This talk will cover the need of a centralized logging system, showcasing the architecture of the system. Also, I talk about how we ended up building this centralized logging system, What was the need for such a system, what problems we faced, how MongoDB fits into this and what others can learn from this. I also covered some how can we use mongoDB to make our logging system for realtime analytics and alerting system . The major use case of this system it to keeping track of meaningful events. This could be -: 1. How many users registered ? 2. How many registrations fails ? 3. Most occurred errors while doing something. 4. Realtime Analytics and Alerts 5. Identifying the possible threats.