i've come a long way of understanding the purpose of existence and i thought to lay down the conclusions. These are not original ideas but the result of putting together ideas from leading thinkers (e.g. philosophers).
So here we go.
Life has no purpose in itself only we, people, we're giving it one.
Life is just what happened as a result of natural selection rules describe by Charles Darwin.
We don't have a specific role to fulfill for the well being of the Universe.
So the first thing to note is that each one of us should find its own purpose in life. My personal take on this is that we, as a species, should evolve in order to find better solutions to our biggest problems.  There is no shortage of problems that needs to be solved just to have a better chance at surviving on long term instead of becoming extinct as dinosaurs did.
Since we want to apply these philosophical thoughts in our day to day life we must keep in mind that our skills are not equal for all of us. Even if we can acquire new skills one will be better at some stuff and worse at others. So my approach is that you use the skills you have and improve of that instead of trying to fix  a lot of the others you are very bad at.
Now connecting the dots we should contribute to the evolution of the humankind in the domain where we can according to our skills.
To put it as simply as we can, we should find the job that we like and have the skills for and do it well. We should be proactive so instead of just doing what we are asked for to try to find any other thing that we may find important to do to improve our product.
We should also change the job when this is not driving the improvement of our skills anymore.
There is a huge gap between solving the biggest problems of humankind and doing well some job but even so i think there's at least a sketch of connecting the higher purpose with the rather ordinary one.
So we would be happier if we would just do our job well having in mind the direction that we should all evolve in order to be better equipped for tackling the biggest problems.
The idea of advancing in career is wide spread but what i want to stress is the reason or direction of doing it. That is not for money or status but ultimately for the future of our kind.
And since we're not all Einstein we should do it step by step. First we train our own skills, then we evolve our team and if we are really capable can spread the knowledge in our industry/field