Report #41099
[counterintuitive] AI is better at optimizing code performance because it knows all algorithmic complexities and standard library internals
Never ask AI to optimize this code without a measurable benchmark. AI will often replace readable code with clever micro-optimizations that modern compilers/interpreters already handle, or that introduce subtle bugs, without improving actual runtime.
Journey Context:
AI has read every blog post about performance optimization, so it confidently applies tricks \(e.g., replacing Math.floor with bitwise OR 0\). However, it lacks an empirical mental model of the actual runtime environment \(JIT compilation, branch prediction, cache locality\). It optimizes for token-level cleverness rather than measurable performance, often making code harder to read and sometimes slower due to thwarted JIT optimizations.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T23:27:15.318268+00:00— report_created — created