diff --git a/experiments/001_hello_world/lib b/experiments/001_hello_world/lib
new file mode 120000
index 0000000..565e254
--- /dev/null
+++ b/experiments/001_hello_world/lib
@@ -0,0 +1 @@
+../shared/lib
\ No newline at end of file
diff --git a/experiments/002_chromium_sandbox/lib b/experiments/002_chromium_sandbox/lib
index 207813e..565e254 120000
--- a/experiments/002_chromium_sandbox/lib
+++ b/experiments/002_chromium_sandbox/lib
@@ -1 +1 @@
-../001_hello_world/lib
\ No newline at end of file
+../shared/lib
\ No newline at end of file
diff --git a/experiments/003_wasm_compile/.gitignore b/experiments/003_wasm_compile/.gitignore
index 43dc8bc..4c5a0db 100644
--- a/experiments/003_wasm_compile/.gitignore
+++ b/experiments/003_wasm_compile/.gitignore
@@ -10,7 +10,7 @@ python-raw/wit_world/
 python-raw/componentize_py_types.py
 python-raw/componentize_py_async_support/
 python-raw/poll_loop.py
-rust/target/
+rust-hello/target/
 as-hello/node_modules/
 as-hello/build/
 __pycache__/
diff --git a/experiments/003_wasm_compile/Makefile b/experiments/003_wasm_compile/Makefile
index ef4ac17..0ace639 100644
--- a/experiments/003_wasm_compile/Makefile
+++ b/experiments/003_wasm_compile/Makefile
@@ -1,12 +1,14 @@
-.PHONY: deps build test bench bench-quick clean help
+.PHONY: deps build build-js build-py build-rust build-as test bench bench-quick clean help
 
 CONTAINER_CMD ?= $(shell command -v podman 2>/dev/null || echo docker)
-VENV          := .venv
-COMPONENTIZE  := $(VENV)/bin/componentize-py
+GIT_ROOT      := $(shell git rev-parse --show-toplevel)
+VENV          := $(GIT_ROOT)/.venv
+ACTIVATE      := . $(VENV)/bin/activate &&
+BUILD_DIR     := build
 
 $(VENV)/bin/activate: requirements.txt
-	python3 -m venv $(VENV)
-	$(VENV)/bin/pip install --quiet -r requirements.txt
+	uv venv --clear $(VENV)
+	uv pip install --quiet -r requirements.txt
 	@touch $(VENV)/bin/activate
 
 deps: $(VENV)/bin/activate  ## Install toolchain dependencies (spin, componentize-py, hey)
@@ -16,34 +18,52 @@ deps: $(VENV)/bin/activate  ## Install toolchain dependencies (spin, componentiz
 	brew install hey
 	@echo "✓ deps ready  (componentize-py in $(VENV); JS deps fetched at build time by spin build)"
 
-build: $(VENV)/bin/activate  ## Compile all sources to .wasm
+build: build-js build-py build-rust build-as  ## Compile all sources to .wasm → build/
+	@echo "✓ All .wasm artifacts in $(BUILD_DIR)/"
+
+build-js:  ## Build JS → .wasm (Spin)
 	@echo "→ Building JS (Spin)..."
 	cd js-spin && spin build
+	@mkdir -p $(BUILD_DIR)
+	cp js-spin/dist/hello-js.wasm $(BUILD_DIR)/hello-js-spin.wasm
+
+build-py: $(VENV)/bin/activate  ## Build Python → .wasm (componentize-py + Spin)
+	@mkdir -p $(BUILD_DIR)
 	@echo "→ Building Python/raw (componentize-py)..."
-	cd python-raw && ../$(COMPONENTIZE) -d wit -w proxy componentize app -o hello-py-raw.wasm
+	cd python-raw && VIRTUAL_ENV= $(VENV)/bin/componentize-py -d wit -w example:hello/proxy --all-features componentize app -o hello-py-raw.wasm
+	cp python-raw/hello-py-raw.wasm $(BUILD_DIR)/hello-py-raw.wasm
 	@echo "→ Building Python (Spin)..."
-	cd python-spin && spin build
+	cd python-spin && $(ACTIVATE) spin build
+	cp python-spin/app.wasm $(BUILD_DIR)/hello-py-spin.wasm
+
+build-rust:  ## Build Rust → .wasm (cargo wasm32-wasip2)
 	@echo "→ Building Rust baseline..."
-	cd rust && cargo build --target wasm32-wasip2 --release --quiet
+	cd rust-hello && cargo build --target wasm32-wasip2 --release --quiet
+	@mkdir -p $(BUILD_DIR)
+	cp rust-hello/target/wasm32-wasip2/release/leg3.wasm $(BUILD_DIR)/hello-rust.wasm
+
+build-as:  ## Build AssemblyScript → .wasm (asc + wasm-tools)
 	@echo "→ Building AssemblyScript (asc + wasm-tools)..."
-	cd as-hello && npm ci --silent 2>/dev/null && ./build.sh
-	@echo "✓ All .wasm artifacts built"
+	cd as-hello && npm ci --silent && ./build.sh
+	@mkdir -p $(BUILD_DIR)
+	cp as-hello/build/hello-as.wasm $(BUILD_DIR)/hello-as.wasm
 
 test:  ## Run BATS unit tests
 	bats tests/
 
-bench:  ## Run full 6-leg benchmark
+bench:  ## Run full 7-leg benchmark
 	./benchmark.sh
 
 bench-quick:  ## Quick benchmark (10 requests)
 	HEY_N=10 ./benchmark.sh
 
 clean:  ## Remove build artifacts
+	rm -rf $(BUILD_DIR)
 	rm -rf $(VENV)
 	rm -rf js-spin/node_modules js-spin/build js-spin/dist
 	rm -f python-spin/app.wasm
 	rm -f python-raw/hello-py-raw.wasm
-	rm -rf rust/target
+	rm -rf rust-hello/target
 	rm -rf as-hello/node_modules as-hello/build
 	$(CONTAINER_CMD) rmi -f hello-js-spin hello-py-spin 2>/dev/null || true
 
diff --git a/experiments/003_wasm_compile/benchmark.sh b/experiments/003_wasm_compile/benchmark.sh
index 19a5b22..9534bda 100755
--- a/experiments/003_wasm_compile/benchmark.sh
+++ b/experiments/003_wasm_compile/benchmark.sh
@@ -225,7 +225,7 @@ run_leg3() {
   require_port_free 5035 "Leg 3"
   command -v cargo &>/dev/null || fail "cargo not found"
 
-  pushd "$SCRIPT_DIR/rust" >/dev/null
+  pushd "$SCRIPT_DIR/rust-hello" >/dev/null
     APP_3=$(human_size src/lib.rs)
     BUILD_3=$(timed_build "cargo wasm32-wasip2" \
       cargo build --target wasm32-wasip2 --release --quiet 2>/dev/null)
diff --git a/experiments/003_wasm_compile/lib b/experiments/003_wasm_compile/lib
index 207813e..565e254 120000
--- a/experiments/003_wasm_compile/lib
+++ b/experiments/003_wasm_compile/lib
@@ -1 +1 @@
-../001_hello_world/lib
\ No newline at end of file
+../shared/lib
\ No newline at end of file
diff --git a/experiments/003_wasm_compile/python-spin/app.py b/experiments/003_wasm_compile/python-spin/app.py
index 07c1cdd..a12d1a5 100644
--- a/experiments/003_wasm_compile/python-spin/app.py
+++ b/experiments/003_wasm_compile/python-spin/app.py
@@ -1,19 +1,19 @@
 import json
 import time
 
-from spin_sdk import http
-from spin_sdk.http import Request, Response
+from spin_sdk.http import IncomingHandler, Request, Response
 
 
-def handle_request(request: Request) -> Response:
-    body = json.dumps(
-        {
-            "message": "Hello World",
-            "timestamp": time.time(),
-        }
-    )
-    return Response(
-        200,
-        {"content-type": "application/json"},
-        bytes(body, "utf-8"),
-    )
+class IncomingHandler(IncomingHandler):
+    def handle_request(self, request: Request) -> Response:
+        body = json.dumps(
+            {
+                "message": "Hello World",
+                "timestamp": time.time(),
+            }
+        )
+        return Response(
+            200,
+            {"content-type": "application/json"},
+            bytes(body, "utf-8"),
+        )
diff --git a/experiments/003_wasm_compile/python-spin/spin.toml b/experiments/003_wasm_compile/python-spin/spin.toml
index 22827aa..b236cd4 100644
--- a/experiments/003_wasm_compile/python-spin/spin.toml
+++ b/experiments/003_wasm_compile/python-spin/spin.toml
@@ -14,5 +14,5 @@ source = "app.wasm"
 allowed_outbound_hosts = []
 
 [component.hello-py.build]
-command = "../.venv/bin/componentize-py -d wit -w proxy componentize app -o app.wasm"
+command = "componentize-py -w spin-http componentize app -o app.wasm"
 watch = ["app.py"]
diff --git a/experiments/003_wasm_compile/requirements.txt b/experiments/003_wasm_compile/requirements.txt
index 8ea3771..438c236 100644
--- a/experiments/003_wasm_compile/requirements.txt
+++ b/experiments/003_wasm_compile/requirements.txt
@@ -1 +1,2 @@
-componentize-py
+componentize-py>=0.17,<0.18
+spin-sdk>=3.4,<4
diff --git a/experiments/003_wasm_compile/rust b/experiments/003_wasm_compile/rust
deleted file mode 120000
index f261943..0000000
--- a/experiments/003_wasm_compile/rust
+++ /dev/null
@@ -1 +0,0 @@
-../001_hello_world/leg3_wasmtime
\ No newline at end of file
diff --git a/experiments/003_wasm_compile/rust-hello/Cargo.lock b/experiments/003_wasm_compile/rust-hello/Cargo.lock
new file mode 100644
index 0000000..bd8eb65
--- /dev/null
+++ b/experiments/003_wasm_compile/rust-hello/Cargo.lock
@@ -0,0 +1,43 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "bitflags"
+version = "2.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
+
+[[package]]
+name = "leg3"
+version = "0.1.0"
+dependencies = [
+ "wasi",
+]
+
+[[package]]
+name = "wasi"
+version = "0.14.7+wasi-0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "883478de20367e224c0090af9cf5f9fa85bed63a95c1abf3afc5c083ebc06e8c"
+dependencies = [
+ "wasip2",
+]
+
+[[package]]
+name = "wasip2"
+version = "1.0.2+wasi-0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9517f9239f02c069db75e65f174b3da828fe5f5b945c4dd26bd25d89c03ebcf5"
+dependencies = [
+ "wit-bindgen",
+]
+
+[[package]]
+name = "wit-bindgen"
+version = "0.51.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7249219f66ced02969388cf2bb044a09756a083d0fab1e566056b04d9fbcaa5"
+dependencies = [
+ "bitflags",
+]
diff --git a/experiments/003_wasm_compile/rust-hello/Cargo.toml b/experiments/003_wasm_compile/rust-hello/Cargo.toml
new file mode 100644
index 0000000..1c0b266
--- /dev/null
+++ b/experiments/003_wasm_compile/rust-hello/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "leg3"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+wasi = "0.14"
diff --git a/experiments/003_wasm_compile/rust-hello/run.sh b/experiments/003_wasm_compile/rust-hello/run.sh
new file mode 100755
index 0000000..61e16c7
--- /dev/null
+++ b/experiments/003_wasm_compile/rust-hello/run.sh
@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+PORT=5003
+DIR="$(cd "$(dirname "$0")" && pwd)"
+
+# Ensure Rust/cargo is on PATH — respects CARGO_HOME (XDG-compliant)
+export PATH="${CARGO_HOME:-${XDG_DATA_HOME:-$HOME/.local/share}/cargo}/bin:$PATH"
+
+command -v cargo    &>/dev/null || { echo "✗ cargo not found — install rustup" >&2; exit 1; }
+command -v wasmtime &>/dev/null || { echo "✗ wasmtime not found — brew install wasmtime" >&2; exit 1; }
+
+# Ensure wasm32-wasip2 target is available
+if ! rustup target list --installed 2>/dev/null | grep -q "wasm32-wasip2"; then
+  echo "→ Adding wasm32-wasip2 Rust target..."
+  rustup target add wasm32-wasip2
+fi
+
+cd "$DIR"
+
+echo "→ Building Rust WASM component (wasm32-wasip2)..."
+cargo build --target wasm32-wasip2 --release 2>&1
+
+WASM=$(find target/wasm32-wasip2/release -maxdepth 1 -name "*.wasm" | head -1)
+if [ -z "$WASM" ]; then
+  echo "✗ No .wasm file found in target/wasm32-wasip2/release/" >&2
+  exit 1
+fi
+echo "→ Binary: $WASM ($(du -sh "$WASM" | cut -f1))"
+
+echo "→ Starting wasmtime serve on port $PORT..."
+wasmtime serve -S cli --addr "127.0.0.1:$PORT" "$WASM" &
+WASMTIME_PID=$!
+
+# Wait for readiness
+echo -n "→ Waiting for HTTP..."
+for i in $(seq 1 30); do
+  if curl -sf "http://127.0.0.1:$PORT/" &>/dev/null; then
+    echo " ready"
+    curl -s "http://127.0.0.1:$PORT/" | python3 -m json.tool
+    wait "$WASMTIME_PID"
+    exit 0
+  fi
+  sleep 0.2
+done
+
+echo " timeout" >&2
+kill "$WASMTIME_PID" 2>/dev/null || true
+exit 1
diff --git a/experiments/003_wasm_compile/rust-hello/src/lib.rs b/experiments/003_wasm_compile/rust-hello/src/lib.rs
new file mode 100644
index 0000000..3f2e2fe
--- /dev/null
+++ b/experiments/003_wasm_compile/rust-hello/src/lib.rs
@@ -0,0 +1,33 @@
+use wasi::clocks::wall_clock;
+use wasi::exports::wasi::http::incoming_handler::Guest;
+use wasi::http::types::{Fields, IncomingRequest, OutgoingBody, OutgoingResponse, ResponseOutparam};
+
+struct Component;
+
+impl Guest for Component {
+    fn handle(_request: IncomingRequest, response_out: ResponseOutparam) {
+        let now = wall_clock::now();
+        let ts = now.seconds as f64 + (now.nanoseconds as f64 / 1_000_000_000.0);
+        let body_str = format!(r#"{{"message":"Hello World","timestamp":{ts:.6}}}"#);
+
+        let headers = Fields::new();
+        headers
+            .append(&"content-type".to_string(), &b"application/json".to_vec())
+            .unwrap();
+
+        let response = OutgoingResponse::new(headers);
+        response.set_status_code(200).unwrap();
+
+        let out_body = response.body().unwrap();
+        {
+            let stream = out_body.write().unwrap();
+            stream
+                .blocking_write_and_flush(body_str.as_bytes())
+                .unwrap();
+        }
+        OutgoingBody::finish(out_body, None).unwrap();
+        ResponseOutparam::set(response_out, Ok(response));
+    }
+}
+
+wasi::http::proxy::export!(Component with_types_in wasi);
diff --git a/experiments/003_wasm_compile/tests/test_003.bats b/experiments/003_wasm_compile/tests/test_003.bats
index a3ae30c..181a102 100644
--- a/experiments/003_wasm_compile/tests/test_003.bats
+++ b/experiments/003_wasm_compile/tests/test_003.bats
@@ -1,23 +1,31 @@
 #!/usr/bin/env bats
 # Experiment 003 — BATS tests
-# Validates that each WASM HTTP leg returns valid JSON with expected shape.
+# Validates sources, build artifacts, and runtime legs.
 #
-# Prerequisites: all legs must already be built (make build) and running
-# on their designated ports.  These tests are run by benchmark.sh inline;
-# for standalone use start each leg manually first.
+# Naming: NNN_component — phase: description
+#
+# Build artifacts (in build/):
+#   hello-js-spin.wasm   — JS compiled via Spin              (legs 1a, 1b)
+#   hello-py-raw.wasm    — Python compiled via componentize-py (leg 2a)
+#   hello-py-spin.wasm   — Python compiled via Spin           (legs 2b, 2c)
+#   hello-rust.wasm      — Rust compiled via cargo            (leg 3)
+#   hello-as.wasm        — AssemblyScript via asc + wasm-tools (leg 4)
 
 SCRIPT_DIR="$(cd "$(dirname "$BATS_TEST_FILENAME")/.." && pwd)"
+GIT_ROOT="$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel)"
+PYTHON="uv run --directory $GIT_ROOT python"
+BUILD_DIR="$SCRIPT_DIR/build"
+
+# ── Helpers ───────────────────────────────────────────────────────────────────
 
-# ── Helper: fetch JSON from a running leg ─────────────────────────────────────
 json_get() {
   local port=$1 path=${2:-/}
   curl -sf "http://127.0.0.1:${port}${path}"
 }
 
-# ── Source validation helper ──────────────────────────────────────────────────
 valid_hello_json() {
   local json=$1
-  echo "$json" | python3 -c "
+  echo "$json" | $PYTHON -c "
 import sys, json
 d = json.load(sys.stdin)
 assert 'message' in d, 'missing message field'
@@ -28,90 +36,109 @@ print('ok')
 "
 }
 
-# ── Python source file smoke tests (no runtime required) ─────────────────────
-
-@test "python-spin/app.py is syntactically valid Python" {
-  python3 -m py_compile "$SCRIPT_DIR/python-spin/app.py"
-}
-
-@test "python-raw/app.py is syntactically valid Python" {
-  python3 -m py_compile "$SCRIPT_DIR/python-raw/app.py"
+skip_if_no_port() {
+  local port=$1
+  if ! curl -sf --max-time 1 "http://127.0.0.1:${port}/" >/dev/null 2>&1; then
+    skip "port ${port} not listening — start the leg first"
+  fi
 }
 
-# ── spin.toml presence ───────────────────────────────────────────────────────
+# ── js-spin ───────────────────────────────────────────────────────────────────
 
-@test "js-spin/spin.toml exists" {
+@test "001_js-spin — source: spin.toml exists" {
   [ -f "$SCRIPT_DIR/js-spin/spin.toml" ]
 }
 
-@test "python-spin/spin.toml exists" {
-  [ -f "$SCRIPT_DIR/python-spin/spin.toml" ]
+@test "002_js-spin — build: hello-js-spin.wasm exists" {
+  [ -f "$BUILD_DIR/hello-js-spin.wasm" ]
 }
 
-# ── WIT interface ─────────────────────────────────────────────────────────────
+@test "003_js-spin — leg 1a: native (port 5030) returns Hello World JSON" {
+  skip_if_no_port 5030
+  result=$(json_get 5030)
+  [ "$(valid_hello_json "$result")" = "ok" ]
+}
 
-@test "python-raw/wit/proxy.wit exists" {
-  [ -f "$SCRIPT_DIR/python-raw/wit/proxy.wit" ]
+@test "004_js-spin — leg 1b: podman (port 5031) returns Hello World JSON" {
+  skip_if_no_port 5031
+  result=$(json_get 5031)
+  [ "$(valid_hello_json "$result")" = "ok" ]
 }
 
-# ── AssemblyScript source ────────────────────────────────────────────────────
+# ── py-raw ────────────────────────────────────────────────────────────────────
 
-@test "as-hello/assembly/index.ts exists" {
-  [ -f "$SCRIPT_DIR/as-hello/assembly/index.ts" ]
+@test "005_py-raw — source: app.py is valid Python" {
+  $PYTHON -m py_compile "$SCRIPT_DIR/python-raw/app.py"
 }
 
-@test "as-hello/build.sh is executable" {
-  [ -x "$SCRIPT_DIR/as-hello/build.sh" ]
+@test "006_py-raw — source: wit/proxy.wit exists" {
+  [ -f "$SCRIPT_DIR/python-raw/wit/proxy.wit" ]
 }
 
-# ── Runtime leg tests (skipped when ports not listening) ─────────────────────
+@test "007_py-raw — build: hello-py-raw.wasm exists" {
+  [ -f "$BUILD_DIR/hello-py-raw.wasm" ]
+}
 
-@test "leg 1a JS/Spin native — returns Hello World JSON" {
-  skip_if_no_port 5030
-  result=$(json_get 5030)
+@test "008_py-raw — leg 2a: wasmtime (port 5032) returns Hello World JSON" {
+  skip_if_no_port 5032
+  result=$(json_get 5032)
   [ "$(valid_hello_json "$result")" = "ok" ]
 }
 
-@test "leg 1b JS/Spin podman — returns Hello World JSON" {
-  skip_if_no_port 5031
-  result=$(json_get 5031)
-  [ "$(valid_hello_json "$result")" = "ok" ]
+# ── py-spin ───────────────────────────────────────────────────────────────────
+
+@test "009_py-spin — source: app.py is valid Python" {
+  $PYTHON -m py_compile "$SCRIPT_DIR/python-spin/app.py"
 }
 
-@test "leg 2a Python/raw wasmtime — returns Hello World JSON" {
-  skip_if_no_port 5032
-  result=$(json_get 5032)
-  [ "$(valid_hello_json "$result")" = "ok" ]
+@test "010_py-spin — source: spin.toml exists" {
+  [ -f "$SCRIPT_DIR/python-spin/spin.toml" ]
 }
 
-@test "leg 2b Python/Spin native — returns Hello World JSON" {
+@test "011_py-spin — build: hello-py-spin.wasm exists" {
+  [ -f "$BUILD_DIR/hello-py-spin.wasm" ]
+}
+
+@test "012_py-spin — leg 2b: native (port 5033) returns Hello World JSON" {
   skip_if_no_port 5033
   result=$(json_get 5033)
   [ "$(valid_hello_json "$result")" = "ok" ]
 }
 
-@test "leg 2c Python/Spin podman — returns Hello World JSON" {
+@test "013_py-spin — leg 2c: podman (port 5034) returns Hello World JSON" {
   skip_if_no_port 5034
   result=$(json_get 5034)
   [ "$(valid_hello_json "$result")" = "ok" ]
 }
 
-@test "leg 3 Rust/wasmtime baseline — returns Hello World JSON" {
+# ── rust ──────────────────────────────────────────────────────────────────────
+
+@test "014_rust — build: hello-rust.wasm exists" {
+  [ -f "$BUILD_DIR/hello-rust.wasm" ]
+}
+
+@test "015_rust — leg 3: wasmtime (port 5035) returns Hello World JSON" {
   skip_if_no_port 5035
   result=$(json_get 5035)
   [ "$(valid_hello_json "$result")" = "ok" ]
 }
 
-@test "leg 4 AS/wasmtime — returns Hello World JSON" {
+# ── as-hello ──────────────────────────────────────────────────────────────────
+
+@test "016_as — source: assembly/index.ts exists" {
+  [ -f "$SCRIPT_DIR/as-hello/assembly/index.ts" ]
+}
+
+@test "017_as — source: build.sh is executable" {
+  [ -x "$SCRIPT_DIR/as-hello/build.sh" ]
+}
+
+@test "018_as — build: hello-as.wasm exists" {
+  [ -f "$BUILD_DIR/hello-as.wasm" ]
+}
+
+@test "019_as — leg 4: wasmtime (port 5036) returns Hello World JSON" {
   skip_if_no_port 5036
   result=$(json_get 5036)
   [ "$(valid_hello_json "$result")" = "ok" ]
 }
-
-# ── Helper loaded after test definitions ──────────────────────────────────────
-skip_if_no_port() {
-  local port=$1
-  if ! curl -sf --max-time 1 "http://127.0.0.1:${port}/" >/dev/null 2>&1; then
-    skip "port ${port} not listening — start the leg first"
-  fi
-}
diff --git a/experiments/001_hello_world/lib/bench.sh b/experiments/shared/lib/bench.sh
similarity index 100%
rename from experiments/001_hello_world/lib/bench.sh
rename to experiments/shared/lib/bench.sh