diff --git a/noir-projects/Earthfile b/noir-projects/Earthfile
index a73d56c7591..4345a432089 100644
--- a/noir-projects/Earthfile
+++ b/noir-projects/Earthfile
@@ -63,11 +63,10 @@ build-mock-protocol-circuits:
 
   ENV RAYON_NUM_THREADS=$RAYON_NUM_THREADS
   RUN echo "building with num threads $RAYON_NUM_THREADS"
-  RUN cd mock-protocol-circuits && BB_HASH=$bb_source_hash NARGO=nargo ./bootstrap.sh
+  RUN cd mock-protocol-circuits && BB_HASH=$bb_source_hash NARGO=nargo PARALLEL_VK=false ./bootstrap.sh
   SAVE ARTIFACT mock-protocol-circuits
 
 build:
-  ARG RAYON_NUM_THREADS
   FROM +source
   BUILD +build-contracts
   BUILD +build-protocol-circuits
diff --git a/noir-projects/mock-protocol-circuits/bootstrap.sh b/noir-projects/mock-protocol-circuits/bootstrap.sh
index 34926dcace8..d4c4ecd8cfd 100755
--- a/noir-projects/mock-protocol-circuits/bootstrap.sh
+++ b/noir-projects/mock-protocol-circuits/bootstrap.sh
@@ -22,9 +22,19 @@ BB_HASH=${BB_HASH:-$(cd ../../ && git ls-tree -r HEAD | grep 'barretenberg/cpp'
 echo Using BB hash $BB_HASH
 mkdir -p "./target/keys"
 
-for pathname in "./target"/*.json; do    
-    BB_HASH=$BB_HASH node ../scripts/generate_vk_json.js "$pathname" "./target/keys" &
-done
+PARALLEL_VK=${PARALLEL_VK:-true}
+
+if [[ $PARALLEL_VK == "true" ]]; then
+  echo "Generating vks in parallel..."
+  for pathname in "./target"/*.json; do
+      BB_HASH=$BB_HASH node ../scripts/generate_vk_json.js "$pathname" "./target/keys" &
+  done
+else
+  echo "Generating vks sequentially..."
+  for pathname in "./target"/*.json; do
+      BB_HASH=$BB_HASH node ../scripts/generate_vk_json.js "$pathname" "./target/keys"
+  done
+fi
 
 for job in $(jobs -p); do
   wait $job || exit 1
diff --git a/yarn-project/Earthfile b/yarn-project/Earthfile
index 363bd8e9dff..3accd2fee52 100644
--- a/yarn-project/Earthfile
+++ b/yarn-project/Earthfile
@@ -31,12 +31,11 @@ deps:
     RUN ln -s /usr/src/yarn-project/node_modules /usr/src/node_modules
 
 build:
-    ARG RAYON_NUM_THREADS
     # Prefetch targets to not wait for +deps.
     BUILD ../barretenberg/cpp/+build
     BUILD ../barretenberg/ts/+build
     BUILD ../noir/+nargo
-    BUILD ../noir-projects/+build
+    BUILD --pass-args ../noir-projects/+build
     BUILD ../l1-contracts/+build
     BUILD ../barretenberg/ts/+build
     BUILD ../noir/+packages
@@ -58,7 +57,6 @@ build-dev:
     SAVE ARTIFACT /usr/src /usr/src
 
 cli-base:
-    ARG RAYON_NUM_THREADS
     FROM +build
     # Remove a bunch of stuff that we don't need that takes up space.
     RUN rm -rf \
@@ -147,14 +145,12 @@ export-cli-wallet:
     SAVE IMAGE --push aztecprotocol/cli-wallet:${DIST_TAG}${ARCH:+-$ARCH}
 
 aztec-prod:
-    ARG RAYON_NUM_THREADS
     FROM +cli-base
     RUN yarn workspaces focus @aztec/aztec --production && yarn cache clean
     COPY --dir +rollup-verifier-contract/usr/src/bb /usr/src
     SAVE ARTIFACT /usr/src /usr/src
 
 aztec:
-    ARG RAYON_NUM_THREADS
     FROM ubuntu:noble
     RUN apt update && apt install nodejs curl jq -y && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
     COPY +aztec-prod/usr/src /usr/src
@@ -194,7 +190,6 @@ export-aztec-faucet:
 
 # We care about creating a slimmed down e2e image because we have to serialize it from earthly to docker for running.
 end-to-end-prod:
-    ARG RAYON_NUM_THREADS
     FROM +cli-base
     RUN yarn workspaces focus @aztec/end-to-end @aztec/cli-wallet --production && yarn cache clean
     COPY --dir +rollup-verifier-contract/usr/src/bb /usr/src
@@ -228,7 +223,6 @@ end-to-end-base:
     RUN ln -s /usr/src/yarn-project/.yarn/releases/yarn-3.6.3.cjs /usr/local/bin/yarn
 
 end-to-end:
-    ARG RAYON_NUM_THREADS
     FROM +end-to-end-base
 
     COPY +anvil/anvil /opt/foundry/bin/anvil
@@ -242,12 +236,10 @@ scripts-prod:
     SAVE ARTIFACT /usr/src /usr/src
 
 all:
-    ARG RAYON_NUM_THREADS
     BUILD +aztec
     BUILD +end-to-end
 
 export-aztec:
-    ARG RAYON_NUM_THREADS
     ARG EARTHLY_GIT_HASH
     FROM +aztec
     SAVE IMAGE aztecprotocol/aztec:$EARTHLY_GIT_HASH
@@ -264,7 +256,6 @@ export-end-to-end:
     SAVE IMAGE aztecprotocol/end-to-end:$EARTHLY_GIT_HASH
 
 export-e2e-test-images:
-    ARG RAYON_NUM_THREADS
     BUILD +export-aztec
     BUILD +export-end-to-end