Used PM2 and Keymetrics in my last start up job. I feel like PM2 is must for App because of features provided. Keymetrics is little bit costly. You can find other solutions as well but PM2 and Keymetrics is good combination overall.
We're using Spark on EMR with Data Pipeline to do ETL and to run Scheduled Jobs. Data pipelines terminates the cluster once ETL or job gets completed, helps us a lot to save cost.