diff --git a/node-chrome-packagejson/Dockerfile b/node-chrome-packagejson/Dockerfile
index 70adfcb..896cb10 100644
--- a/node-chrome-packagejson/Dockerfile
+++ b/node-chrome-packagejson/Dockerfile
@@ -4,10 +4,17 @@
 # 3) Observe that the button's value is printed.
 # ---------------------------------------------------------------------------------------------
 
-# 1) Use alpine-based NodeJS base image
+# 1) Restore npm packages in a separate layer
+FROM node:latest as build
+WORKDIR /home/node
+COPY package.json .
+RUN npm config set unsafe-perm true
+RUN npm i
+
+# 2) Build the final image
 FROM node:latest
 
-# 2) Install latest stable Chrome
+# 3) Install latest stable Chrome
 # https://gerg.dev/2021/06/making-chromedriver-and-chrome-versions-match-in-a-docker-image/
 RUN echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" | \
     tee -a /etc/apt/sources.list.d/google.list && \
@@ -16,27 +23,23 @@ RUN echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" |
     apt-get update && \
     apt-get install -y google-chrome-stable libxss1
 
-# 3) Install the Chromedriver version that corresponds to the installed major Chrome version
+# 4) Install the Chromedriver version that corresponds to the installed major Chrome version
 # https://blogs.sap.com/2020/12/01/ui5-testing-how-to-handle-chromedriver-update-in-docker-image/
-RUN google-chrome --version | grep -oE "[0-9]{1,10}.[0-9]{1,10}.[0-9]{1,10}" > /tmp/chromebrowser-main-version.txt
-RUN wget --no-verbose -O /tmp/latest_chromedriver_version.txt https://chromedriver.storage.googleapis.com/LATEST_RELEASE_$(cat /tmp/chromebrowser-main-version.txt)
-RUN wget --no-verbose -O /tmp/chromedriver_linux64.zip https://chromedriver.storage.googleapis.com/$(cat /tmp/latest_chromedriver_version.txt)/chromedriver_linux64.zip && rm -rf /opt/selenium/chromedriver && unzip /tmp/chromedriver_linux64.zip -d /opt/selenium && rm /tmp/chromedriver_linux64.zip && mv /opt/selenium/chromedriver /opt/selenium/chromedriver-$(cat /tmp/latest_chromedriver_version.txt) && chmod 755 /opt/selenium/chromedriver-$(cat /tmp/latest_chromedriver_version.txt) && ln -fs /opt/selenium/chromedriver-$(cat /tmp/latest_chromedriver_version.txt) /usr/bin/chromedriver
+RUN google-chrome --version | grep -oE "[0-9]{1,10}.[0-9]{1,10}.[0-9]{1,10}" > /tmp/chromebrowser-main-version.txt && \
+    wget --no-verbose -O /tmp/latest_chromedriver_version.txt https://chromedriver.storage.googleapis.com/LATEST_RELEASE_$(cat /tmp/chromebrowser-main-version.txt) && \
+    wget --no-verbose -O /tmp/chromedriver_linux64.zip https://chromedriver.storage.googleapis.com/$(cat /tmp/latest_chromedriver_version.txt)/chromedriver_linux64.zip && rm -rf /opt/selenium/chromedriver && unzip /tmp/chromedriver_linux64.zip -d /opt/selenium && rm /tmp/chromedriver_linux64.zip && mv /opt/selenium/chromedriver /opt/selenium/chromedriver-$(cat /tmp/latest_chromedriver_version.txt) && chmod 755 /opt/selenium/chromedriver-$(cat /tmp/latest_chromedriver_version.txt) && ln -fs /opt/selenium/chromedriver-$(cat /tmp/latest_chromedriver_version.txt) /usr/bin/chromedriver
 
 # 4) Set the variable for the container working directory, create and set the working directory
 ARG WORK_DIRECTORY=/program
-RUN mkdir -p $WORK_DIRECTORY
-WORKDIR $WORK_DIRECTORY
-
-# 5) Install npm packages (do this AFTER setting the working directory)
-COPY package.json .
-RUN npm config set unsafe-perm true
-RUN npm i
 ENV NODE_ENV=development NODE_PATH=$WORK_DIRECTORY
+# Working directory will be created if it doesn't exist (no explicit 'mkdir' needed)
+WORKDIR $WORK_DIRECTORY 
+COPY --from=build /home/node/* ./
 
-# 6) Copy script to execute to working directory
-COPY runtest.js .
+# 6) expose a volume for mounting the tests
+VOLUME ${WORK_DIRECTORY}/app
 
 EXPOSE 8080
 
 # 7) Execute the script in NodeJS
-CMD ["node", "runtest.js"]
\ No newline at end of file
+CMD ["node", "app/runtest.js"]
\ No newline at end of file
diff --git a/node-chrome-packagejson/example.sh b/node-chrome-packagejson/example.sh
new file mode 100644
index 0000000..c1a02e1
--- /dev/null
+++ b/node-chrome-packagejson/example.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+# build the image
+docker build -t packagejson .
+# run the image, binding the current directory to the container
+docker run --rm -it --mount type=bind,source="$(pwd)",target=/program/app packagejson
\ No newline at end of file