I've been a data guy for first half of my career in service company and was mainly using sql and gui etl tools. However in the second half I started to move towards R and Python for data engineering and science stuff. Although exploratory coding is fine with me I find real time coding during interviews very grinding. Any suggestions to overcome that. I'm a data scientist at age 38.
If you've been doing it for some time, I suggest going to hard ones now. Time box to 40 minutes in coming up with a solution. If you can't make progress beyond that time, look at discussion for solution. Understand the solution and add a tag to revisit it in one month. After one month try to solve it again with code accepted by oj. Spend no more than 1.5 hours total on each question on your first attempt.