In this chapter, we have provided you with a number of seemingly unconnected cases that you may or may not have the luck to face for real. We have quickly recapped on the most popular troubles with SSL/TLS certificates that webmasters encounter starting from the most embarrassing expiration to building a whole caching proxy for external insecure content. We have also described a number of cases with caching, URL rewriting rules migration, file-upload progress interfaces, and concluded with the mystery of an idle upstream. The next chapter is devoted to building a proper monitoring system for your Nginx-powered servers. We will move from solving problems to actively preventing them.