diff --git a/crates/cactus-sys/build.rs b/crates/cactus-sys/build.rs
index 00e0b5f802..721018d26c 100644
--- a/crates/cactus-sys/build.rs
+++ b/crates/cactus-sys/build.rs
@@ -1,74 +1,111 @@
 use std::env;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 fn main() {
-    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
-    let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
-    let workspace_root = manifest_dir.parent().unwrap().parent().unwrap();
-    let vendor_dir = workspace_root.join("vendor").join("cactus");
-    let cactus_src_dir = vendor_dir.join("cactus");
+    let cactus_src = locate_cactus_source();
+    set_rebuild_triggers(&cactus_src);
+    apply_linux_compiler_workaround();
+
+    let build_dir = build_native_library(&cactus_src);
+    link_native_library(&build_dir);
+    link_platform_dependencies();
+
+    generate_bindings(&cactus_src);
+}
+
+fn locate_cactus_source() -> PathBuf {
+    let path = env::var("CACTUS_SOURCE_DIR")
+        .map(PathBuf::from)
+        .unwrap_or_else(|_| char_workspace_fallback());
 
     assert!(
-        cactus_src_dir.exists(),
-        "Cactus source not found at {cactus_src_dir:?}. Run: git submodule update --init --recursive"
+        path.exists(),
+        "Cactus source not found at {path:?}. Set CACTUS_SOURCE_DIR or run: git submodule update --init --recursive"
     );
 
+    path
+}
+
+fn char_workspace_fallback() -> PathBuf {
+    let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+    manifest_dir
+        .ancestors()
+        .nth(2)
+        .unwrap()
+        .join("vendor/cactus/cactus")
+}
+
+fn set_rebuild_triggers(cactus_src: &Path) {
+    println!("cargo:rerun-if-env-changed=CACTUS_SOURCE_DIR");
     println!("cargo:rerun-if-changed=wrapper.h");
     println!(
         "cargo:rerun-if-changed={}",
-        cactus_src_dir.join("ffi").join("cactus_ffi.h").display()
+        cactus_src.join("ffi/cactus_ffi.h").display()
     );
+}
 
-    // GCC on Linux doesn't include <iomanip> transitively through <sstream>,
-    // but cactus/telemetry/telemetry.cpp uses std::setfill/setw without including it.
-    #[cfg(target_os = "linux")]
-    {
-        let existing = env::var("CXXFLAGS").unwrap_or_default();
-        let patched = if existing.is_empty() {
-            "-include iomanip".to_string()
-        } else {
-            format!("-include iomanip {existing}")
-        };
-        // Safety: build scripts run in an isolated process.
-        unsafe { env::set_var("CXXFLAGS", patched) };
-    }
+#[cfg(target_os = "linux")]
+fn apply_linux_compiler_workaround() {
+    // GCC requires explicit <iomanip>; upstream telemetry.cpp omits it.
+    let existing = env::var("CXXFLAGS").unwrap_or_default();
+    let cxxflags = if existing.is_empty() {
+        "-include iomanip".to_string()
+    } else {
+        format!("-include iomanip {existing}")
+    };
+    unsafe { env::set_var("CXXFLAGS", cxxflags) };
+}
+
+#[cfg(not(target_os = "linux"))]
+fn apply_linux_compiler_workaround() {}
 
-    let dst = cmake::Config::new(&cactus_src_dir)
+fn build_native_library(cactus_src: &Path) -> PathBuf {
+    cmake::Config::new(cactus_src)
         .define("BUILD_SHARED_LIBS", "OFF")
         .define("CMAKE_BUILD_TYPE", "Release")
         .build_target("cactus")
-        .build();
+        .build()
+        .join("build")
+}
 
-    println!(
-        "cargo:rustc-link-search=native={}",
-        dst.join("build").display()
-    );
+fn link_native_library(build_dir: &Path) {
+    println!("cargo:rustc-link-search=native={}", build_dir.display());
     println!("cargo:rustc-link-lib=static=cactus");
+}
 
-    #[cfg(target_os = "macos")]
-    {
-        println!("cargo:rustc-link-lib=framework=Metal");
-        println!("cargo:rustc-link-lib=framework=MetalPerformanceShaders");
-        println!("cargo:rustc-link-lib=framework=Accelerate");
-        println!("cargo:rustc-link-lib=framework=Foundation");
-        println!("cargo:rustc-link-lib=framework=CoreML");
-        println!("cargo:rustc-link-lib=curl");
-        println!("cargo:rustc-link-lib=c++");
+#[cfg(target_os = "macos")]
+fn link_platform_dependencies() {
+    for framework in [
+        "Metal",
+        "MetalPerformanceShaders",
+        "Accelerate",
+        "Foundation",
+        "CoreML",
+    ] {
+        println!("cargo:rustc-link-lib=framework={framework}");
     }
+    println!("cargo:rustc-link-lib=curl");
+    println!("cargo:rustc-link-lib=c++");
+}
 
-    #[cfg(target_os = "linux")]
-    {
-        println!("cargo:rustc-link-lib=stdc++");
-        println!("cargo:rustc-link-lib=m");
-        println!("cargo:rustc-link-lib=pthread");
-        println!("cargo:rustc-link-lib=curl");
-    }
+#[cfg(target_os = "linux")]
+fn link_platform_dependencies() {
+    println!("cargo:rustc-link-lib=stdc++");
+    println!("cargo:rustc-link-lib=m");
+    println!("cargo:rustc-link-lib=pthread");
+    println!("cargo:rustc-link-lib=curl");
+}
+
+#[cfg(not(any(target_os = "macos", target_os = "linux")))]
+fn link_platform_dependencies() {}
 
-    let wrapper_path = manifest_dir.join("wrapper.h");
+fn generate_bindings(cactus_src: &Path) {
+    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+    let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
 
-    let bindings = bindgen::Builder::default()
-        .header(wrapper_path.to_str().unwrap())
-        .clang_arg(format!("-I{}", cactus_src_dir.display()))
+    bindgen::Builder::default()
+        .header(manifest_dir.join("wrapper.h").to_str().unwrap())
+        .clang_arg(format!("-I{}", cactus_src.display()))
         .clang_arg("-x")
         .clang_arg("c++")
         .clang_arg("-std=c++20")
@@ -78,9 +115,7 @@ fn main() {
         .derive_debug(true)
         .derive_default(true)
         .generate()
-        .expect("failed to generate bindings");
-
-    bindings
+        .expect("failed to generate bindings")
         .write_to_file(out_dir.join("bindings.rs"))
         .expect("failed to write bindings");
 }
diff --git a/crates/cactus-sys/src/lib.rs b/crates/cactus-sys/src/lib.rs
index 0cf64d2a30..83ce996302 100644
--- a/crates/cactus-sys/src/lib.rs
+++ b/crates/cactus-sys/src/lib.rs
@@ -1,7 +1,9 @@
-#![allow(non_upper_case_globals)]
-#![allow(non_camel_case_types)]
-#![allow(non_snake_case)]
-#![allow(dead_code)]
-#![allow(clippy::all)]
+#![allow(
+    non_upper_case_globals,
+    non_camel_case_types,
+    non_snake_case,
+    dead_code,
+    clippy::all
+)]
 
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));