diff --git a/.github/workflows/docker-ci.yml b/.github/workflows/docker-ci.yml
index 5124ebf..54285ea 100644
--- a/.github/workflows/docker-ci.yml
+++ b/.github/workflows/docker-ci.yml
@@ -30,57 +30,68 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  setup:
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.matrix.outputs.matrix }}
+      s6_version: ${{ steps.s6.outputs.version }}
+    steps:
+      - name: Compute build matrix
+        id: matrix
+        run: |
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            PHP_VERSIONS='["8.4","8.2"]'
+            echo "::notice::PR detected — testing PHP 8.4 + 8.2 only (skipping 8.3)"
+          else
+            PHP_VERSIONS='["8.4","8.3","8.2"]'
+          fi
+
+          # Build trixie include list for v2 based on selected PHP versions
+          INCLUDES="[]"
+          for ver in $(echo "$PHP_VERSIONS" | jq -r '.[]'); do
+            for type in fpm cli apache; do
+              INCLUDES=$(echo "$INCLUDES" | jq -c ". + [{\"variant\":\"v2\",\"php-version\":\"$ver\",\"php-type\":\"$type\",\"php-base\":\"trixie\"}]")
+            done
+          done
+
+          MATRIX=$(jq -n -c \
+            --argjson versions "$PHP_VERSIONS" \
+            --argjson includes "$INCLUDES" \
+            '{
+              "variant": ["v1","v2"],
+              "php-version": $versions,
+              "php-type": ["fpm","cli","apache"],
+              "php-base": ["alpine","bookworm"],
+              "exclude": [
+                {"php-type":"apache","php-base":"alpine"},
+                {"variant":"v2","php-base":"bookworm"}
+              ],
+              "include": $includes
+            }')
+
+          echo "matrix=$MATRIX" >> $GITHUB_OUTPUT
+
+      - name: Get latest s6-overlay version
+        id: s6
+        run: |
+          set -euo pipefail
+          RESPONSE="$(curl -fSLs \
+            -H "Authorization: Bearer ${{ github.token }}" \
+            https://api.github.com/repos/just-containers/s6-overlay/releases/latest)"
+          S6_OVERLAY_VERSION="$(echo "$RESPONSE" | jq -r .tag_name)"
+          if [ -z "$S6_OVERLAY_VERSION" ] || [ "$S6_OVERLAY_VERSION" = "null" ]; then
+            echo "::error::Failed to determine s6-overlay version"
+            exit 1
+          fi
+          echo "version=${S6_OVERLAY_VERSION}" >> $GITHUB_OUTPUT
+          echo "✅ Latest s6-overlay version: ${S6_OVERLAY_VERSION}"
+
   build-and-test:
+    needs: setup
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
-      matrix:
-        variant: [v1, v2]
-        php-version: ['8.4', '8.3', '8.2']
-        php-type: [fpm, cli, apache]
-        php-base: [alpine, bookworm]
-        exclude:
-          - php-type: apache
-            php-base: alpine
-          - variant: v2
-            php-base: bookworm
-        include:
-          - variant: v2
-            php-version: '8.4'
-            php-type: fpm
-            php-base: trixie
-          - variant: v2
-            php-version: '8.4'
-            php-type: cli
-            php-base: trixie
-          - variant: v2
-            php-version: '8.4'
-            php-type: apache
-            php-base: trixie
-          - variant: v2
-            php-version: '8.3'
-            php-type: fpm
-            php-base: trixie
-          - variant: v2
-            php-version: '8.3'
-            php-type: cli
-            php-base: trixie
-          - variant: v2
-            php-version: '8.3'
-            php-type: apache
-            php-base: trixie
-          - variant: v2
-            php-version: '8.2'
-            php-type: fpm
-            php-base: trixie
-          - variant: v2
-            php-version: '8.2'
-            php-type: cli
-            php-base: trixie
-          - variant: v2
-            php-version: '8.2'
-            php-type: apache
-            php-base: trixie
+      matrix: ${{ fromJson(needs.setup.outputs.matrix) }}
     
     name: ${{ matrix.variant }}-${{ matrix.php-version }}-${{ matrix.php-type }}-${{ matrix.php-base }}
     
@@ -88,18 +99,6 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Get latest s6-overlay version
-        id: s6-version
-        run: |
-          S6_OVERLAY_VERSION="$(curl -s https://api.github.com/repos/just-containers/s6-overlay/releases/latest | jq -r .tag_name)"
-          echo "version=${S6_OVERLAY_VERSION}" >> $GITHUB_OUTPUT
-          echo "✅ Latest s6-overlay version: ${S6_OVERLAY_VERSION}"
-
-      - name: Setup QEMU
-        uses: docker/setup-qemu-action@v3
-        with:
-          platforms: amd64,arm64,arm
-
       - name: Setup Docker Buildx
         uses: docker/setup-buildx-action@v3
 
@@ -138,7 +137,7 @@ jobs:
             VERSION=${{ steps.vars.outputs.VERSION }}
             PHPVERSION=${{ matrix.php-version }}
             BASEOS=${{ matrix.php-base }}
-            S6_OVERLAY_VERSION=${{ steps.s6-version.outputs.version }}
+            S6_OVERLAY_VERSION=${{ needs.setup.outputs.s6_version }}
             BUILD_DATE=${{ steps.vars.outputs.BUILD_DATE }}
             VCS_REF=${{ github.sha }}
           tags: test-${{ steps.vars.outputs.TAG }}
@@ -295,7 +294,7 @@ jobs:
           echo "::notice::✅ Build and tests passed for ${{ matrix.variant }} - ${{ steps.vars.outputs.TAG }}"
 
   publish:
-    needs: build-and-test
+    needs: [setup, build-and-test]
     if: github.ref == 'refs/heads/main' && (github.event_name == 'push' || github.event_name == 'schedule')
     runs-on: ubuntu-latest
     strategy:
@@ -356,13 +355,6 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Get latest s6-overlay version
-        id: s6-version
-        run: |
-          S6_OVERLAY_VERSION="$(curl -s https://api.github.com/repos/just-containers/s6-overlay/releases/latest | jq -r .tag_name)"
-          echo "version=${S6_OVERLAY_VERSION}" >> $GITHUB_OUTPUT
-          echo "✅ Latest s6-overlay version: ${S6_OVERLAY_VERSION}"
-
       - name: Setup QEMU
         uses: docker/setup-qemu-action@v3
         with:
@@ -429,7 +421,7 @@ jobs:
             VERSION=${{ steps.vars.outputs.VERSION }}
             PHPVERSION=${{ matrix.php-version }}
             BASEOS=${{ matrix.php-base }}
-            S6_OVERLAY_VERSION=${{ steps.s6-version.outputs.version }}
+            S6_OVERLAY_VERSION=${{ needs.setup.outputs.s6_version }}
             BUILD_DATE=${{ steps.vars.outputs.BUILD_DATE }}
             VCS_REF=${{ github.sha }}
           tags: |
diff --git a/Dockerfile.v1 b/Dockerfile.v1
index d980359..c1fa958 100644
--- a/Dockerfile.v1
+++ b/Dockerfile.v1
@@ -6,57 +6,29 @@ ARG BASEOS
 # Set environment variables
 ENV DEBIAN_FRONTEND=noninteractive
 
+COPY extras/retry.sh /usr/local/bin/retry
+RUN chmod +x /usr/local/bin/retry
+
 # Install dependencies based on the base OS
-RUN if [ "$BASEOS" = "bookworm" ]; then \
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked,id=apt-$BASEOS \
+    --mount=type=cache,target=/var/lib/apt/lists,sharing=locked,id=aptlists-$BASEOS \
+    if [ "$BASEOS" = "bookworm" ]; then \
         echo 'deb http://deb.debian.org/debian bookworm main' > /etc/apt/sources.list && \
         apt-get update && \
         apt-get -y upgrade && \
-        apt-get install -y --no-install-recommends curl git zip unzip ghostscript imagemagick optipng gifsicle pngcrush jpegoptim libjpeg-turbo-progs pngquant webp && \
-        rm -rf /var/lib/apt/lists/*; \
+        apt-get install -y --no-install-recommends curl git zip unzip ghostscript imagemagick optipng gifsicle pngcrush jpegoptim libjpeg-turbo-progs pngquant webp; \
     elif [ "$BASEOS" = "alpine" ]; then \
         apk update && \
         apk add --no-cache curl git zip unzip ghostscript imagemagick optipng gifsicle pngcrush jpegoptim libjpeg-turbo libjpeg-turbo-utils pngquant libwebp-tools; \
     fi
 
-# Add all needed PHP extensions with retry logic for transient network failures
-RUN for ATTEMPT in 1 2 3; do \
-        if curl -sSLf -o /usr/local/bin/install-php-extensions \
-            https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions; then \
-            break; \
-        else \
-            if [ $ATTEMPT -lt 3 ]; then \
-                case $ATTEMPT in \
-                    1) SLEEP_TIME=5 ;; \
-                    2) SLEEP_TIME=10 ;; \
-                esac; \
-                echo "Download attempt $ATTEMPT failed, retrying in ${SLEEP_TIME}s..."; \
-                sleep $SLEEP_TIME; \
-                rm -f /usr/local/bin/install-php-extensions; \
-            else \
-                echo "Failed to download install-php-extensions after 3 attempts"; \
-                exit 1; \
-            fi; \
-        fi; \
-    done && \
+# Download and install PHP extensions with retry for transient failures
+RUN retry 3 curl -sSLf -o /usr/local/bin/install-php-extensions \
+        https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions && \
     chmod +x /usr/local/bin/install-php-extensions && \
-    for ATTEMPT in 1 2 3; do \
-        if install-php-extensions amqp bcmath bz2 calendar ctype exif intl imagick imap json mbstring ldap mcrypt memcached mongodb \
-           mysqli opcache pdo_mysql pdo_pgsql pgsql redis snmp soap sockets tidy timezonedb uuid vips xsl yaml zip zstd @composer; then \
-            break; \
-        else \
-            if [ $ATTEMPT -lt 3 ]; then \
-                case $ATTEMPT in \
-                    1) SLEEP_TIME=5 ;; \
-                    2) SLEEP_TIME=10 ;; \
-                esac; \
-                echo "Extension installation attempt $ATTEMPT failed, retrying in ${SLEEP_TIME}s..."; \
-                sleep $SLEEP_TIME; \
-            else \
-                echo "Failed to install PHP extensions after 3 attempts"; \
-                exit 1; \
-            fi; \
-        fi; \
-    done
+    retry 3 install-php-extensions \
+        amqp bcmath bz2 calendar ctype exif intl imagick imap json mbstring ldap mcrypt memcached mongodb \
+        mysqli opcache pdo_mysql pdo_pgsql pgsql redis snmp soap sockets tidy timezonedb uuid vips xsl yaml zip zstd @composer
 
 # Enable Apache rewrite mod, if applicable
 RUN if command -v a2enmod; then a2enmod rewrite; fi
diff --git a/Dockerfile.v2 b/Dockerfile.v2
index 6c03b23..2d7fb79 100644
--- a/Dockerfile.v2
+++ b/Dockerfile.v2
@@ -12,6 +12,9 @@ ARG VERSION
 # Set environment variables
 ENV DEBIAN_FRONTEND=noninteractive
 
+COPY extras/retry.sh /usr/local/bin/retry
+RUN chmod +x /usr/local/bin/retry
+
 # OCI standard labels
 LABEL org.opencontainers.image.title="php-docker" \
       org.opencontainers.image.description="PHP runtime with s6-overlay and curated extensions" \
@@ -26,7 +29,9 @@ LABEL org.opencontainers.image.title="php-docker" \
 
 # Install build dependencies, PHP extensions, runtime libraries, and s6-overlay
 # Then clean up build-only packages in a single layer to minimize image size
-RUN if [ "$BASEOS" = "trixie" ] || [ "$BASEOS" = "bookworm" ]; then \
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked,id=apt-$BASEOS \
+    --mount=type=cache,target=/var/lib/apt/lists,sharing=locked,id=aptlists-$BASEOS \
+    if [ "$BASEOS" = "trixie" ] || [ "$BASEOS" = "bookworm" ]; then \
         apt-get update && \
         apt-get -y upgrade && \
         # Install build tools, dev packages, and runtime libraries together
@@ -129,25 +134,8 @@ RUN if [ "$BASEOS" = "trixie" ] || [ "$BASEOS" = "bookworm" ]; then \
             libxpm libxpm-dev; \
     fi && \
     # Download PHP extension installer with retry
-    for ATTEMPT in 1 2 3; do \
-        if curl -sSLf -o /usr/local/bin/install-php-extensions \
-            https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions; then \
-            break; \
-        else \
-            if [ $ATTEMPT -lt 3 ]; then \
-                case $ATTEMPT in \
-                    1) SLEEP_TIME=5 ;; \
-                    2) SLEEP_TIME=10 ;; \
-                esac; \
-                echo "Download attempt $ATTEMPT failed, retrying in ${SLEEP_TIME}s..."; \
-                sleep $SLEEP_TIME; \
-                rm -f /usr/local/bin/install-php-extensions; \
-            else \
-                echo "Failed to download install-php-extensions after 3 attempts"; \
-                exit 1; \
-            fi; \
-        fi; \
-    done && \
+    retry 3 curl -sSLf -o /usr/local/bin/install-php-extensions \
+        https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions && \
     chmod +x /usr/local/bin/install-php-extensions && \
     # Install PHP extensions
     install-php-extensions \
@@ -173,25 +161,10 @@ RUN if [ "$BASEOS" = "trixie" ] || [ "$BASEOS" = "bookworm" ]; then \
         *) S6_ARCH="x86_64" ;; \
     esac && \
     echo "Downloading s6-overlay ${S6_OVERLAY_VERSION} for ${S6_ARCH}" && \
-    for ATTEMPT in 1 2 3; do \
-        if wget -O /tmp/s6-overlay-noarch.tar.xz https://github.com/just-containers/s6-overlay/releases/download/${S6_OVERLAY_VERSION}/s6-overlay-noarch.tar.xz && \
-           wget -O /tmp/s6-overlay-${S6_ARCH}.tar.xz https://github.com/just-containers/s6-overlay/releases/download/${S6_OVERLAY_VERSION}/s6-overlay-${S6_ARCH}.tar.xz; then \
-            break; \
-        else \
-            if [ $ATTEMPT -lt 3 ]; then \
-                case $ATTEMPT in \
-                    1) SLEEP_TIME=5 ;; \
-                    2) SLEEP_TIME=10 ;; \
-                esac; \
-                echo "Download attempt $ATTEMPT failed, retrying in ${SLEEP_TIME}s..."; \
-                sleep $SLEEP_TIME; \
-                rm -f /tmp/s6-overlay-*.tar.xz; \
-            else \
-                echo "Failed to download s6-overlay after 3 attempts"; \
-                exit 1; \
-            fi; \
-        fi; \
-    done && \
+    retry 3 wget -O /tmp/s6-overlay-noarch.tar.xz \
+        https://github.com/just-containers/s6-overlay/releases/download/${S6_OVERLAY_VERSION}/s6-overlay-noarch.tar.xz && \
+    retry 3 wget -O /tmp/s6-overlay-${S6_ARCH}.tar.xz \
+        https://github.com/just-containers/s6-overlay/releases/download/${S6_OVERLAY_VERSION}/s6-overlay-${S6_ARCH}.tar.xz && \
     tar -C / -Jxpf /tmp/s6-overlay-noarch.tar.xz && \
     tar -C / -Jxpf /tmp/s6-overlay-${S6_ARCH}.tar.xz && \
     rm /tmp/s6-overlay-noarch.tar.xz /tmp/s6-overlay-${S6_ARCH}.tar.xz && \
diff --git a/extras/retry.sh b/extras/retry.sh
new file mode 100755
index 0000000..d6405f1
--- /dev/null
+++ b/extras/retry.sh
@@ -0,0 +1,21 @@
+#!/bin/sh
+# Retry a command with linear backoff
+# Usage: retry <max_attempts> <command...>
+# Example: retry 3 curl -sSLf -o /tmp/file https://example.com/file
+
+MAX=$1
+shift
+
+for ATTEMPT in $(seq 1 "$MAX"); do
+    if "$@"; then
+        exit 0
+    fi
+    if [ "$ATTEMPT" -lt "$MAX" ]; then
+        SLEEP_TIME=$((5 * ATTEMPT))
+        echo "Attempt $ATTEMPT/$MAX failed, retrying in ${SLEEP_TIME}s..."
+        sleep "$SLEEP_TIME"
+    fi
+done
+
+echo "Failed after $MAX attempts: $*"
+exit 1
diff --git a/extras/test-build.sh b/extras/test-build.sh
index 386be95..effab73 100755
--- a/extras/test-build.sh
+++ b/extras/test-build.sh
@@ -51,7 +51,7 @@ build_v1() {
     echo "Building v1: ${IMAGE_NAME}:${tag}"
     echo "  VERSION=${version}, PHPVERSION=${phpversion}, BASEOS=${baseos}"
     
-    docker build -f Dockerfile.v1 \
+    DOCKER_BUILDKIT=1 docker build -f Dockerfile.v1 \
         --build-arg VERSION="${version}" \
         --build-arg PHPVERSION="${phpversion}" \
         --build-arg BASEOS="${baseos}" \