The talk gives an overview of various optimisations implemented in strace over the past several years. While most of them are quite trivial (like caching of frequently-used data or avoiding syscalls whenever possible), some of them are a bit more tricky (like usage of seccomp BPF programs for avoiding excessive ptrace stops) and/or target more specific use cases (like the infamous thread queueing patch[1], which was carried as a RHEL downstream patch for almost 10 years).
[1] https://gitlab.com/strace/strace/commit/e0f0071b36215de8a592bf41ec007a794b550d45