diff --git a/Dockerfile b/Dockerfile
index d205450..290954c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,26 +1,35 @@
-FROM php:7.4
-
-# Install npm
-# libzip-dev: for the PHP zip extension (used by Composer)
-RUN curl -sL https://deb.nodesource.com/setup_12.x | bash - \
-    && apt update && apt install -y git ssh apache2-utils nodejs python3-pip libzip-dev zip && rm -rf /var/lib/apt/lists/*
-
-# Install Composer
-RUN curl -sS https://getcomposer.org/installer | php \
-    && mv composer.phar /usr/local/bin/composer \
-    && chmod +x /usr/local/bin/composer
-
-# Install the `aws` CLI tool
-RUN pip3 install --upgrade --user awscli && echo 'export PATH=/root/.local/bin:$PATH'>/root/.bashrc
-
-# Install serverless
-RUN npm install -g serverless
-
-RUN docker-php-ext-install zip pdo_mysql
-
-RUN mkdir -p /var/task
-
-# Register the Serverless and AWS bin directories
-ENV PATH="/root/.serverless/bin:/root/.local/bin:${PATH}"
-
-WORKDIR '/var/task'
+FROM composer:latest
+
+# composer
+#   https://github.com/composer/docker/blob/master/1.10/Dockerfile
+#   based on php:7-alpine
+#     https://github.com/docker-library/php/blob/master/7.4/alpine3.11/cli/Dockerfile
+#     based on alpine:3.11
+
+# Package Dependencies:
+#   serverless
+#     docker
+#   awscli
+#     groff: needed by the AWS cli
+#   hirak/prestissimo: accelerates installing Composer dependencies
+#   yarn: npm alternative
+RUN adduser -D -G users -h /home/app app \
+    && composer global require hirak/prestissimo \
+    && apk add --no-cache \
+        docker \
+        yarn \
+        groff \
+    && yarn global add serverless \
+    && pip3 install \
+        --progress-bar off \
+        --no-cache-dir \
+        --disable-pip-version-check \
+        awscli
+
+USER app
+ENV PATH=$PATH:/tmp/vendor/bin \
+    COMPOSER_HOME=/var/task/.composer
+VOLUME /var/task
+VOLUME /home/app/.aws
+VOLUME /var/run/docker.sock
+WORKDIR /var/task
diff --git a/README.md b/README.md
index 4a662f1..d23e464 100644
--- a/README.md
+++ b/README.md
@@ -1,14 +1,22 @@
-This repository provides a development environment for Bref via a Docker image.
+This repository provides a development environment for Bref via single Docker image and convenience script.
 
 Thanks to that image you can easily get started with Bref without having to install its tools: `serverless`, `aws`, `php`, `composer`…
 
 ## Usage
 
-Run any command in the container:
+Run any command in the container using `./dev-env`:
 
 ```bash
-docker run --rm -it bref/dev-env <command>
+./dev-env <command>
 
 # For example:
-docker run --rm -it bref/dev-env php -v
+./dev-env php -v
 ```
+
+You can also clone this repo and make a symlink of `dev-env` script to somewhere in your `$PATH`.
+
+## Explanations
+
+Bref is NOT preinstalled in `bref/dev-env` image. For it to work you have to first install it via `./dev-env composer require bref/bref`. This will create not only typical `vendor` directory in your project but also `.composer` directory for Composer cache, which you can add to your `.gitignore` file.
+
+The Serverless util uses `.serverless` directory also located in your project. You can ignore that as well.
diff --git a/dev-env b/dev-env
new file mode 100755
index 0000000..f423ec5
--- /dev/null
+++ b/dev-env
@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+
+set -eu
+
+# This is an array of where the Docker socket usually is on most distributions
+declare -a POSSIBLE_DOCKER_SOCK_PATHS=(
+    /run/docker.sock
+    /var/run/docker.sock
+)
+
+# Path to your `docker.sock` file is required for `serverless invoke local --docker -f myFunction` to work.
+DOCKER_SOCK_PATH=
+readonly DOCKER_GROUP_ID=$(getent group docker | cut -d: -f3)
+readonly AWS_CONF_DIR="${HOME}/.aws"
+
+# Find out which of the possible paths for Docker socket is valid
+for path in "${POSSIBLE_DOCKER_SOCK_PATHS[@]}" ; do
+    if [[ -S "${path}" ]]; then
+        DOCKER_SOCK_PATH="${path}"
+        break
+    fi
+done
+
+if [[ -z "${DOCKER_SOCK_PATH}" ]]; then
+    echo "Unable to locate Docker socket."
+    echo "Please make sure Docker service is installed."
+    exit 1
+fi
+
+if [[ ! -d "${AWS_CONF_DIR}" ]]; then
+    echo "AWS settings directory is not found in ${AWS_CONF_DIR}"
+    exit 1
+fi
+
+# --user So that all files created in container are actually owned by the user running this container
+# --group-add Sets GID of a user able to run Docker since docker commands run in container
+#   will still be run via Docker socket so user running this container needs to be able to work with it
+# The `HOST_AWS_CONF_DIR` ENV variable is needed for running `bref/dashboard`.
+#   It's because we can't simply use volume mappings from inside of `bref/dev-env` container
+#   since in case of Docker in Docker mappings are from host instead.
+docker run --rm --interactive --tty \
+    --user "$(id -u)":"$(id -g)" \
+    --group-add "${DOCKER_GROUP_ID}" \
+    --env HOST_AWS_CONF_DIR="${AWS_CONF_DIR}" \
+    --volume "${DOCKER_SOCK_PATH}:/var/run/docker.sock" \
+    --volume "${AWS_CONF_DIR}:/home/app/.aws" \
+    --volume "${PWD}:/app" \
+    "bref/dev-env" "$@"