diff --git a/.gcp/Dockerfile.maintainer b/.gcp/Dockerfile.maintainer
new file mode 100644
index 0000000000..074df8441f
--- /dev/null
+++ b/.gcp/Dockerfile.maintainer
@@ -0,0 +1,52 @@
+# --- STAGE 1: Base Runtime ---
+FROM docker.io/library/node:20-slim AS base
+
+ARG CLI_VERSION_ARG
+ENV CLI_VERSION=$CLI_VERSION_ARG
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  python3 \
+  curl \
+  dnsutils \
+  less \
+  jq \
+  ca-certificates \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/*
+
+# --- STAGE 2: Maintainer ---
+FROM base AS maintainer
+
+# Install "Maintainer Bloat" - tools needed for development and offloading
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  make \
+  g++ \
+  gh \
+  git \
+  unzip \
+  rsync \
+  ripgrep \
+  procps \
+  psmisc \
+  lsof \
+  socat \
+  build-essential \
+  libsecret-1-dev \
+  libkrb5-dev \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/*
+
+# Install global dev tools
+RUN npm install -g tsx vitest
+
+# Set up npm global package folder
+RUN mkdir -p /usr/local/share/npm-global \
+  && chown -R node:node /usr/local/share/npm-global
+ENV NPM_CONFIG_PREFIX=/usr/local/share/npm-global
+ENV PATH=$PATH:/usr/local/share/npm-global/bin
+
+# Switch to non-root user node
+USER node
+
+# Default entrypoint
+CMD ["/bin/bash"]
diff --git a/.gcp/release-docker.yml b/.gcp/release-docker.yml
index cdf5a489a7..00780f7477 100644
--- a/.gcp/release-docker.yml
+++ b/.gcp/release-docker.yml
@@ -47,7 +47,7 @@ steps:
     env:
       - 'GEMINI_SANDBOX=$_CONTAINER_TOOL'
 
-  # Step 6: Build maintainer container image (Maintainer stage)
+  # Step 6: Build maintainer container image (Dedicated Maintainer Dockerfile)
   - name: 'us-west1-docker.pkg.dev/gemini-code-dev/gemini-code-containers/gemini-code-builder'
     id: 'Build maintainer Docker image'
     entrypoint: 'bash'
@@ -56,7 +56,7 @@ steps:
       - |-
         export TAG=$$(cat /workspace/image_tag.txt)
         IMAGE_BASE="us-docker.pkg.dev/gemini-code-dev/gemini-cli/maintainer"
-        docker build --target maintainer -t "$${IMAGE_BASE}:$${TAG}" .
+        docker build -f .gcp/Dockerfile.maintainer -t "$${IMAGE_BASE}:$${TAG}" .
         docker push "$${IMAGE_BASE}:$${TAG}"
     env:
       - 'GEMINI_SANDBOX=$_CONTAINER_TOOL'
diff --git a/Dockerfile b/Dockerfile
index b3a1edce40..25d27d46c6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,26 +1,21 @@
-# --- STAGE 1: Base Runtime ---
-FROM docker.io/library/node:20-slim AS base
+FROM docker.io/library/node:20-slim
 
+ARG SANDBOX_NAME="gemini-cli-sandbox"
 ARG CLI_VERSION_ARG
+ENV SANDBOX="$SANDBOX_NAME"
 ENV CLI_VERSION=$CLI_VERSION_ARG
 
+# install minimal set of packages, then clean up
 RUN apt-get update && apt-get install -y --no-install-recommends \
   python3 \
+  make \
+  g++ \
+  man-db \
   curl \
   dnsutils \
   less \
   jq \
-  ca-certificates \
-  && apt-get clean \
-  && rm -rf /var/lib/apt/lists/*
-
-# --- STAGE 2: Maintainer (Parent of Sandbox) ---
-FROM base AS maintainer
-
-# Install "Maintainer Bloat" - tools needed for development and offloading
-RUN apt-get update && apt-get install -y --no-install-recommends \
-  make \
-  g++ \
+  bc \
   gh \
   git \
   unzip \
@@ -30,31 +25,21 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   psmisc \
   lsof \
   socat \
-  build-essential \
-  libsecret-1-dev \
-  libkrb5-dev \
+  ca-certificates \
   && apt-get clean \
   && rm -rf /var/lib/apt/lists/*
 
-# Install global dev tools
-RUN npm install -g tsx vitest
-
-# Set up npm global package folder
+# set up npm global package folder under /usr/local/share
+# give it to non-root user node, already set up in base image
 RUN mkdir -p /usr/local/share/npm-global \
   && chown -R node:node /usr/local/share/npm-global
 ENV NPM_CONFIG_PREFIX=/usr/local/share/npm-global
 ENV PATH=$PATH:/usr/local/share/npm-global/bin
 
-# --- STAGE 3: Sandbox (Final CLI Image) ---
-FROM maintainer AS sandbox
-
-ARG SANDBOX_NAME="gemini-cli-sandbox"
-ENV SANDBOX="$SANDBOX_NAME"
-
-# Switch to non-root user node
+# switch to non-root user node
 USER node
 
-# Install gemini-cli and clean up
+# install gemini-cli and clean up
 COPY packages/cli/dist/google-gemini-cli-*.tgz /tmp/gemini-cli.tgz
 COPY packages/core/dist/google-gemini-cli-core-*.tgz /tmp/gemini-core.tgz
 RUN npm install -g /tmp/gemini-core.tgz \
@@ -64,5 +49,5 @@ RUN npm install -g /tmp/gemini-core.tgz \
   && npm cache clean --force \
   && rm -f /tmp/gemini-{cli,core}.tgz
 
-# Default entrypoint
+# default entrypoint when none specified
 CMD ["gemini"]