I have made the transition from a engineering manager to IC last year. I had spent 3 years as a EM and that was long enough to lose significant amount of day to day knowledge around engineering. I did 3 months of Leetcode and I got a role a Senior Software Engineer.
Would I do it again, no unless it was within my current company. Jumping to another company after not being hands on for a few years was very difficult. Especially when it came to the system design questions.
Edit: Now that I've made the transition, its great. It was a slow start with the coding aspects. The management background helps a lot for interactions with my peers and junior developers. My peers already think I should be at least the next level in the IC track, but that is probably because I take on responsibilities outside my immediate area.
I have used hackerrank/leetcode previously just sporadically to learn a new programming language. I used it for the first time to help me get another job earlier in the year.
However, I have continued to solve 1 problem a night because what I realised is after 15+ years in the industry, I don't have a good grasp of some concepts anymore.
I'm slowly getting better at identify types of problems and apply what could be the most efficient data structure/algorithm in solving the problem. Once I solve the problem I go have a look at the solutions to see a more efficient way of solving it and try to store it away in my memory banks for another day.
The thing I don't like is when interviewer asks follow ups such as "Can you do the same solution but using O(1) space complexity". Unless the job has a restriction on running on limited hardware resources. I feel like it's unjustified asking such follow up questions because most of the time that is a very specific solution for the problem - or maybe I'm just not good enough to come up with such a solution yet.
Would I do it again, no unless it was within my current company. Jumping to another company after not being hands on for a few years was very difficult. Especially when it came to the system design questions.
Edit: Now that I've made the transition, its great. It was a slow start with the coding aspects. The management background helps a lot for interactions with my peers and junior developers. My peers already think I should be at least the next level in the IC track, but that is probably because I take on responsibilities outside my immediate area.