diff --git a/.travis.yml b/.travis.yml
index c60961c9..86579a33 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,18 +4,24 @@ dist: trusty
 
 branches:
   only:
-  - master
+    - master
 
 language: go
 
 go:
   - 1.11.6
 
+env:
+  - KUBECONFIG=${HOME}/.kube/config PATH=$HOME/k8scli:$HOME/tool:$HOME/google-cloud-sdk/bin:${PATH} GO111MODULE=on DOCKER_CACHE_DIR=${HOME}/docker/
+
 cache:
   directories:
     - $HOME/google-cloud-sdk/
     - $HOME/k8scli
     - $HOME/tool
+    - $HOME/docker
+    - $HOME/.cache/go-build
+    - $HOME/gopath/pkg/mod
 
 services:
   - docker
@@ -29,24 +35,27 @@ before_install:
 install:
   - hack/travis-kube-setup.sh
 
-env:
-  - KUBECONFIG=${HOME}/.kube/config PATH=$HOME/k8scli:$HOME/tool:$HOME/google-cloud-sdk/bin:${PATH} GO111MODULE=on
-
 before_script:
   - cd ${TRAVIS_BUILD_DIR}
   - go mod download
-  - go mod vendor
   - hack/verify-staticcheck.sh
   - hack/verify-gofmt.sh
   - hack/verify-govet.sh
   - helm lint charts/fission-all/ charts/fission-core/
   - hack/runtests.sh
+  - test/build.sh
 
 script:
   - cd ${TRAVIS_BUILD_DIR}
-  - test/build_and_test.sh
+  - test/test.sh
   - test/upgrade/fission_upgrade_test.sh
 
+before_cache:
+  - test/save_cache.sh # save docker cache
+
+after_script:
+  - kubectl --namespace default delete configmap -l travisID=${TRAVIS_BUILD_ID} # remove in-test configmap to indicate this CI build finished
+
 notifications:
   slack:
     rooms:
diff --git a/cmd/builder/Dockerfile.fission-builder b/cmd/builder/Dockerfile.fission-builder
index f532dc4d..fb9afc4c 100644
--- a/cmd/builder/Dockerfile.fission-builder
+++ b/cmd/builder/Dockerfile.fission-builder
@@ -4,15 +4,6 @@ RUN apk add --update ca-certificates
 FROM golang:1.11-alpine as fission-builder
 RUN apk add bash ca-certificates git gcc g++ libc-dev
 
-ARG GITCOMMIT=unknown
-# E.g. GITCOMMIT=$(git rev-parse HEAD)
-
-ARG BUILDVERSION=unknown
-# E.g. BUILDVERSION=$(git rev-parse HEAD)
-
-ARG BUILDDATE=unknown
-# E.g. BUILDDATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
-
 ARG GOPKG=github.com/fission/fission
 
 ENV GO111MODULE=on
@@ -29,6 +20,15 @@ COPY ./ ./
 
 WORKDIR /go/src/${GOPKG}/cmd/builder
 
+ARG GITCOMMIT=unknown
+# E.g. GITCOMMIT=$(git rev-parse HEAD)
+
+ARG BUILDVERSION=unknown
+# E.g. BUILDVERSION=$(git rev-parse HEAD)
+
+ARG BUILDDATE=unknown
+# E.g. BUILDDATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \
     -o /go/bin/builder \
     -gcflags=-trimpath=$GOPATH \
diff --git a/cmd/fetcher/Dockerfile.fission-fetcher b/cmd/fetcher/Dockerfile.fission-fetcher
index 8915b7cb..d1e62967 100644
--- a/cmd/fetcher/Dockerfile.fission-fetcher
+++ b/cmd/fetcher/Dockerfile.fission-fetcher
@@ -4,15 +4,6 @@ RUN apk add --update ca-certificates
 FROM golang:1.11-alpine as builder
 RUN apk add bash ca-certificates git gcc g++ libc-dev
 
-ARG GITCOMMIT=unknown
-# E.g. GITCOMMIT=$(git rev-parse HEAD)
-
-ARG BUILDVERSION=unknown
-# E.g. BUILDVERSION=$(git rev-parse HEAD)
-
-ARG BUILDDATE=unknown
-# E.g. BUILDDATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
-
 ARG GOPKG=github.com/fission/fission
 
 ENV GO111MODULE=on
@@ -29,6 +20,15 @@ COPY ./ ./
 
 WORKDIR /go/src/${GOPKG}/cmd/fetcher
 
+ARG GITCOMMIT=unknown
+# E.g. GITCOMMIT=$(git rev-parse HEAD)
+
+ARG BUILDVERSION=unknown
+# E.g. BUILDVERSION=$(git rev-parse HEAD)
+
+ARG BUILDDATE=unknown
+# E.g. BUILDDATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \
     -o /go/bin/fetcher \
     -gcflags=-trimpath=$GOPATH \
diff --git a/cmd/fission-bundle/Dockerfile.fission-bundle b/cmd/fission-bundle/Dockerfile.fission-bundle
index 0e283855..ab928a94 100644
--- a/cmd/fission-bundle/Dockerfile.fission-bundle
+++ b/cmd/fission-bundle/Dockerfile.fission-bundle
@@ -4,15 +4,6 @@ RUN apk add --update ca-certificates
 FROM golang:1.11-alpine as builder
 RUN apk add bash ca-certificates git gcc g++ libc-dev
 
-ARG GITCOMMIT=unknown
-# E.g. GITCOMMIT=$(git rev-parse HEAD)
-
-ARG BUILDVERSION=unknown
-# E.g. BUILDVERSION=$(git rev-parse HEAD)
-
-ARG BUILDDATE=unknown
-# E.g. BUILDDATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
-
 ARG GOPKG=github.com/fission/fission
 
 ENV GO111MODULE=on
@@ -29,6 +20,15 @@ COPY ./ ./
 
 WORKDIR /go/src/${GOPKG}/cmd/fission-bundle
 
+ARG GITCOMMIT=unknown
+# E.g. GITCOMMIT=$(git rev-parse HEAD)
+
+ARG BUILDVERSION=unknown
+# E.g. BUILDVERSION=$(git rev-parse HEAD)
+
+ARG BUILDDATE=unknown
+# E.g. BUILDDATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \
     -o /go/bin/fission-bundle \
     -gcflags=-trimpath=$GOPATH \
diff --git a/cmd/preupgradechecks/Dockerfile.fission-preupgradechecks b/cmd/preupgradechecks/Dockerfile.fission-preupgradechecks
index 4990aec4..b8e9f91e 100644
--- a/cmd/preupgradechecks/Dockerfile.fission-preupgradechecks
+++ b/cmd/preupgradechecks/Dockerfile.fission-preupgradechecks
@@ -4,15 +4,6 @@ RUN apk add --update ca-certificates
 FROM golang:1.11-alpine as builder
 RUN apk add bash ca-certificates git gcc g++ libc-dev
 
-ARG GITCOMMIT=unknown
-# E.g. GITCOMMIT=$(git rev-parse HEAD)
-
-ARG BUILDVERSION=unknown
-# E.g. BUILDVERSION=$(git rev-parse HEAD)
-
-ARG BUILDDATE=unknown
-# E.g. BUILDDATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
-
 ARG GOPKG=github.com/fission/fission
 
 ENV GO111MODULE=on
@@ -29,6 +20,15 @@ COPY ./ ./
 
 WORKDIR /go/src/${GOPKG}/cmd/preupgradechecks
 
+ARG GITCOMMIT=unknown
+# E.g. GITCOMMIT=$(git rev-parse HEAD)
+
+ARG BUILDVERSION=unknown
+# E.g. BUILDVERSION=$(git rev-parse HEAD)
+
+ARG BUILDDATE=unknown
+# E.g. BUILDDATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \
     -o /go/bin/pre-upgrade-checks \
     -gcflags=-trimpath=$GOPATH \
diff --git a/environments/python/Dockerfile b/environments/python/Dockerfile
index f4fac883..83370821 100644
--- a/environments/python/Dockerfile
+++ b/environments/python/Dockerfile
@@ -1,14 +1,15 @@
 FROM alpine:3.5
 
-RUN apk update
-RUN apk add --no-cache python3 python3-dev build-base libev-dev
-RUN pip3 install --upgrade pip
-RUN rm -r /root/.cache
+WORKDIR /app
+
+RUN apk add --no-cache python3 python3-dev build-base libev-dev && \
+    pip3 install --upgrade pip && \
+    rm -r /root/.cache
+
+COPY requirements.txt /app
+RUN pip3 install -r requirements.txt
 
 COPY . /app
-WORKDIR /app
-RUN pip3 install -r requirements.txt
 
 ENTRYPOINT ["python3"]
 CMD ["server.py"]
-
diff --git a/environments/python/Dockerfile-2.7 b/environments/python/Dockerfile-2.7
index 87e6455f..ceb60420 100644
--- a/environments/python/Dockerfile-2.7
+++ b/environments/python/Dockerfile-2.7
@@ -1,14 +1,15 @@
 FROM alpine:3.5
 
-RUN apk update
-RUN apk add --no-cache python python-dev build-base py-pip libev-dev
-RUN pip install --upgrade pip
-RUN rm -r /root/.cache
+WORKDIR /app
+
+RUN apk add --no-cache python python-dev build-base py-pip libev-dev && \
+    pip install --upgrade pip && \
+    rm -r /root/.cache
+
+COPY requirements.txt /app
+RUN pip install -r requirements.txt
 
 COPY . /app
-WORKDIR /app
-RUN pip install -r requirements.txt
 
 ENTRYPOINT ["python"]
 CMD ["server.py"]
-
diff --git a/environments/tensorflow-serving/Dockerfile b/environments/tensorflow-serving/Dockerfile
index ade52016..7fdb210f 100644
--- a/environments/tensorflow-serving/Dockerfile
+++ b/environments/tensorflow-serving/Dockerfile
@@ -10,7 +10,7 @@ ENV APP	   ${GOPATH}/src/github.com/fission/fission/environments/tensorflow-serv
 
 WORKDIR ${APP}
 
-ADD server.go   ${APP}
+ADD server.go ${APP}
 
 RUN go get
 RUN go build -a -o /server server.go
diff --git a/hack/release.sh b/hack/release.sh
index 9b6224be..4a1f0acb 100755
--- a/hack/release.sh
+++ b/hack/release.sh
@@ -329,8 +329,6 @@ fi
 
 release_environment_check $version $chartsrepo
 
-go mod vendor
-
 # Build release-builder image
 docker build -t fission-release-builder -f $GOPATH/src/github.com/fission/fission/hack/Dockerfile .
 
diff --git a/skaffold.yaml b/skaffold.yaml
index 8926b022..101b26a6 100644
--- a/skaffold.yaml
+++ b/skaffold.yaml
@@ -5,7 +5,6 @@
 ############## Usage ##############
 # Skaffold CLI should be installed on your machine. 
 # Change <DOCKERHUB_REPO> -> to your Dockerhub username
-# Run `go mod vendor` so that all dependencies are downloaded
 # Run `skaffold run` to build and deploy with helm. 
 # Run`skaffold build` to only build and push images
 ############## Current Limitations ##############
diff --git a/test/build_and_test.sh b/test/build.sh
similarity index 72%
rename from test/build_and_test.sh
rename to test/build.sh
index 7b6f5ebe..66e03cea 100755
--- a/test/build_and_test.sh
+++ b/test/build.sh
@@ -17,18 +17,19 @@ fi
 
 source $(dirname $0)/test_utils.sh
 
-REPO=gcr.io/fission-ci
-IMAGE=fission-bundle
-FETCHER_IMAGE=$REPO/fetcher
-BUILDER_IMAGE=$REPO/builder
-TAG=test
-PRUNE_INTERVAL=1 # this variable controls the interval to run archivePruner. The unit is in minutes.
-ROUTER_SERVICE_TYPE=LoadBalancer
-SERVICE_TYPE=LoadBalancer
-PRE_UPGRADE_CHECK_IMAGE=$REPO/pre-upgrade-checks
-
 dump_system_info
 
+setupCIBuildEnv
+
+load_docker_cache ${DOCKER_CACHE_DIR}/python-env.tar.gz;
+load_docker_cache ${DOCKER_CACHE_DIR}/jvm-env.tar.gz;
+load_docker_cache ${DOCKER_CACHE_DIR}/go-env.tar.gz;
+load_docker_cache ${DOCKER_CACHE_DIR}/tensorflow-serving-env.tar.gz;
+
+load_docker_cache ${DOCKER_CACHE_DIR}/python-builder.tar.gz;
+load_docker_cache ${DOCKER_CACHE_DIR}/jvm-builder.tar.gz;
+load_docker_cache ${DOCKER_CACHE_DIR}/go-builder.tar.gz;
+
 build_and_push_fission_bundle $REPO/$IMAGE:$TAG
 
 build_and_push_pre_upgrade_check_image $PRE_UPGRADE_CHECK_IMAGE:$TAG
@@ -37,7 +38,6 @@ build_and_push_fetcher $FETCHER_IMAGE:$TAG
 
 build_and_push_builder $BUILDER_IMAGE:$TAG
 
-
 build_and_push_env_runtime python $REPO/python-env:$TAG ""
 build_and_push_env_runtime jvm $REPO/jvm-env:$TAG ""
 build_and_push_env_runtime go $REPO/go-env:$TAG "1.12"
@@ -48,5 +48,3 @@ build_and_push_env_builder jvm $REPO/jvm-env-builder:$TAG $BUILDER_IMAGE:$TAG ""
 build_and_push_env_builder go $REPO/go-env-builder:$TAG $BUILDER_IMAGE:$TAG "1.12"
 
 build_fission_cli
-
-install_and_test $REPO $IMAGE $TAG $FETCHER_IMAGE $TAG $PRUNE_INTERVAL $ROUTER_SERVICE_TYPE $SERVICE_TYPE $PRE_UPGRADE_CHECK_IMAGE
diff --git a/test/save_cache.sh b/test/save_cache.sh
new file mode 100755
index 00000000..3f39c43c
--- /dev/null
+++ b/test/save_cache.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+set -euo pipefail
+
+# Unbound variables cause failure, so this readable if block instead of Parameter Expansion
+if [[ ${TRAVIS_EVENT_TYPE+NOVALUE} == "cronNOVALUE" ]]
+then
+    echo "Skipping build & test, this is cron job for fission upgrade tests"
+    exit 0
+fi
+
+if [ ! -f ${HOME}/.kube/config ]
+then
+    echo "Skipping end to end tests, no cluster credentials"
+    exit 0
+fi
+
+source $(dirname $0)/test_utils.sh
+
+dump_system_info
+
+setupCIBuildEnv
+
+mkdir -p ${DOCKER_CACHE_DIR}
+
+docker save $(docker history -q $REPO/python-env:$TAG | grep -v '<missing>') | gzip > ${DOCKER_CACHE_DIR}/python-env.tar.gz || true
+docker save $(docker history -q $REPO/jvm-env:$TAG | grep -v '<missing>') | gzip > ${DOCKER_CACHE_DIR}/jvm-env.tar.gz || true
+docker save $(docker history -q $REPO/go-env:$TAG | grep -v '<missing>') | gzip > ${DOCKER_CACHE_DIR}/go-env.tar.gz || true
+docker save $(docker history -q $REPO/tensorflow-serving-env:$TAG | grep -v '<missing>') | gzip > ${DOCKER_CACHE_DIR}/tensorflow-serving-env.tar.gz || true
+
+docker save $(docker history -q $REPO/python-env-builder:$TAG | grep -v '<missing>') | gzip > ${DOCKER_CACHE_DIR}/python-builder.tar.gz || true
+docker save $(docker history -q $REPO/jvm-env-builder:$TAG | grep -v '<missing>') | gzip > ${DOCKER_CACHE_DIR}/jvm-builder.tar.gz || true
+docker save $(docker history -q $REPO/go-env-builder:$TAG | grep -v '<missing>') | gzip > ${DOCKER_CACHE_DIR}/go-builder.tar.gz || true
diff --git a/test/test.sh b/test/test.sh
new file mode 100755
index 00000000..15e0dca9
--- /dev/null
+++ b/test/test.sh
@@ -0,0 +1,50 @@
+#!/bin/bash
+
+set -euo pipefail
+
+# Unbound variables cause failure, so this readable if block instead of Parameter Expansion
+if [[ ${TRAVIS_EVENT_TYPE+NOVALUE} == "cronNOVALUE" ]]
+then
+    echo "Skipping build & test, this is cron job for fission upgrade tests"
+    exit 0
+fi
+
+if [ ! -f ${HOME}/.kube/config ]
+then
+    echo "Skipping end to end tests, no cluster credentials"
+    exit 0
+fi
+
+source $(dirname $0)/test_utils.sh
+
+dump_system_info
+
+setupCIBuildEnv
+
+while true; do
+    # ensure that gke cluster is now free for testing
+
+    previous_build_id=$(kubectl --namespace default get configmap in-test --ignore-not-found -o=jsonpath='{.metadata.labels.travisID}')
+
+    build_state=$(curl -s -X GET https://api.travis-ci.org/build/${previous_build_id} \
+        -H "Authorization: token ${TRAVIS_TOKEN}" \
+        -H "Travis-API-Version: 3" | python -c "import sys,json; print json.load(sys.stdin)['state']")
+
+    # If previous build state is not equal to "started" or the previous build id
+    # equals to the current build ID means the previous build is end or restart.
+    # We can remove the configmap safely and start next k8s test safely.
+    if [[ ${TRAVIS_TOKEN} == ${previous_build_id} ]] || [[ $build_state != "started" ]]; then
+        kubectl --namespace default delete configmap -l travisID=${previous_build_id}
+    fi
+
+    created=$(kubectl --namespace default create configmap in-test|grep "created"||true)
+    if [[ -z $created ]]; then
+        echo "Cluster is now in used. Retrying after 15 seconds..."
+        sleep 15
+        continue
+    fi
+    kubectl --namespace default label configmap in-test travisID=${TRAVIS_BUILD_ID}
+    break
+done
+
+install_and_test $REPO $IMAGE $TAG $FETCHER_IMAGE $TAG $PRUNE_INTERVAL $ROUTER_SERVICE_TYPE $SERVICE_TYPE $PRE_UPGRADE_CHECK_IMAGE
diff --git a/test/test_utils.sh b/test/test_utils.sh
index 819c043f..47d88164 100755
--- a/test/test_utils.sh
+++ b/test/test_utils.sh
@@ -53,6 +53,25 @@ getGitCommit() {
     echo $(git rev-parse HEAD)
 }
 
+setupCIBuildEnv() {
+    export REPO=gcr.io/fission-ci
+    export IMAGE=fission-bundle
+    export FETCHER_IMAGE=$REPO/fetcher
+    export BUILDER_IMAGE=$REPO/builder
+    export TAG=test-${TRAVIS_BUILD_ID}
+    export PRUNE_INTERVAL=1 # this variable controls the interval to run archivePruner. The unit is in minutes.
+    export ROUTER_SERVICE_TYPE=LoadBalancer
+    export SERVICE_TYPE=LoadBalancer
+    export PRE_UPGRADE_CHECK_IMAGE=$REPO/pre-upgrade-checks
+}
+
+load_docker_cache() {
+    cache=$1
+    if [ -f ${cache} ]; then
+        gunzip -c ${cache} | docker load;
+    fi
+}
+
 build_and_push_pre_upgrade_check_image() {
     image_tag=$1
     travis_fold_start build_and_push_pre_upgrade_check_image $image_tag
@@ -448,16 +467,17 @@ export FAILURES=0
 
 run_all_tests() {
     id=$1
+    imageTag=$2
 
     export FISSION_NAMESPACE=f-$id
     export FUNCTION_NAMESPACE=f-func-$id
-    export PYTHON_RUNTIME_IMAGE=gcr.io/fission-ci/python-env:test
-    export PYTHON_BUILDER_IMAGE=gcr.io/fission-ci/python-env-builder:test
-    export GO_RUNTIME_IMAGE=gcr.io/fission-ci/go-env:test
-    export GO_BUILDER_IMAGE=gcr.io/fission-ci/go-env-builder:test
-    export JVM_RUNTIME_IMAGE=gcr.io/fission-ci/jvm-env:test
-    export JVM_BUILDER_IMAGE=gcr.io/fission-ci/jvm-env-builder:test
-    export TS_RUNTIME_IMAGE=gcr.io/fission-ci/tensorflow-serving-env:test
+    export PYTHON_RUNTIME_IMAGE=gcr.io/fission-ci/python-env:${imageTag}
+    export PYTHON_BUILDER_IMAGE=gcr.io/fission-ci/python-env-builder:${imageTag}
+    export GO_RUNTIME_IMAGE=gcr.io/fission-ci/go-env:${imageTag}
+    export GO_BUILDER_IMAGE=gcr.io/fission-ci/go-env-builder:${imageTag}
+    export JVM_RUNTIME_IMAGE=gcr.io/fission-ci/jvm-env:${imageTag}
+    export JVM_BUILDER_IMAGE=gcr.io/fission-ci/jvm-env-builder:${imageTag}
+    export TS_RUNTIME_IMAGE=gcr.io/fission-ci/tensorflow-serving-env:${imageTag}
 
     set +e
     export TIMEOUT=900  # 15 minutes per test
@@ -467,8 +487,6 @@ run_all_tests() {
     $ROOT/test/run_test.sh \
         $ROOT/test/tests/test_canary.sh \
         $ROOT/test/tests/mqtrigger/kafka/test_kafka.sh \
-        $ROOT/test/tests/mqtrigger/nats/test_mqtrigger.sh \
-        $ROOT/test/tests/mqtrigger/nats/test_mqtrigger_error.sh \
         $ROOT/test/tests/recordreplay/test_record_greetings.sh \
         $ROOT/test/tests/recordreplay/test_record_rv.sh \
         $ROOT/test/tests/recordreplay/test_recorder_update.sh \
@@ -492,11 +510,13 @@ run_all_tests() {
         $ROOT/test/tests/test_specs/test_spec_multifile.sh \
         $ROOT/test/tests/test_specs/test_spec_merge/test_spec_merge.sh \
         $ROOT/test/tests/test_environments/test_tensorflow_serving_env.sh \
-        $ROOT/test/tests/test_environments/test_go_env.sh
+        $ROOT/test/tests/test_environments/test_go_env.sh \
+        $ROOT/test/tests/mqtrigger/nats/test_mqtrigger.sh \
+        $ROOT/test/tests/mqtrigger/nats/test_mqtrigger_error.sh
     FAILURES=$?
 
     # FIXME: run tests with newdeploy one by one.
-    export JOBS=1
+    export JOBS=2
     $ROOT/test/run_test.sh \
         $ROOT/test/tests/test_backend_newdeploy.sh \
         $ROOT/test/tests/test_environments/test_java_builder.sh \
@@ -562,7 +582,7 @@ install_and_test() {
     # ensure we run tests against with the same git commit version of CLI & server
     fission --version|grep "gitcommit"|tr -d ' '|uniq -c|grep "2 gitcommit"
 
-    run_all_tests $id
+    run_all_tests $id $imageTag
 
     dump_logs $id