Use virtual servers
Instead of using a dedicated server for each project, and loading it up to 20% of its capability, pool machine resources through a hypervisor. One physical machine can offer the same service as 4 dedicated servers at 20%. This optimizes the use of the processor and RAM while consuming less electricity than multiple physical servers. This method also reduces the amount of electronic waste (WEEE) generated by the website.
Generate PDFs outside of the CMS
Generating PDFs on-the-fly uses enormous amounts of CPU and RAM. Consequently, do not generate PDFs to order, page by page, but instead offer a few files generated and optimized outside of the CMS