At work we make plentiful use of Lua on our telephony backend. As part of many dial plans we need to invoke certain "scripty" functionality - stuff that runs to

At work we make plentiful use of Lua on our telephony backend. As part of many dial plans we need to invoke certain "scripty" functionality - stuff that runs top to bottom to do one thing and then return - which may require e.g. database access, RabbitMQ interaction, Memcached key wrangling etc., and Lua's fast start-up and executional speed facilitates this for us on large scale better than almost anything else. We initially began with Python for some of these things, which quickly became an untenable and elaborately consummated performance disaster. There are plenty of techniques to get around its slow start-up and performance issues, but they come with a slew of new complications compared to the simplicity and ability to quickly deploy/update/execute from local file system. Lua for us makes the difference of being able to, on one and the same piece of hardware, manage a thousand simultaneous phone calls instead of just a few hundred.