diff --git a/Dockerfile.dropshell-build b/Dockerfile.dropshell-build
new file mode 100644
index 0000000..f6fa58c
--- /dev/null
+++ b/Dockerfile.dropshell-build
@@ -0,0 +1,74 @@
+ARG IMAGE_TAG
+FROM gitea.jde.nz/public/dropshell-build-base:latest AS builder
+
+ARG PROJECT
+ARG CMAKE_BUILD_TYPE=Debug
+
+# Set working directory
+WORKDIR /app
+
+SHELL ["/bin/bash", "-c"]
+
+# Create cache directories
+RUN mkdir -p /ccache
+
+# Set up ccache
+ENV CCACHE_DIR=/ccache
+ENV CCACHE_COMPILERCHECK=content
+ENV CCACHE_MAXSIZE=2G
+
+# Copy only build files first (for better layer caching)
+#COPY CMakeLists.txt cmake_prebuild.sh ./
+#COPY src/version.hpp.in src/
+
+# Run prebuild script early (this rarely changes)
+#RUN bash cmake_prebuild.sh
+
+# Copy source files (this invalidates cache when source changes)
+COPY src/ src/
+COPY CMakeLists.txt ./
+
+# Configure project (this step is cached unless CMakeLists.txt changes)
+RUN --mount=type=cache,target=/ccache \
+    --mount=type=cache,target=/build \
+    mkdir -p /build && \
+    cmake -G Ninja -S /app -B /build \
+    -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} \
+    -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
+    -DCMAKE_C_COMPILER_LAUNCHER=ccache \
+    -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=mold -static -g" \
+    -DCMAKE_CXX_FLAGS="-g -fno-omit-frame-pointer" \
+    -DCMAKE_C_FLAGS="-g -fno-omit-frame-pointer" \
+    -DPROJECT_NAME="${PROJECT}" \
+    -DCMAKE_STRIP=OFF \
+    ${CMAKE_TOOLCHAIN_FILE:+-DCMAKE_TOOLCHAIN_FILE=$CMAKE_TOOLCHAIN_FILE}
+
+# Build project (ccache will help here when only some files change)
+RUN --mount=type=cache,target=/ccache \
+    --mount=type=cache,target=/build \
+    cmake --build /build
+
+# Copy the built executable to a regular directory for the final stage
+RUN --mount=type=cache,target=/build \
+    mkdir -p /output && \
+    if [ -f "/build/${PROJECT}" ]; then \
+        echo "Found executable at /build/${PROJECT}" && \
+        cp "/build/${PROJECT}" "/output/${PROJECT}"; \
+    else \
+        echo "Executable not found at /build/${PROJECT}, searching..." && \
+        find /build -type f -executable -name "*${PROJECT}*" -exec cp {} /output/${PROJECT} \; || \
+        find /build -type f -executable -exec cp {} /output/${PROJECT} \; || \
+        (echo "Error: Could not find executable for ${PROJECT}" && ls -la /build && exit 1); \
+    fi
+
+# if we're a release build, then run upx on the binary.
+RUN if [ "${CMAKE_BUILD_TYPE}" = "Release" ]; then \
+        upx /output/${PROJECT}; \
+    fi
+
+# Final stage that only contains the binary
+FROM scratch AS project
+ARG PROJECT
+# Copy the actual binary from the regular directory
+COPY --from=builder /output/${PROJECT} /${PROJECT}
+
diff --git a/build.sh b/build.sh
index fcbb00c..4974f36 100755
--- a/build.sh
+++ b/build.sh
@@ -1,52 +1,30 @@
 #!/bin/bash
+
 set -euo pipefail
 
-# Get script directory - handle different execution contexts
 SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
 PROJECT="$(basename "${SCRIPT_DIR}")"
 
-# Debug output for CI
-echo "${PROJECT} build script running from: ${SCRIPT_DIR}"
+export CMAKE_BUILD_TYPE="Debug"
 
-# handle running locally, or docker in docker via gitea runner.
-if [ -n "${GITEA_CONTAINER_NAME:-}" ]; then
-  echo "We're in a gitea container: ${GITEA_CONTAINER_NAME}"
-  VOLUME_OPTS=("--volumes-from=${GITEA_CONTAINER_NAME}")
-  WORKING_DIR=("-w" "${GITHUB_WORKSPACE}/${PROJECT}")
-  BUILD_DIR="${GITHUB_WORKSPACE}/${PROJECT}/build"
-  OUTPUT_DIR="${GITHUB_WORKSPACE}/${PROJECT}/output"
-else
-  VOLUME_OPTS=("-v" "${SCRIPT_DIR}:/app")
-  WORKING_DIR=("-w" "/app")
-  BUILD_DIR="${SCRIPT_DIR}/build"
-  OUTPUT_DIR="${SCRIPT_DIR}/output"
+rm -rf "${SCRIPT_DIR}/output" 
+mkdir -p "${SCRIPT_DIR}/output"
+
+# make sure we have the latest base image.
+docker pull gitea.jde.nz/public/dropshell-build-base:latest
+
+# Build with or without cache based on NO_CACHE environment variable
+CACHE_FLAG=""
+if [ "${NO_CACHE:-false}" = "true" ]; then
+    CACHE_FLAG="--no-cache"
 fi
 
-# Create output directory
-mkdir -p "${OUTPUT_DIR}"
+docker build \
+  ${CACHE_FLAG} \
+  -t "${PROJECT}-build" \
+  -f "${SCRIPT_DIR}/Dockerfile.dropshell-build" \
+  --build-arg PROJECT="${PROJECT}" \
+  --build-arg CMAKE_BUILD_TYPE="${CMAKE_BUILD_TYPE}" \
+  --output "${SCRIPT_DIR}/output" \
+  "${SCRIPT_DIR}"
 
-# Run build in container with mounted directories
-COMMAND_TO_RUN="cmake -G Ninja -S . -B ./build \
-                -DCMAKE_BUILD_TYPE=\${CMAKE_BUILD_TYPE} \
-                -DPROJECT_NAME=${PROJECT} && \
-                cmake --build ./build" 
-
-echo "Building in new docker container"
-docker run --rm \
-  --user "$(id -u):$(id -g)" \
-  "${VOLUME_OPTS[@]}" \
-  "${WORKING_DIR[@]}" \
-  -e CMAKE_BUILD_TYPE="${CMAKE_BUILD_TYPE:-Debug}" \
-  gitea.jde.nz/public/dropshell-build-base:latest \
-  bash -c "${COMMAND_TO_RUN}"
-
-# Copy built executable to output directory
-if [ -f "${BUILD_DIR}/${PROJECT}" ]; then
-  cp "${BUILD_DIR}/${PROJECT}" "${OUTPUT_DIR}/"
-  echo "✓ Build successful - ${PROJECT} copied to ${OUTPUT_DIR}/"
-else
-  echo "✗ Build failed - ${PROJECT} not found in ${BUILD_DIR}/"
-  exit 1
-fi
-
-echo "Build complete"
diff --git a/contrib/xxhash.hpp b/src/xxhash.hpp
similarity index 100%
rename from contrib/xxhash.hpp
rename to src/xxhash.hpp