[Syssiphus]

From the top of my head..:

The Praetorian Bootcamp challenges are similar to the Matasano ones: https://www.praetorian.com/challenges/

Lisp Koans: https://github.com/google/lisp-koans

Project Euler: https://projecteuler.net/

Exercism: http://exercism.io/

99 Lisp Problems: http://www.ic.unicamp.br/~meidanis/courses/mc336/2006s2/func...

[monkeyshelli]

I've been using python-koans to teach Python, but the thought of looking for lisp-koans from Github didn't even cross my mind now as I personally started learning CL. Thanks for these excellent links!

[doomrobo]

the Lisp Koans, Exercism, and 99 Lisp problems look especially good for FP concepts (and the first two are more modern than I had expected). Thanks!