&gt; CloudFlare&#x27;s firewall system uses LuaJIT to analyse approximately 4 million GET requests per second.<p>While I agree with your premise (LuaJIT is a pretty awesome project), this example means nothing in terms of performance.<p>— &quot;analyse&quot; doesn&#x27;t give an indication of the workload -- it could vary from &quot;matching against a precompiled regexp&quot; to running advanced statistical models.<p>— 4 millions requests per second does not mean anything without knowing the size of the deployment. You can always throw more hardware at a &quot;trivially&quot; parallelizable problem.<p>— Throughput is only one dimension on the &quot;speed&quot; continuum, latency (and especially tail latency) is also very important. Some languages have very good throughput and fail hard at tail latency (Java, Go until recently). Some others have lower throughput but more predictable latency.