Some perf numbers from Google.<p>&gt;LinkedIn is a prominent user. Their entire mobile stack is built on Node.js. They went from running 15 servers with 15 instances on each physical machine, to just 4 instances – that can handle double the traffic!<p>&gt;eBay launched ql.io, a web query language for HTTP APIs, which uses Node.js as the runtime stack. They were able to tune a regular developer-quality Ubuntu workstation to handle more than 120,000 active connections per node.js process, with each connection consuming about 2kB memory!