diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index a35ae1124..b7f4aaa95 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -31,6 +31,21 @@ codegen-units = 1
 panic = "unwind"
 opt-level = "z"
 
+# Per-package opt-level overrides (Straw speed audit, S5). The whole tree stays
+# size-optimized ("z"), but the JS-interpreter + parsing hot paths run measurably
+# slow at "z" — QuickJS's C bytecode interpreter, the regex DFA engine, and JSON
+# deserialization are all tight inner loops where "z" trades real runtime for a
+# few KB. Bumping ONLY these three to opt-level = 2 bounds the APK-size cost to
+# these crates while restoring interpreter/parse throughput. Crate names verified
+# present in Cargo.lock: rquickjs-sys (QuickJS C interpreter, compiled via cc),
+# regex-automata (regex execution engine, pulled by `regex`), serde_json.
+[profile.release.package.rquickjs-sys]
+opt-level = 2
+[profile.release.package.regex-automata]
+opt-level = 2
+[profile.release.package.serde_json]
+opt-level = 2
+
 # `url` crate for video-id extraction in stream.rs.
 [workspace.dependencies]
 url = "2"