"Full stack engineering interviews consist primarily of technical questions. Because full stack developers work with both back-end and front-end code, you should feel comfortable working with a variety of languages and answering questions ranging from databases and web servers to HMTL and UI implementation."
Design the DB and server system where multiple users can enter calendar events, including alerts for those events.
I designed the tables and columns I would need in a SQL database, and I wrote some pseudocode that would run in a cron job to send out alerts. I also wrote the SQL query to get all alerts that are pending. Once prompted, I added indexes and optimized the query.