Covering some basic topics I haven't seen elsewhere on Cody.
Return a cell array of all MATLAB keywords
It would be better if the solution didn't contain the answer. Also, in the problem statement you should probably specify that the keywords must be sorted alphabetically (and appear only once each). Otherwise a cell array such as {'if', 'for', 'else', ...} would satisfy the problem statement, but fail the Test Suite — as demonstrated in Solution 1329165.
Extract leading non-zero digit
886 Solvers
564 Solvers
223 Solvers
How many trades represent all the profit?
434 Solvers
Implement simple rotation cypher
764 Solvers