There are number of areas where scalability issues can come up. Most of them are usually due to not well optimized database queries. There was time when real-ti

There are number of areas where scalability issues can come up. Most of them are usually due to not well optimized database queries. There was time when real-time data subscriptions were too slow for me with Mongo but now you can seamlessly add Redis for that and bottleneck goes away. Any particular area you are concerned about?