The trick is to precompute the Redis command strings whenever possible. We (not going to name names here) use Redis at above that scale. Our keys all have a fix

The trick is to precompute the Redis command strings whenever possible. We (not going to name names here) use Redis at above that scale. Our keys all have a fixed size, so we preallocate a buffer that can hold the command and the key, clear (so move the write pointer back to the beginning of the key) it on every new request, write directly into the buffer, and then pass a pointer to the buffer when writing to the socket. This is a similar trick we use whenever we're constructing load tests as a lot of the time can be spent creating request bodies instead of just pushing bytes onto the socket as fast as possible.