diff --git a/compiler/hash-link/src/linker/mod.rs b/compiler/hash-link/src/linker/mod.rs
index 925060891..fb913c540 100644
--- a/compiler/hash-link/src/linker/mod.rs
+++ b/compiler/hash-link/src/linker/mod.rs
@@ -1,6 +1,7 @@
 //! Defines a generic linker interface and functions that create
 //! an instance of a [Linker] with the provided compiler settings
 //! and target options.
+#![allow(dead_code)] // @@Temporary: remove when all linker methods are used.
 
 use std::{
     ffi::{OsStr, OsString},
diff --git a/compiler/hash-lower/src/lib.rs b/compiler/hash-lower/src/lib.rs
index b3bad2344..2c61bda6d 100644
--- a/compiler/hash-lower/src/lib.rs
+++ b/compiler/hash-lower/src/lib.rs
@@ -204,7 +204,7 @@ impl<Ctx: LoweringCtxQuery> CompilerStage<Ctx> for IrOptimiser {
         let bodies = &mut icx.bodies;
         let body_data = &icx.ctx;
 
-        self.time_item("optimise", |_| {
+        self.time_item("optimise", |this| {
             // @@Todo: think about making optimisation passes in parallel...
             // pool.scope(|scope| {
             //     for body in &mut icx.generated_bodies {
@@ -218,6 +218,10 @@ impl<Ctx: LoweringCtxQuery> CompilerStage<Ctx> for IrOptimiser {
             for body in bodies.iter_mut() {
                 let optimiser = Optimiser::new(body_data, settings);
                 optimiser.optimise(body);
+
+                // Collect metrics on the stages.
+                let metrics = optimiser.into_metrics().into();
+                this.metrics().merge(&metrics);
             }
         });
 
diff --git a/compiler/hash-lower/src/optimise/cleanup_locals.rs b/compiler/hash-lower/src/optimise/cleanup_locals.rs
index 3fa88d0df..267c2dd2d 100644
--- a/compiler/hash-lower/src/optimise/cleanup_locals.rs
+++ b/compiler/hash-lower/src/optimise/cleanup_locals.rs
@@ -29,7 +29,7 @@ pub struct CleanupLocalPass;
 
 impl IrOptimisationPass for CleanupLocalPass {
     fn name(&self) -> &'static str {
-        "cleanup_locals"
+        "optimise::cleanup_locals"
     }
 
     /// Pass [CleanupLocalPass] is always enabled since it performs
diff --git a/compiler/hash-lower/src/optimise/mod.rs b/compiler/hash-lower/src/optimise/mod.rs
index d8a375374..d76979faf 100644
--- a/compiler/hash-lower/src/optimise/mod.rs
+++ b/compiler/hash-lower/src/optimise/mod.rs
@@ -8,6 +8,7 @@
 
 use hash_ir::{ir::Body, IrCtx};
 use hash_pipeline::settings::{CompilerSettings, OptimisationLevel};
+use hash_utils::timing::{CellStageMetrics, HasMetrics};
 
 // Various passes that are used to optimise the generated IR bodies.
 mod cleanup_locals;
@@ -40,6 +41,9 @@ pub struct Optimiser<'ir> {
     /// The various passes that have been added to the optimisation
     /// pipeline.
     passes: Vec<Box<dyn IrOptimisationPass + Send>>,
+
+    /// Metrics for each of the passes.
+    metrics: CellStageMetrics,
 }
 
 impl<'ir> Optimiser<'ir> {
@@ -51,6 +55,7 @@ impl<'ir> Optimiser<'ir> {
                 Box::new(simplify_graph::SimplifyGraphPass),
                 Box::new(cleanup_locals::CleanupLocalPass),
             ],
+            metrics: CellStageMetrics::default(),
         }
     }
 
@@ -59,8 +64,20 @@ impl<'ir> Optimiser<'ir> {
     pub fn optimise(&self, body: &mut Body) {
         for pass in self.passes.iter() {
             if pass.enabled(self.settings) {
-                pass.optimise(body, self.store);
+                self.time_item(pass.name(), |this| {
+                    pass.optimise(body, this.store);
+                })
             }
         }
     }
+
+    pub fn into_metrics(self) -> CellStageMetrics {
+        self.metrics
+    }
+}
+
+impl HasMetrics for Optimiser<'_> {
+    fn metrics(&self) -> &CellStageMetrics {
+        &self.metrics
+    }
 }
diff --git a/compiler/hash-lower/src/optimise/simplify_graph.rs b/compiler/hash-lower/src/optimise/simplify_graph.rs
index b981524b2..f00efb9af 100644
--- a/compiler/hash-lower/src/optimise/simplify_graph.rs
+++ b/compiler/hash-lower/src/optimise/simplify_graph.rs
@@ -94,7 +94,7 @@ pub struct SimplifyGraphPass;
 
 impl IrOptimisationPass for SimplifyGraphPass {
     fn name(&self) -> &'static str {
-        "simplify-graph"
+        "optimise::simplify_graph"
     }
 
     fn enabled(&self, settings: &CompilerSettings) -> bool {