WebTuna Software Ltd is closely related to Application Performance Ltd (it shares directors). Application Performance specialises in selling application performance monitoring (APM) products. So you would expect WebTuna to use APM tools and we do. It is known colloquially as eating your own dog food. In other words, practising what you preach.
We make extensive use of AppDynamics (Java and database in our case) and OverOps (formerly Takipi). Recently we used AppDynamics to identify interference between overnight batch jobs in production that were causing locking problems in the database. By moving one of the batch jobs by a few minutes we were able to eliminate the lock waits. We were alerted to the problem by one of our synthetic agents, testing the website throughout the day and night. It was only a small blip that might have gone unnoticed without monitoring.
We use OverOps to analyse exceptions thrown by Java. Mostly these come from bad input data but we use the information to continually improve the robustness of WebTuna.
Finally, WebTuna is an end-user experience (EUM) monitoring tool in its own right. We use WebTuna to monitor the performance of all the AP and WebTuna websites. Just as you might analyse the performance of the pages in your website, we do the same for our websites.