Use your knowledge to build the Common Lisp track itself
Help create the track syllabus: is a set of concepts and learning exercises put together to teach foundational elements of the programming language.
Create Test Runners that have the single responsibility of taking a solution, running all tests and returning a standardized output.
Build an Analyzer for Common Lisp: Exercism's analyzers automatically assess student's submissions and provide mentor-style commentary.
Build a Representer: a bit of code that has the single responsibility of taking a solution and returning a normalized representation of it.
Practice Exercises are exercises designed to allow students to solve an arbitrary problem, with the aim of them making use of the concepts they have learned so far.