Large-scale websites performance optimisation tricks

Practical lessons learned while revamping a US airline website to resist huge Black Friday and Cyber Monday traffic values. Using HTTP status codes and PHP cleverly, we have made parallel requests possible, so that the user experience is greatly enhanced, and we pre-cache resource-consuming user searches. All on a solid Drupal + Symfony2 foundation. Technical insight of a case study of a large airline that has rebuild its web-facing components using Drupal, Symfony2, and Javascript SPAs. Participants will have a low understanding of architectural principles behind building large-scale applications, and will have learned what are the pitfalls and how they can be avoided.