Sentry is an error-tracking tool that helps monitor and fix errors in real time. Error tracking and management tools such as Sentry distinguish themselves from traditional logging solutions such as the ELK Stack in their focus on discovering, investigating and fixing errors. Sentry has been around for some time and is quite popular — error-tracking tools are increasingly useful with the current focus on "mean time to recovery". Sentry — with its integration options with Github, Hipchat, Heroku, Slack, among other platforms — enables us to keep a close eye on our apps. It can provide error notifications following a release, enable us to track whether new commits actually fix the issue and alert us if an issue comes back due to a regression.