Start from here: https://github.com/jwasham/coding-interview-university

When studying from this, choose only to learn the optimal data structures and algorithms, understand why the other solutions are bad and then find out where these concepts are applied in several open-source projects.

Once you have completed the essentials, solve the puzzles in Hackerrank and Leetcode, before the interview.

To be honest, I dislike this sort of interviewing for DS/Algos unless the company can justify using them other than for a secret IQ test or another candidate filtering technique. If it were me, I'd just ask for links to significant open-source contributions instead of this nonsense.