diff --git a/.circleci/config.yml b/.circleci/config.yml
new file mode 100644
index 000000000..dc6a6623e
--- /dev/null
+++ b/.circleci/config.yml
@@ -0,0 +1,67 @@
+version: 2.1
+jobs:
+  lint-scripts:
+    docker:
+      - image: koalaman/shellcheck-alpine
+    steps:
+      - checkout
+      - run:
+          name: lint-scripts
+          command: .circleci/lint-scripts.sh
+
+  install-mysql:
+    docker:
+      - image: circleci/ruby:2.4.4
+      - image: circleci/mysql:5.7-ram
+        command: --max_allowed_packet=64MB
+        environment:
+          MYSQL_DATABASE: zammad_test
+          MYSQL_USER: zammad_test
+          MYSQL_PASSWORD: zammad_test
+    environment:
+      RAILS_ENV: test
+    steps:
+      - checkout
+      - run:
+          name: install-mysql
+          command: .circleci/install.sh
+
+  install-postgresql:
+    docker:
+      - image: circleci/ruby:2.4.4
+      - image: circleci/postgres:11-ram
+        environment:
+          POSTGRES_DB: zammad_test
+          POSTGRES_USER: zammad_test
+          POSTGRES_PASSWORD: zammad_test
+    environment:
+      RAILS_ENV: test
+    steps:
+      - checkout
+      - run:
+          name: install-postgresql
+          command: .circleci/install.sh
+
+  docker-image-build:
+    machine: true
+    steps:
+      - checkout
+      - run:
+          name: docker-image-build
+          command: .circleci/docker-image-build.sh
+
+workflows:
+  version: 2
+  install_unittest_dockerbuild:
+    jobs:
+      - lint-scripts
+      - install-mysql:
+          requires:
+            - lint-scripts
+      - install-postgresql:
+          requires:
+            - lint-scripts
+      - docker-image-build:
+          requires:
+            - install-mysql
+            - install-postgresql
diff --git a/.circleci/docker-image-build.sh b/.circleci/docker-image-build.sh
new file mode 100755
index 000000000..b744ad6ff
--- /dev/null
+++ b/.circleci/docker-image-build.sh
@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+#
+# build zammads docker & docker-compose images
+
+set -o errexit
+set -o pipefail
+
+REPO_ROOT="$(git rev-parse --show-toplevel)"
+REPO_USER="zammad"
+ZAMMAD_VERSION="$(git describe --tags | sed -e 's/-[a-z0-9]\{8,\}.*//g')"
+export ZAMMAD_VERSION
+
+if [ "${CIRCLE_BRANCH}" == 'develop' ]; then
+  DOCKER_REPOSITORY="zammad-docker"
+  BUILD_SCRIPT="scripts/build_image.sh"
+elif [ "${CIRCLE_BRANCH}" == 'stable' ]; then
+  DOCKER_REPOSITORY="zammad-docker-compose"
+  BUILD_SCRIPT="hooks/build.sh"
+else
+  echo "branch is ${CIRCLE_BRANCH}... no docker image build needed..."
+  exit 0
+fi
+
+# dockerhub auth
+echo "${DOCKER_PASSWORD}" | docker login --username="${DOCKER_USERNAME}" --password-stdin
+
+# clone docker repo
+git clone https://github.com/"${REPO_USER}"/"${DOCKER_REPOSITORY}"
+
+# enter dockerfile dir
+cd "${REPO_ROOT}/${DOCKER_REPOSITORY}"
+
+# build & push docker image
+# shellcheck disable=SC1090
+source "${REPO_ROOT}/${DOCKER_REPOSITORY}/${BUILD_SCRIPT}"
diff --git a/.circleci/install.sh b/.circleci/install.sh
new file mode 100755
index 000000000..4eccd04e4
--- /dev/null
+++ b/.circleci/install.sh
@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+#
+# install & unit test zammad
+#
+
+set -o errexit
+set -o pipefail
+
+DB_CONFIG="test:\n  adapter: postgresql\n  database: zammad_test\n  host: 127.0.0.1\n  pool: 50\n  timeout: 5000\n  encoding: utf8\n  username: zammad_test\n  password: zammad_test"
+
+# install build dependencies
+sudo apt-get update
+sudo apt-get install -y --no-install-recommends autoconf automake autotools-dev bison build-essential curl git-core libffi-dev libgdbm-dev libgmp-dev libmariadbclient-dev-compat libncurses5-dev libreadline-dev libsqlite3-dev libssl-dev libtool libxml2-dev libxslt1-dev libyaml-0-2 libyaml-dev patch pkg-config postfix sqlite3 zlib1g-dev
+
+if [ "${CIRCLE_JOB}" == "install-mysql" ]; then
+  DB_ADAPTER="mysql2"
+  INSTALL_OPTION="postgres"
+elif [ "${CIRCLE_JOB}" == "install-postgresql" ]; then
+  DB_ADAPTER="postgresql"
+  INSTALL_OPTION="mysql"
+else
+  echo "nothing to do for circle ci job ${CIRCLE_JOB}..."
+  exit 0
+fi
+
+# create db config
+echo -e "${DB_CONFIG}" | sed "s/adapter: postgresql/adapter: ${DB_ADAPTER}/g" > config/database.yml
+
+# install zammad
+bundle install --without "${INSTALL_OPTION}"
+
+# unit tests
+bundle exec rubocop
+rake db:migrate
+rake db:seed
+bundle exec rspec -t ~type:system
+bundle exec rake db:environment:set RAILS_ENV=test
+rake db:reset
+rake test:units
+ruby -I test/ test/integration/object_manager_test.rb
+ruby -I test/ test/integration/package_test.rb
diff --git a/.circleci/lint-scripts.sh b/.circleci/lint-scripts.sh
new file mode 100755
index 000000000..da44ac63e
--- /dev/null
+++ b/.circleci/lint-scripts.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+#
+# lint bash scripts
+#
+
+set -o errexit
+
+CONFIG_DIR="./.circleci"
+TMP_FILE="$(mktemp)"
+
+find "${CONFIG_DIR}" -type f -name "*.sh" > "${TMP_FILE}"
+
+while read -r FILE; do
+  echo lint "${FILE}"
+  shellcheck -x "${FILE}"
+done < "${TMP_FILE}"
+
+rm "${TMP_FILE}"
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index d4adaadc4..000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,70 +0,0 @@
-dist: xenial
-sudo: false
-notifications:
-  email:
-    - me+tv@zammad.com
-env:
-  - DB=mysql
-  - DB=postgresql
-addons:
-  apt:
-    packages:
-      - autoconf
-      - automake
-      - autotools-dev
-      - bison
-      - build-essential
-      - curl
-      - git-core
-      - libffi-dev
-      - libgdbm-dev
-      - libgmp-dev
-      - libmysqlclient-dev
-      - libncurses5-dev
-      - libreadline-dev
-      - libsqlite3-dev
-      - libssl-dev
-      - libtool
-      - libxml2-dev
-      - libxslt1-dev
-      - libyaml-0-2
-      - libyaml-dev
-      - patch
-      - pkg-config
-      - postfix
-      - sqlite3
-      - zlib1g-dev
-services:
-  - mysql
-  - postgresql
-language: ruby
-rvm:
-  - 2.4.4
-before_install:
-  - gem update --system # Due to: https://github.com/travis-ci/travis-ci/issues/8978
-  - git fetch --unshallow
-  - if [ "${DB}" = "mysql" ]; then mysql -u root -e "CREATE USER 'some_user'@'localhost' IDENTIFIED BY 'some_pass';"; fi
-  - if [ "${DB}" = "mysql" ]; then mysql -u root -e "GRANT ALL PRIVILEGES ON *.* TO 'some_user'@'localhost';"; fi
-  - if [ "${DB}" = "mysql" ]; then cp contrib/travis-ci.org/database.yml.test-mysql config/database.yml; fi
-  - if [ "${DB}" = "postgresql" ]; then psql -c 'create database zammad_test;' -U postgres; fi
-  - if [ "${DB}" = "postgresql" ]; then cp contrib/travis-ci.org/database.yml.test-postgresql config/database.yml; fi
-  - export RAILS_ENV=test
-  - export ZAMMAD_VERSION=$(git describe --tags | sed -e 's/-[a-z0-9]\{8,\}.*//g')
-install:
-  - if [ "${DB}" = "mysql" ]; then bundle install --without postgres; fi
-  - if [ "${DB}" = "postgresql" ]; then bundle install; fi
-script:
-  - bundle exec rubocop
-  - rake db:create
-  - rake db:migrate
-  - rake db:seed
-  - bundle exec rspec -t ~type:system
-  - bundle exec rake db:environment:set RAILS_ENV=test
-  - rake db:reset
-  - rake test:units
-  - ruby -I test/ test/integration/object_manager_test.rb
-  - ruby -I test/ test/integration/package_test.rb
-after_success:
-  - if [ "${DB}" = "mysql" ]; then contrib/travis-ci.org/trigger_docker_image_build.sh; fi
-  - if [ "${DB}" = "mysql" ]; then contrib/travis-ci.org/trigger_docker_image_compose_build.sh; fi
-  - if [ "${DB}" = "mysql" ]; then contrib/travis-ci.org/trigger_docker_image_univention_build.sh; fi
diff --git a/README.md b/README.md
index ae977c35e..9871f97d9 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 Zammad is a web based open source helpdesk/customer support system with many
 features to manage customer communication via several channels like telephone,
-facebook, twitter, chat and e-mails. It is distributed under version 3 of the 
+facebook, twitter, chat and e-mails. It is distributed under version 3 of the
 GNU AFFERO General Public License (GNU AGPLv3).
 
 Do you receive many e-mails and want to answer them with a team of agents?
@@ -11,7 +11,7 @@ You're going to love Zammad!
 
 ## Status
 
-- Build: [![Build Status](https://travis-ci.org/zammad/zammad.svg?branch=develop)](https://travis-ci.org/zammad/zammad)
+- Build: [![Build Status](https://circleci.com/gh/zammad/zammad.svg?style=svg)](https://circleci.com/gh/zammad/zammad)
 - Code: [![Code Climate](https://codeclimate.com/github/zammad/zammad/badges/gpa.svg)](https://codeclimate.com/github/zammad/zammad) [![Coverage Status](https://coveralls.io/repos/github/zammad/zammad/badge.svg)](https://coveralls.io/github/zammad/zammad)
 - Docs: [![Documentation Status](https://readthedocs.org/projects/zammad/badge/)](https://docs.zammad.org)
 - Issues: [![Percentage of issues still open](http://isitmaintained.com/badge/open/zammad/zammad.svg)](https://github.com/zammad/zammad/issues "Percentage of issues still open") [![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/zammad/zammad.svg)](https://github.com/zammad/zammad/issues?q=is%3Aissue+is%3Aclosed "Average time to resolve an issue")
@@ -44,4 +44,3 @@ https://zammad.org/participate
 Thanks! ❤️ ❤️ ❤️
 
  Your Zammad Team
-
diff --git a/contrib/travis-ci.org/database.yml.test-mysql b/contrib/travis-ci.org/database.yml.test-mysql
deleted file mode 100644
index f6b525b4c..000000000
--- a/contrib/travis-ci.org/database.yml.test-mysql
+++ /dev/null
@@ -1,11 +0,0 @@
-# Warning: The database defined as "test" will be erased and
-# re-generated from your development database when you run "rake".
-# Do not set this db to the same as development or production.
-test:
-  adapter: mysql2
-  database: zammad_test
-  pool: 50
-  timeout: 5000
-  encoding: utf8
-  username: some_user
-  password: some_pass
diff --git a/contrib/travis-ci.org/database.yml.test-postgresql b/contrib/travis-ci.org/database.yml.test-postgresql
deleted file mode 100644
index bda094235..000000000
--- a/contrib/travis-ci.org/database.yml.test-postgresql
+++ /dev/null
@@ -1,11 +0,0 @@
-# Warning: The database defined as "test" will be erased and
-# re-generated from your development database when you run "rake".
-# Do not set this db to the same as development or production.
-test:
-  adapter: postgresql
-  database: zammad_test
-  pool: 50
-  timeout: 5000
-  encoding: utf8
-  username: postgres
-  password:
diff --git a/contrib/travis-ci.org/trigger_docker_image_build.sh b/contrib/travis-ci.org/trigger_docker_image_build.sh
deleted file mode 100755
index f27972919..000000000
--- a/contrib/travis-ci.org/trigger_docker_image_build.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-#
-# trigger build of https://github.com/zammad/zammad-docker on https://travis-ci.org/zammad/zammad-docker and upload it to https://hub.docker.com/r/zammad/zammad
-#
-
-REPO_USER="zammad"
-REPO="zammad-docker"
-BRANCH="master"
-
-if [ "${TRAVIS_BRANCH}" == 'develop' ]; then
-  curl -X POST \
-    -H "Content-Type: application/json" \
-    -H "Travis-API-Version: 3" \
-    -H "Accept: application/json" \
-    -H "Authorization: token ${TRAVIS_API_TOKEN}" \
-    -d '{"request":{ "message": "'"${TRAVIS_COMMIT_MESSAGE}"'","branch":"'${BRANCH}'","config":{"env":{"ZAMMAD_VERSION":"'${ZAMMAD_VERSION}'"}}}}' \
-    "https://api.travis-ci.org/repo/${REPO_USER}%2F${REPO}/requests"
-fi
diff --git a/contrib/travis-ci.org/trigger_docker_image_compose_build.sh b/contrib/travis-ci.org/trigger_docker_image_compose_build.sh
deleted file mode 100755
index 2b209d5be..000000000
--- a/contrib/travis-ci.org/trigger_docker_image_compose_build.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-#
-# trigger build of https://github.com/zammad/zammad-docker-compose on https://travis-ci.org/zammad/zammad-docker-compose and upload it to https://hub.docker.com/r/zammad/zammad-docker-compose/
-#
-
-REPO_USER="zammad"
-REPO="zammad-docker-compose"
-BRANCH="master"
-
-if [ "${TRAVIS_BRANCH}" == 'stable' ]; then
-  curl -X POST \
-    -H "Content-Type: application/json" \
-    -H "Travis-API-Version: 3" \
-    -H "Accept: application/json" \
-    -H "Authorization: token ${TRAVIS_API_TOKEN}" \
-    -d '{"request":{ "message": "'"${TRAVIS_COMMIT_MESSAGE}"'","branch":"'${BRANCH}'","config":{"env":{"ZAMMAD_VERSION":"'${ZAMMAD_VERSION}'"}}}}' \
-    "https://api.travis-ci.org/repo/${REPO_USER}%2F${REPO}/requests"
-fi
diff --git a/contrib/travis-ci.org/trigger_docker_image_univention_build.sh b/contrib/travis-ci.org/trigger_docker_image_univention_build.sh
deleted file mode 100755
index 0e83bc280..000000000
--- a/contrib/travis-ci.org/trigger_docker_image_univention_build.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-#
-# trigger build of https://github.com/zammad/zammad-docker-univention on https://travis-ci.org/zammad/zammad-docker-univention and upload it to https://hub.docker.com/r/zammad/zammad-docker-univention
-#
-
-REPO_USER="zammad"
-REPO="zammad-docker-univention"
-BRANCH="master"
-
-if [ "${TRAVIS_BRANCH}" == 'stable' ]; then
-  curl -X POST \
-    -H "Content-Type: application/json" \
-    -H "Travis-API-Version: 3" \
-    -H "Accept: application/json" \
-    -H "Authorization: token ${TRAVIS_API_TOKEN}" \
-    -d '{"request":{ "message": "'"${TRAVIS_COMMIT_MESSAGE}"'","branch":"'${BRANCH}'","config":{"env":{"ZAMMAD_VERSION":"'${ZAMMAD_VERSION}'"}}}}' \
-    "https://api.travis-ci.org/repo/${REPO_USER}%2F${REPO}/requests"
-fi