diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 386986f..fe32a3a 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -20,9 +20,11 @@ variables:
   rules:
     - if: '$CI_COMMIT_BRANCH == "master"'
     - if: '$CI_COMMIT_BRANCH == "next"'
+    # TODO: Remove this after debugging
+    - if: '$CI_COMMIT_BRANCH == "multiarch-docker-support"'
     - if: '$CI_COMMIT_TAG'
   interruptible: true
-  image: "rust:latest"
+  image: "rust:1.56.0"
   tags: ["docker"]
   cache:
     paths:
@@ -30,16 +32,16 @@ variables:
       - target/
     key: "build_cache-$TARGET-release"
   variables:
-    CARGO_PROFILE_RELEASE_LTO=true
-    CARGO_PROFILE_RELEASE_CODEGEN_UNITS=1
+    CARGO_PROFILE_RELEASE_LTO: "off" # TODO: change to true again
+    CARGO_PROFILE_RELEASE_CODEGEN_UNITS: "256" # TODO: Change to 1 again
+    RUSTUP_HOME: "/root/.rustup"
   before_script:
+    - echo $USER
+    - export PATH="root/.cargo/bin:$PATH"
     - 'echo "Building for target $TARGET"'
     - 'mkdir -p cargohome && CARGOHOME="cargohome"'
     - "cat /etc/*-release && rustc --version && cargo --version"  # Print version info for debugging
-    - 'apt-get update -yqq'
-    - 'echo "Installing packages: $NEEDED_PACKAGES"'
-    - "apt-get install -yqq --no-install-recommends $NEEDED_PACKAGES"
-    - "rustup target add $TARGET"
+    - 'time rustup target add "$TARGET"'
   script:
     - time cargo build --target $TARGET --release
     - 'mv "target/$TARGET/release/conduit" "conduit-$TARGET"'
@@ -57,52 +59,64 @@ build:release:cargo:x86_64-unknown-linux-gnu:
       - "conduit-x86_64-unknown-linux-gnu"
     expose_as: "Conduit for x86_64-unknown-linux-gnu"
 
+build:release:cargo:x86_64-unknown-linux-musl:
+  image: registry.gitlab.fachschaften.org/jfowl/cargo-cross-for-ci/cargo-cross-builder:rust1.56.0-x86_64-unknown-linux-musl
+  extends: .build-cargo-shared-settings
+  variables:
+    TARGET: "x86_64-unknown-linux-musl"
+  artifacts:
+    name: "conduit-x86_64-unknown-linux-musl"
+    paths:
+      - "conduit-x86_64-unknown-linux-musl"
+    expose_as: "Conduit for x86_64-unknown-linux-musl"
+
+
 build:release:cargo:armv7-unknown-linux-gnueabihf:
   extends: .build-cargo-shared-settings
+  image:
+    name: registry.gitlab.fachschaften.org/jfowl/cargo-cross-for-ci/cargo-cross-builder:rust1.56.0-armv7-unknown-linux-gnueabihf
   variables:
     TARGET: "armv7-unknown-linux-gnueabihf"
-    NEEDED_PACKAGES: "build-essential gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf libc6-dev-armhf-cross"
-    CARGO_TARGET_ARMV7_UNKNOWN_LINUX_GNUEABIHF_LINKER: arm-linux-gnueabihf-gcc
-    CC_armv7_unknown_linux_gnueabihf: arm-linux-gnueabihf-gcc
-    CXX_armv7_unknown_linux_gnueabihf: arm-linux-gnueabihf-g++
   artifacts:
     name: "conduit-armv7-unknown-linux-gnueabihf"
     paths:
       - "conduit-armv7-unknown-linux-gnueabihf"
     expose_as: "Conduit for armv7-unknown-linux-gnueabihf"
 
+build:release:cargo:armv7-unknown-linux-musleabihf:
+  extends: .build-cargo-shared-settings
+  image:
+    name: registry.gitlab.fachschaften.org/jfowl/cargo-cross-for-ci/cargo-cross-builder:rust1.56.0-armv7-unknown-linux-musleabihf
+  variables:
+    TARGET: "armv7-unknown-linux-musleabihf"
+  artifacts:
+    name: "conduit-armv7-unknown-linux-musleabihf"
+    paths:
+      - "conduit-armv7-unknown-linux-musleabihf"
+    expose_as: "Conduit for armv7-unknown-linux-musleabihf"
+
+
 build:release:cargo:aarch64-unknown-linux-gnu:
+  image: registry.gitlab.fachschaften.org/jfowl/cargo-cross-for-ci/cargo-cross-builder:rust1.56.0-aarch64-unknown-linux-gnu
   extends: .build-cargo-shared-settings
   variables:
     TARGET: "aarch64-unknown-linux-gnu"
-    NEEDED_PACKAGES: "build-essential gcc-10-aarch64-linux-gnu g++-aarch64-linux-gnu libc6-dev-arm64-cross"
-    CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER: aarch64-linux-gnu-gcc
-    CC_aarch64_unknown_linux_gnu: aarch64-linux-gnu-gcc
-    CXX_aarch64_unknown_linux_gnu: aarch64-linux-gnu-g++
-    TARGET_CC: "/usr/bin/aarch64-linux-gnu-gcc-10"
-    TARGET_AR: "/usr/bin/aarch64-linux-gnu-gcc-ar-10"
   artifacts:
     name: "conduit-aarch64-unknown-linux-gnu"
     paths:
       - "conduit-aarch64-unknown-linux-gnu"
     expose_as: "Conduit for aarch64-unknown-linux-gnu"
 
-build:release:cargo:x86_64-unknown-linux-musl:
+build:release:cargo:aarch64-unknown-linux-musl:
+  image: registry.gitlab.fachschaften.org/jfowl/cargo-cross-for-ci/cargo-cross-builder:rust1.56.0-aarch64-unknown-linux-musl
   extends: .build-cargo-shared-settings
-  image: "rust:alpine"
   variables:
-    TARGET: "x86_64-unknown-linux-musl"
-  before_script:
-    - 'echo "Building for target $TARGET"'
-    - 'mkdir -p cargohome && CARGOHOME="cargohome"'
-    - "cat /etc/*-release && rustc --version && cargo --version"  # Print version info for debugging
-    - "rustup target add $TARGET"
-    - "apk add libc-dev"
+    TARGET: "aarch64-unknown-linux-musl"
   artifacts:
-    name: "conduit-x86_64-unknown-linux-musl"
+    name: "conduit-aarch64-unknown-linux-musl"
     paths:
-      - "conduit-x86_64-unknown-linux-musl"
-    expose_as: "Conduit for x86_64-unknown-linux-musl"
+      - "conduit-aarch64-unknown-linux-musl"
+    expose_as: "Conduit for aarch64-unknown-linux-musl"
 
 
 
@@ -213,7 +227,6 @@ build:cargo-deb:x86_64-unknown-linux-gnu:
     - "mkdir -p /kaniko/.docker"
     - 'echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"},\"$DOCKER_HUB\":{\"username\":\"$DOCKER_HUB_USER\",\"password\":\"$DOCKER_HUB_PASSWORD\"}}}" > /kaniko/.docker/config.json'
 
-
 build:docker:next:
   extends: .docker-shared-settings
   needs:
@@ -280,6 +293,40 @@ build:docker:tags:
     - if: '$CI_COMMIT_TAG'
 
 
+build:docker:new-way-of-building:
+  stage: "build docker image"
+  image: jdrouet/docker-with-buildx:stable
+  tags: ["docker"]
+  services:
+  - docker:dind
+  needs:
+    - "build:release:cargo:x86_64-unknown-linux-musl"
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "master"'
+    - if: '$CI_COMMIT_BRANCH == "next"'
+    # TODO: Remove this after debugging
+    - if: '$CI_COMMIT_BRANCH == "multiarch-docker-support"'
+  variables:
+    DOCKER_HOST: tcp://docker:2375/
+    DOCKER_TLS_CERTDIR: ""
+    DOCKER_DRIVER: overlay2
+    # PLATFORMS: "linux/arm/v7,linux/arm64/v8,linux/amd64"
+    PLATFORMS: "linux/amd64"
+    IMAGE_TAG: "$CI_REGISTRY_IMAGE/debug-conduit:multiarch-test-dont-use-yet"
+    DOCKER_FILE: "docker/ci-binaries-packaging.Dockerfile"
+  before_script:
+    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
+  script:
+    # Prepare buildx to build multiarch stuff:
+    - docker context create 'ci-context'
+    - docker buildx create --name 'multiarch-builder' --use 'ci-context'
+    # Copy binaries to their docker arch path
+    - mkdir -p linux/ && mv ./conduit-x86_64-unknown-linux-musl linux/amd64
+    # Actually build multiarch image:
+    - docker buildx build --push --platform $PLATFORMS --tag $IMAGE_TAG --file $DOCKER_FILE .
+
+
+
 
 # --------------------------------------------------------------------- #
 #  Run tests                                                            #
diff --git a/Dockerfile b/Dockerfile
index f4b176f..56a8059 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,97 +1,52 @@
-# Using multistage build:
-# 	https://docs.docker.com/develop/develop-images/multistage-build/
-# 	https://whitfin.io/speeding-up-rust-docker-builds/
-
-
-##########################  BUILD IMAGE  ##########################
-# Alpine build image to build Conduit's statically compiled binary
-FROM alpine:3.14 as builder
-
-# Install packages needed for building all crates
-RUN apk add --no-cache \
-        cargo \
-        openssl-dev
-
-# Specifies if the local project is build or if Conduit gets build
-# from the official git repository. Defaults to the git repo.
-ARG LOCAL=false
-# Specifies which revision/commit is build. Defaults to HEAD
-ARG GIT_REF=origin/master
-
-# Copy project files from current folder
-COPY . .
-# Build it from the copied local files or from the official git repository
-RUN if [[ $LOCAL == "true" ]]; then \
-        mv ./docker/healthcheck.sh . ; \
-        echo "Building from local source..." ; \
-        cargo install --path . ; \
-    else \
-        echo "Building revision '${GIT_REF}' from online source..." ; \
-        cargo install --git "https://gitlab.com/famedly/conduit.git" --rev ${GIT_REF} ; \
-        echo "Loadings healthcheck script from online source..." ; \
-        wget "https://gitlab.com/famedly/conduit/-/raw/${GIT_REF#origin/}/docker/healthcheck.sh" ; \
-    fi
-
-########################## RUNTIME IMAGE ##########################
-# Create new stage with a minimal image for the actual
-# runtime image/container
+# syntax=docker/dockerfile:1
+FROM rust:1.53-alpine as builder
+WORKDIR /usr/src/conduit
+
+# == Build dependencies without our own code separately for caching ==
+#
+# Need a fake main.rs since Cargo refuses to build anything otherwise.
+#
+# See https://github.com/rust-lang/cargo/issues/2644 for a Cargo feature
+# request that would allow just dependencies to be compiled, presumably
+# regardless of whether source files are available.
+RUN mkdir src && echo 'fn main() {}' > src/main.rs
+COPY Cargo.toml Cargo.lock ./
+RUN cargo build
+# TODO: RUN cargo build --release
+
+# == Actual build ==
+RUN rm -r src
+COPY src src
+# main.rs has to have its timestamp updated for this to work correctly since
+# otherwise the build with the fake main.rs from above is newer than the
+# source files (COPY preserves timestamps).
+RUN touch src/main.rs
+
+RUN cargo install --path .
+# TODO: RUN cargo install --release --path . 
+
+
+# This build stage is going to be run later
 FROM alpine:3.14
 
-ARG CREATED
-ARG VERSION
-ARG GIT_REF=origin/master
-
-ENV CONDUIT_CONFIG="/srv/conduit/conduit.toml"
-
-# Labels according to https://github.com/opencontainers/image-spec/blob/master/annotations.md
-# including a custom label specifying the build command
-LABEL org.opencontainers.image.created=${CREATED} \
-      org.opencontainers.image.authors="Conduit Contributors" \
-      org.opencontainers.image.title="Conduit" \
-      org.opencontainers.image.version=${VERSION} \
-      org.opencontainers.image.vendor="Conduit Contributors" \
-      org.opencontainers.image.description="A Matrix homeserver written in Rust" \
-      org.opencontainers.image.url="https://conduit.rs/" \
-      org.opencontainers.image.revision=${GIT_REF} \
-      org.opencontainers.image.source="https://gitlab.com/famedly/conduit.git" \
-      org.opencontainers.image.licenses="Apache-2.0" \
-      org.opencontainers.image.documentation="" \
-      org.opencontainers.image.ref.name="" \
-      org.label-schema.docker.build="docker build . -t matrixconduit/matrix-conduit:latest --build-arg CREATED=$(date -u +'%Y-%m-%dT%H:%M:%SZ') --build-arg VERSION=$(grep -m1 -o '[0-9].[0-9].[0-9]' Cargo.toml)" \
-      maintainer="Weasy666"
-
-# Standard port on which Conduit launches. You still need to map the port when using the docker command or docker-compose.
-EXPOSE 6167
-
-# Copy config files from context and the binary from
-# the "builder" stage to the current stage into folder
-# /srv/conduit and create data folder for database
-RUN mkdir -p /srv/conduit/.local/share/conduit
-COPY --from=builder /root/.cargo/bin/conduit /srv/conduit/
-COPY --from=builder ./healthcheck.sh /srv/conduit/
-
-# Add www-data user and group with UID 82, as used by alpine
-# https://git.alpinelinux.org/aports/tree/main/nginx/nginx.pre-install
-RUN set -x ; \
-    addgroup -Sg 82 www-data 2>/dev/null ; \
-    adduser -S -D -H -h /srv/conduit -G www-data -g www-data www-data 2>/dev/null ; \
-    addgroup www-data www-data 2>/dev/null && exit 0 ; exit 1
-
-# Change ownership of Conduit files to www-data user and group
-RUN chown -cR www-data:www-data /srv/conduit
-
 # Install packages needed to run Conduit
 RUN apk add --no-cache \
         ca-certificates \
         curl \
         libgcc
 
-# Test if Conduit is still alive, uses the same endpoint as Element
-HEALTHCHECK --start-period=5s --interval=60s CMD ./healthcheck.sh
+# Prepare path for database and media files
+RUN mkdir -p /srv/conduit/.local/share/conduit
+
+# TODO: Change ? or maybe leave it like that
+RUN mkdir -p /srv/conduit/.local/share/conduit
+COPY --from=builder /usr/local/cargo/bin/conduit /srv/conduit/
+
+# TODO: Check if we don't want to just use ENVs for running condit in docker
+ENV CONDUIT_CONFIG="/srv/conduit/conduit.toml"
+
+# TODO: not needed, but documents it?
+EXPOSE 6167
 
-# Set user to www-data
-USER www-data
-# Set container home directory
 WORKDIR /srv/conduit
-# Run Conduit
-ENTRYPOINT [ "/srv/conduit/conduit" ]
+ENTRYPOINT [ "/srv/conduit/conduit" ]
\ No newline at end of file
diff --git a/docker/ci-binaries-packaging.Dockerfile b/docker/ci-binaries-packaging.Dockerfile
index fb67439..f1bbdfa 100644
--- a/docker/ci-binaries-packaging.Dockerfile
+++ b/docker/ci-binaries-packaging.Dockerfile
@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 # ---------------------------------------------------------------------------------------------------------
 # This Dockerfile is intended to be built as part of Conduit's CI pipeline.
 # It does not build Conduit in Docker, but just copies the matching build artifact from the build job.
@@ -33,7 +34,7 @@ LABEL org.opencontainers.image.created=${CREATED} \
       org.opencontainers.image.revision=${GIT_REF} \
       org.opencontainers.image.source="https://gitlab.com/famedly/conduit.git" \
       org.opencontainers.image.licenses="Apache-2.0" \
-      org.opencontainers.image.documentation="" \
+      org.opencontainers.image.documentation="https://gitlab.com/famedly/conduit" \
       org.opencontainers.image.ref.name=""
 
 # Standard port on which Conduit launches. You still need to map the port when using the docker command or docker-compose.
@@ -42,9 +43,16 @@ EXPOSE 6167
 # create data folder for database
 RUN mkdir -p /srv/conduit/.local/share/conduit
 
-# Copy the Conduit binary into the image at the latest possible moment to maximise caching:
-COPY ./conduit-x86_64-unknown-linux-musl /srv/conduit/conduit
+# Test if Conduit is still alive, uses the same endpoint as Element
 COPY ./docker/healthcheck.sh /srv/conduit/
+HEALTHCHECK --start-period=5s --interval=60s CMD ./healthcheck.sh
+
+# Copy the Conduit binary into the image at the latest possible moment to maximise caching:
+
+# depending on the target platform (e.g. "linux/arm/v7", "linux/arm64/v8", or "linux/amd64")
+# copy the matching binary into this docker image
+ARG TARGETPLATFORM
+COPY ./$TARGETPLATFORM /srv/conduit/conduit
 
 # Add www-data user and group with UID 82, as used by alpine
 # https://git.alpinelinux.org/aports/tree/main/nginx/nginx.pre-install
@@ -57,10 +65,6 @@ RUN set -x ; \
 RUN chown -cR www-data:www-data /srv/conduit
 RUN chmod +x /srv/conduit/healthcheck.sh
 
-
-# Test if Conduit is still alive, uses the same endpoint as Element
-HEALTHCHECK --start-period=5s --interval=60s CMD ./healthcheck.sh
-
 # Set user to www-data
 USER www-data
 # Set container home directory