TL;DR — Distributed Task Scheduler

Design a distributed task scheduler that supports cron-based recurring jobs, one-time delayed execution, and priority-based task queuing. Think of systems like Airflow, Celery, or Uber's Cherami. The scheduler must guarantee exactly-once execution, support retries with exponential backoff, and handle worker failures gracefully. Key features: Schedule one-time tasks for future execution with second-precision. Define recurring tasks using cron expressions with timezone support.