Explore the four main levels of parallelism in modern computing through this informative conference talk from EuroPython 2019. Dive into multiple virtual machines, processes, threads, and green threads (asyncio) in Python. Learn why and how to use each level of parallelism, with code examples demonstrating RQ, RPC with HTTP, multiprocessing, threading, and asyncio with AIOHTTP. Discover potential pitfalls and "gotchas" associated with each approach, including communication challenges between processes, limitations of threading and the GIL, and the complexities of combining different types of concurrency. Gain insights into tools like runemin/emexecutor and the speaker's own library, arq, for efficient job queueing and RPC using asyncio and Redis. Enhance your understanding of parallel programming possibilities in Python to optimize your code for modern computing environments.