Quoting Ken Jin

Python 3.15's JIT compiler has hit its performance targets over a year ahead of schedule on macOS AArch64 (11-12% faster than the tail-calling interpreter) and a few months early on x86_64 Linux (5-6% faster than the standard interpreter). The milestone puts the JIT back on track after earlier uncertainty about its inclusion. Meaningful news given Python's dominance in AI/ML workloads, though the gains are modest and won't reshape day-to-day AI development work.