned properly.
Humility
Humility is not a mere trait that exists on the surface. Being comfortable with not knowing everything is a powerful and healthy skill. A humble professional gives themselves the right to be wrong, hence they allow themselves to learn and grow painlessly. This also permeates to their colleagues, which makes for a sustainable working environment.
Ending note
In my career, I have come across developers with different years of service and most of the time, that was not proportional to their level of know-how. My hope is for employers and recruiters to look at the reality of this situation and make changes to their experience metrics.