At HackerRank we use Redis Pub/Sub as a pipeline to help all developers practicing on HackerRank to see the results of their code submission in near real-time. We use RedisJSON heavily in this pipeline to detect the status of all submissions and inform our users so they can better compete in our programming challenges. This has worked very well for us for several years without any issues at an extremely large scale to meet our need to process thousands of code submissions per minute.
