None. Just apply for an open positipn early enough and if your grades were well in this lwcture you will get the job. Might help adding some previous recommendation letter.
Other Teaching Assistant Interview Reviews for ETH Zurich
Informal discussion solely based on my academical performance. For most courses this is not competitive and quite easy to get in. Depending on the lecturer this can be kind of a technical interview, or a informal get together.
In preparation to the interview I was asked to prepare a mock lesson for the subject. The interview then started with this mock lesson, with the interviewer taking the role of a student.
Interview questions [1]
Question 1
How I would prepare a lesson and explain a subject to students