Disclosed are systems, methods, and non-transitory computer-readable media for automated. VM performance tuning. An auto-tuning system implements a three stage automated VM performance tuning process to optimize garbage collection. In the first stage, the auto-tuning system analyzes garbage collection logs to calculate garbage collection parameters to configure the new generation portion of the memory heap (e.g., maximum tenuring age, maximum new size and survivor ratio). In the second stage, the auto-tuning system implements the calculated garbage collection parameter and monitors garbage collection activity for the VM to determine the resulting effects. In the third stage, the auto-tuning system tunes the old generation portion of the memory heap based on the monitored garbage collection activity. Specifically, the auto-tuning system determines a promotion rate from the monitored garbage collection activity and then determines a total memory heap size based on the promotion rate to achieve a target major garbage collection rate.