System design interview question
"Design a distributed job scheduler. Users submit jobs — some to run once at a specific time, some on a recurring cron schedule, some immediately. Workers pick them up and execute them. Jobs must not be lost, must not run twice when they should run once, and some jobs depend on others finishing first. Millions of jobs a day."
reliable execution semantics under failure, plus efficient time-based dispatch. The three specific hard parts are: firing a job at the right time without scanning a huge table every second, guaranteeing a job is not executed twice by two workers, and handling a worker that dies mid-execution.
On Practick another engineer interviews you live for 60 minutes on a question from this bank. They have the full interviewer guide beside the call: the answers to your clarifying questions, the numbers to hand out, a ladder of follow-ups and a scoring rubric. You get the model solution once the session settles. It is free: interview someone for an hour and you have earned your own.
Book a free mock interviewAll 132 system design interview questions
System design mock interviews · DSA interview questions · Free mock interview practice · Browse interviewers · Sign in