Researcher in telecommunications. Why not?
Once I had to write a programme for a micro-controller, in assembler. No development tool available. No computer. Wrote the programme and compiled it by hand. Inserted the result byte by byte in the ROM. Put the ROM on the board. OK, not working of course... At the end of the day, it was working. Coding is a combat sport.
Coding is a combat sport. You have to practice to strengthen yourself.
Reading good books is indispensable. Not enough.
Many have concerns about on-line sites proposing problems to be solved.
It is a pity that these sites don't promote good coding practices, to tell the less.
But participating in these challenges is better than doing nothing. Better than discouraging beginners to participate: insist that it is quite possible to submit good and fast solutions respecting good practices.
I spent decades in my work trying to help beginners. Much much easier to teach them good coding practices than to teach them how to address and analyse a difficult problem.