diff --git a/native_client/java/Makefile b/native_client/java/Makefile
index 3dda412d..34426e0b 100644
--- a/native_client/java/Makefile
+++ b/native_client/java/Makefile
@@ -3,6 +3,7 @@
 include ../definitions.mk
 
 ARCHS := $(shell grep 'ABI_FILTERS' libdeepspeech/gradle.properties | cut -d'=' -f2 | sed -e 's/;/ /g')
+GRADLE ?= ./gradlew
 
 all: apk
 
@@ -10,7 +11,7 @@ clean: apk-clean
 	rm -rf *.java jni/deepspeech_wrap.cpp
 
 apk-clean:
-	./gradlew clean
+	$(GRADLE) clean
 
 libs-clean:
 	rm -fr libdeepspeech/libs/*/libdeepspeech.so
@@ -20,11 +21,11 @@ libdeepspeech/libs/%/libdeepspeech.so:
 	cp ${TFDIR}/bazel-out/$*-*/bin/native_client/libdeepspeech.so libdeepspeech/libs/$*/
 
 apk: apk-clean bindings $(patsubst %,libdeepspeech/libs/%/libdeepspeech.so,$(ARCHS))
-	./gradlew build
+	$(GRADLE) build
 
 maven-bundle: apk
-	./gradlew uploadArchives
-	./gradlew zipMavenArtifacts
+	$(GRADLE) uploadArchives
+	$(GRADLE) zipMavenArtifacts
 
 bindings: clean
 	swig -c++ -java -package org.mozilla.deepspeech.libdeepspeech -outdir libdeepspeech/src/main/java/org/mozilla/deepspeech/libdeepspeech/ -o jni/deepspeech_wrap.cpp jni/deepspeech.i
diff --git a/native_client/java/build.gradle b/native_client/java/build.gradle
index df7d1d27..be1f2abc 100644
--- a/native_client/java/build.gradle
+++ b/native_client/java/build.gradle
@@ -9,7 +9,6 @@ buildscript {
     dependencies {
         classpath 'com.android.tools.build:gradle:3.2.1'
 
-
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }
diff --git a/taskcluster/.build.yml b/taskcluster/.build.yml
index c1d4bf4c..7e9809e5 100644
--- a/taskcluster/.build.yml
+++ b/taskcluster/.build.yml
@@ -27,3 +27,12 @@ build:
   homebrew:
     url: ''
     namespace: ''
+  cache:
+    url: ''
+    namespace: ''
+  android_cache:
+    url: ''
+    namespace: ''
+  gradle_cache:
+    url: ''
+    namespace: ''
diff --git a/taskcluster/.shared.yml b/taskcluster/.shared.yml
index ce5445bf..e762ebd8 100644
--- a/taskcluster/.shared.yml
+++ b/taskcluster/.shared.yml
@@ -8,6 +8,9 @@ python:
 tensorflow:
   packages_trusty:
     apt: 'make build-essential gfortran git libblas-dev liblapack-dev libsox-dev libmagic-dev libgsm1-dev libltdl-dev libpng-dev python zlib1g-dev'
+java:
+  packages_trusty:
+    apt: 'apt-get -qq -y install curl software-properties-common wget unzip && add-apt-repository --yes ppa:openjdk-r/ppa && apt-get -qq update && DEBIAN_FRONTEND=noninteractive apt-get -qq -y --force-yes install openjdk-8-jdk && java -version && update-ca-certificates -f'
 electronjs:
   packages_xenial:
     apt: 'libatk1.0-0 libatk-bridge2.0-0 libcairo2 libcups2 libdbus-1-3 libgdk-pixbuf2.0-0 libgtk-3-0 libnspr4 libnss3 libpango-1.0-0 libpangocairo-1.0-0 libx11-xcb1 libxcomposite1 libxcursor1 libxdamage1 libxfixes3 libxi6 libxrandr2 libxrender1 libxss1 libxtst6 xvfb'
@@ -55,6 +58,35 @@ system:
   homebrew_tests:
     url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.homebrew_tests.4/artifacts/public/homebrew_tests.tar.gz'
     namespace: 'project.deepspeech.homebrew_tests.4'
+  android_cache:
+    arm64_v8a:
+      android_24:
+        url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.android_cache.arm64-v8a.android-24.4/artifacts/public/android_cache.tar.gz'
+        namespace: 'project.deepspeech.android_cache.arm64-v8a.android-24.4'
+      android_25:
+        url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.android_cache.arm64-v8a.android-25.4/artifacts/public/android_cache.tar.gz'
+        namespace: 'project.deepspeech.android_cache.arm64-v8a.android-25.4'
+    armeabi_v7a:
+      android_24:
+        url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.android_cache.armeabi-v7a.android-24.4/artifacts/public/android_cache.tar.gz'
+        namespace: 'project.deepspeech.android_cache.armeabi-v7a.android-24.4'
+      android_25:
+        url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.android_cache.armeabi-v7a.android-25.4/artifacts/public/android_cache.tar.gz'
+        namespace: 'project.deepspeech.android_cache.armeabi-v7a.android-25.4'
+    x86_64:
+      android_24:
+        url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.android_cache.x86_64.android-24.4/artifacts/public/android_cache.tar.gz'
+        namespace: 'project.deepspeech.android_cache.x86_64.android-24.4'
+      android_25:
+        url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.android_cache.x86_64.android-25.4/artifacts/public/android_cache.tar.gz'
+        namespace: 'project.deepspeech.android_cache.x86_64.android-25.4'
+    sdk:
+      android_27:
+        url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.android_cache.sdk.android-27.4/artifacts/public/android_cache.tar.gz'
+        namespace: 'project.deepspeech.android_cache.sdk.android-27.4'
+  gradle_cache:
+    url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.gradle.4/artifacts/public/gradle.tar.gz'
+    namespace: 'project.deepspeech.gradle.4'
   pyenv:
     linux:
       url: 'https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.pyenv.linux.5/artifacts/public/pyenv.tar.gz'
diff --git a/taskcluster/android-apk-build.sh b/taskcluster/android-apk-build.sh
index 2cbbee14..9259995e 100755
--- a/taskcluster/android-apk-build.sh
+++ b/taskcluster/android-apk-build.sh
@@ -8,6 +8,4 @@ source $(dirname "$0")/tc-tests-utils.sh
 
 source ${DS_ROOT_TASK}/DeepSpeech/tf/tc-vars.sh
 
-android_install_sdk_platform
-
 do_deepspeech_java_apk_build
diff --git a/taskcluster/android-cache-arm64-v8a-android-24.yml b/taskcluster/android-cache-arm64-v8a-android-24.yml
new file mode 100644
index 00000000..a8fef42f
--- /dev/null
+++ b/taskcluster/android-cache-arm64-v8a-android-24.yml
@@ -0,0 +1,14 @@
+build:
+  template_file: android_cache-opt-base.tyml
+  system_setup:
+    >
+      ${java.packages_trusty.apt}
+  cache:
+    url: ${system.android_cache.arm64_v8a.android_24.url}
+    namespace: ${system.android_cache.arm64_v8a.android_24.namespace}
+  scripts:
+    build: "taskcluster/android_cache-build.sh arm64-v8a android-24"
+    package: "taskcluster/android_cache-package.sh"
+  metadata:
+    name: "Builds Android cache arm64-v8a / android-24"
+    description: "Setup an Android SDK / emulator cache for Android arm64-v8a / android-24"
diff --git a/taskcluster/android-cache-arm64-v8a-android-25.yml b/taskcluster/android-cache-arm64-v8a-android-25.yml
new file mode 100644
index 00000000..7dca05ea
--- /dev/null
+++ b/taskcluster/android-cache-arm64-v8a-android-25.yml
@@ -0,0 +1,14 @@
+build:
+  template_file: android_cache-opt-base.tyml
+  system_setup:
+    >
+      ${java.packages_trusty.apt}
+  cache:
+    url: ${system.android_cache.arm64_v8a.android_25.url}
+    namespace: ${system.android_cache.arm64_v8a.android_25.namespace}
+  scripts:
+    build: "taskcluster/android_cache-build.sh arm64-v8a android-25"
+    package: "taskcluster/android_cache-package.sh"
+  metadata:
+    name: "Builds Android cache arm64-v8a / android-25"
+    description: "Setup an Android SDK / emulator cache for Android arm64-v8a / android-25"
diff --git a/taskcluster/android-cache-armeabi-v7a-android-24.yml b/taskcluster/android-cache-armeabi-v7a-android-24.yml
new file mode 100644
index 00000000..605f0e92
--- /dev/null
+++ b/taskcluster/android-cache-armeabi-v7a-android-24.yml
@@ -0,0 +1,14 @@
+build:
+  template_file: android_cache-opt-base.tyml
+  system_setup:
+    >
+      ${java.packages_trusty.apt}
+  cache:
+    url: ${system.android_cache.armeabi_v7a.android_24.url}
+    namespace: ${system.android_cache.armeabi_v7a.android_24.namespace}
+  scripts:
+    build: "taskcluster/android_cache-build.sh armeabi-v7a android-24"
+    package: "taskcluster/android_cache-package.sh"
+  metadata:
+    name: "Builds Android cache armeabi-v7a / android-24"
+    description: "Setup an Android SDK / emulator cache for Android armeabi-v7a / android-24"
diff --git a/taskcluster/android-cache-armeabi-v7a-android-25.yml b/taskcluster/android-cache-armeabi-v7a-android-25.yml
new file mode 100644
index 00000000..6089d940
--- /dev/null
+++ b/taskcluster/android-cache-armeabi-v7a-android-25.yml
@@ -0,0 +1,14 @@
+build:
+  template_file: android_cache-opt-base.tyml
+  system_setup:
+    >
+      ${java.packages_trusty.apt}
+  cache:
+    url: ${system.android_cache.armeabi_v7a.android_25.url}
+    namespace: ${system.android_cache.armeabi_v7a.android_25.namespace}
+  scripts:
+    build: "taskcluster/android_cache-build.sh armeabi-v7a android-25"
+    package: "taskcluster/android_cache-package.sh"
+  metadata:
+    name: "Builds Android cache armeabi-v7a / android-25"
+    description: "Setup an Android SDK / emulator cache for Android armeabi-v7a / android-25"
diff --git a/taskcluster/android-cache-sdk-android-27.yml b/taskcluster/android-cache-sdk-android-27.yml
new file mode 100644
index 00000000..7632e5b8
--- /dev/null
+++ b/taskcluster/android-cache-sdk-android-27.yml
@@ -0,0 +1,14 @@
+build:
+  template_file: android_cache-opt-base.tyml
+  system_setup:
+    >
+      ${java.packages_trusty.apt}
+  cache:
+    url: ${system.android_cache.sdk.android_27.url}
+    namespace: ${system.android_cache.sdk.android_27.namespace}
+  scripts:
+    build: "taskcluster/android_cache-build.sh sdk android-27"
+    package: "taskcluster/android_cache-package.sh"
+  metadata:
+    name: "Builds Android cache sdk / android-27"
+    description: "Setup an Android SDK / emulator cache for Android sdk / android-27"
diff --git a/taskcluster/android-cache-x86_64-android-24.yml b/taskcluster/android-cache-x86_64-android-24.yml
new file mode 100644
index 00000000..38013d08
--- /dev/null
+++ b/taskcluster/android-cache-x86_64-android-24.yml
@@ -0,0 +1,14 @@
+build:
+  template_file: android_cache-opt-base.tyml
+  system_setup:
+    >
+      ${java.packages_trusty.apt}
+  cache:
+    url: ${system.android_cache.x86_64.android_24.url}
+    namespace: ${system.android_cache.x86_64.android_24.namespace}
+  scripts:
+    build: "taskcluster/android_cache-build.sh x86_64 android-24"
+    package: "taskcluster/android_cache-package.sh"
+  metadata:
+    name: "Builds Android cache x86_64 / android-24"
+    description: "Setup an Android SDK / emulator cache for Android x86_64 / android-24"
diff --git a/taskcluster/android-cache-x86_64-android-25.yml b/taskcluster/android-cache-x86_64-android-25.yml
new file mode 100644
index 00000000..6f57be42
--- /dev/null
+++ b/taskcluster/android-cache-x86_64-android-25.yml
@@ -0,0 +1,14 @@
+build:
+  template_file: android_cache-opt-base.tyml
+  system_setup:
+    >
+      ${java.packages_trusty.apt}
+  cache:
+    url: ${system.android_cache.x86_64.android_25.url}
+    namespace: ${system.android_cache.x86_64.android_25.namespace}
+  scripts:
+    build: "taskcluster/android_cache-build.sh x86_64 android-25"
+    package: "taskcluster/android_cache-package.sh"
+  metadata:
+    name: "Builds Android cache x86_64 / android-25"
+    description: "Setup an Android SDK / emulator cache for Android / x86_64 android-25"
diff --git a/taskcluster/android-java-opt.yml b/taskcluster/android-java-opt.yml
index 69f44dc7..7ca7d0f2 100644
--- a/taskcluster/android-java-opt.yml
+++ b/taskcluster/android-java-opt.yml
@@ -5,17 +5,22 @@ build:
     - "android-armv7-cpu-opt"
     - "android-x86_64-cpu-opt"
     - "pyenv-linux-amd64"
+    - "gradle-cache"
+    - "android-cache-sdk-android-27"
   routes:
     - "index.project.deepspeech.deepspeech.native_client.${event.head.branchortag}.android-apk"
     - "index.project.deepspeech.deepspeech.native_client.${event.head.branchortag}.${event.head.sha}.android-apk"
     - "index.project.deepspeech.deepspeech.native_client.android-apk.${event.head.sha}"
   system_setup:
     >
-      apt-get -qq -y install curl software-properties-common &&
-      add-apt-repository --yes ppa:openjdk-r/ppa && apt-get -qq update &&
-      DEBIAN_FRONTEND=noninteractive apt-get -qq -y --force-yes install openjdk-8-jdk &&
-      java -version && update-ca-certificates -f
+      ${java.packages_trusty.apt}
   tensorflow: "https://community-tc.services.mozilla.com/api/index/v1/task/project.deepspeech.tensorflow.pip.r1.15.ceb46aae5836a0f648a2c3da5942af2b7d1b98bf.android-armv7/artifacts/public/home.tar.xz"
+  gradle_cache:
+    url: ${system.gradle_cache.url}
+    namespace: ${system.gradle_cache.namespace}
+  android_cache:
+    url: ${system.android_cache.sdk.android_27.url}
+    namespace: ${system.android_cache.sdk.android_27.namespace}
   scripts:
     build: "taskcluster/android-apk-build.sh"
     package: "taskcluster/android-apk-package.sh"
diff --git a/taskcluster/android_cache-build.sh b/taskcluster/android_cache-build.sh
new file mode 100755
index 00000000..c22ece47
--- /dev/null
+++ b/taskcluster/android_cache-build.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+set -xe
+
+source $(dirname "$0")/tc-tests-utils.sh
+
+arm_flavor=$1
+api_level=$2
+
+export ANDROID_HOME=${ANDROID_SDK_HOME}
+
+android_install_ndk
+
+android_install_sdk
+
+# Required for running APK tests later
+android_install_sdk_platform "android-27"
+
+if [ "${arm_flavor}" != "sdk" ]; then
+  android_setup_emulator "${arm_flavor}" "${api_level}"
+fi;
diff --git a/taskcluster/android_cache-opt-base.tyml b/taskcluster/android_cache-opt-base.tyml
new file mode 100644
index 00000000..b44778aa
--- /dev/null
+++ b/taskcluster/android_cache-opt-base.tyml
@@ -0,0 +1,52 @@
+$if: 'event.event in build.allowed'
+then:
+  taskId: ${taskcluster.taskId}
+  provisionerId: ${taskcluster.docker.provisionerId}
+  workerType: ${taskcluster.docker.workerType}
+  taskGroupId: ${taskcluster.taskGroupId}
+  schedulerId: ${taskcluster.schedulerId}
+  created: { $fromNow: '0 sec' }
+  deadline: { $fromNow: '1 day' }
+  expires: { $fromNow: '6 months' }
+  scopes:
+    - "index:insert-task:project.deepspeech.*"
+
+  payload:
+    maxRunTime: { $eval: to_int(build.maxRunTime) }
+    image: ${build.docker_image}
+
+    features:
+      taskclusterProxy: true
+
+    command:
+      - "/bin/bash"
+      - "--login"
+      - "-cxe"
+      - $let:
+          extraSystemSetup: { $eval: strip(str(build.system_setup)) }
+          taskIndexExpire: { $fromNow: '6 months' }
+        in: >
+          (apt-get -qq -y remove --purge ubuntu-advantage-tools || true) &&
+          apt-get -qq update && apt-get -qq -y install curl git && ${extraSystemSetup};
+          cache_file=`curl -sSIL -o /dev/null -w "%{http_code}" ${build.cache.url}` &&
+          if [ "$cache_file" != "200" ]; then
+            ${extraSystemSetup} &&
+            adduser --system --home ${system.homedir.linux} ${system.username} && cd ${system.homedir.linux}/ &&
+            mkdir -p /tmp/artifacts/ && chmod 777 /tmp/artifacts &&
+            echo -e "#!/bin/bash\nset -xe\n env && id && git clone --quiet ${event.head.repo.url} ~/DeepSpeech/ds/ && cd ~/DeepSpeech/ds && git checkout --quiet ${event.head.sha}" > /tmp/clone.sh && chmod +x /tmp/clone.sh &&
+            sudo -H -u ${system.username} /bin/bash /tmp/clone.sh &&
+            sudo -H -u ${system.username} --preserve-env /bin/bash ${system.homedir.linux}/DeepSpeech/ds/${build.scripts.build} &&
+            sudo -H -u ${system.username} --preserve-env /bin/bash ${system.homedir.linux}/DeepSpeech/ds/${build.scripts.package} ${taskIndexExpire} taskcluster ${build.cache.namespace}
+          fi;
+
+    artifacts:
+      "public":
+        type: "directory"
+        path: "/tmp/artifacts/"
+        expires: { $fromNow: '6 months' }
+
+  metadata:
+    name: ${build.metadata.name}
+    description: ${build.metadata.description}
+    owner: ${event.head.user.email}
+    source: ${event.head.repo.url}
diff --git a/taskcluster/android_cache-package.sh b/taskcluster/android_cache-package.sh
new file mode 100755
index 00000000..22ec767d
--- /dev/null
+++ b/taskcluster/android_cache-package.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -xe
+
+TC_EXPIRE=$1
+TC_INSTANCE=$2
+TC_INDEX=$3
+
+source $(dirname "$0")/tc-tests-utils.sh
+
+cd $HOME/ && tar -czf $TASKCLUSTER_ARTIFACTS/android_cache.tar.gz DeepSpeech/Android/
+
+if [ ! -z "${TC_EXPIRE}" -a ! -z "${TC_INSTANCE}" -a ! -z "${TC_INDEX}" ]; then
+    curl -sSL --fail -X PUT \
+        -H "Content-Type: application/json" \
+        -d "{\"taskId\":\"$TASK_ID\",\"rank\":0,\"expires\":\"${TC_EXPIRE}\",\"data\":{}}" \
+        "http://${TC_INSTANCE}/index/v1/task/${TC_INDEX}"
+fi;
diff --git a/taskcluster/gradle-build.sh b/taskcluster/gradle-build.sh
new file mode 100755
index 00000000..48675bb6
--- /dev/null
+++ b/taskcluster/gradle-build.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+
+set -xe
+
+source $(dirname "$0")/tc-tests-utils.sh
+
+if [ -z "${GRADLE_USER_HOME}" ]; then
+  echo "Unable to generate cache without an emplacement"
+  exit 1
+fi;
+
+mkdir -p ${GRADLE_USER_HOME}
+
+export ANDROID_HOME=${ANDROID_SDK_HOME}
+
+# Gradle likes to play with us.
+android_install_ndk
+android_install_sdk
+
+pushd ${DS_ROOT_TASK}/DeepSpeech/ds/native_client/java/
+  ./gradlew androidDependencies dependentComponents dependencies
+  # we need this for aapt2 binary
+  ./gradlew buildNeeded || true # will try javac which is doomed to fail
+  ./gradlew --refresh-dependencies
+popd
+
+du -hs ${GRADLE_USER_HOME}/*
diff --git a/taskcluster/gradle-cache.yml b/taskcluster/gradle-cache.yml
new file mode 100644
index 00000000..334545c3
--- /dev/null
+++ b/taskcluster/gradle-cache.yml
@@ -0,0 +1,14 @@
+build:
+  template_file: android_cache-opt-base.tyml
+  system_setup:
+    >
+      ${java.packages_trusty.apt}
+  cache:
+    url: ${system.gradle_cache.url}
+    namespace: ${system.gradle_cache.namespace}
+  scripts:
+    build: "taskcluster/gradle-build.sh"
+    package: "taskcluster/gradle-package.sh"
+  metadata:
+    name: "Builds Gradle cache"
+    description: "Setup a Gradle cache for Android"
diff --git a/taskcluster/gradle-package.sh b/taskcluster/gradle-package.sh
new file mode 100755
index 00000000..495c05e8
--- /dev/null
+++ b/taskcluster/gradle-package.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -xe
+
+TC_EXPIRE=$1
+TC_INSTANCE=$2
+TC_INDEX=$3
+
+source $(dirname "$0")/tc-tests-utils.sh
+
+cd ${GRADLE_USER_HOME}/../ && tar -czf $TASKCLUSTER_ARTIFACTS/gradle.tar.gz gradle-cache/
+
+if [ ! -z "${TC_EXPIRE}" -a ! -z "${TC_INSTANCE}" -a ! -z "${TC_INDEX}" ]; then
+    curl -sSL --fail -X PUT \
+        -H "Content-Type: application/json" \
+        -d "{\"taskId\":\"$TASK_ID\",\"rank\":0,\"expires\":\"${TC_EXPIRE}\",\"data\":{}}" \
+        "http://${TC_INSTANCE}/index/v1/task/${TC_INDEX}"
+fi;
diff --git a/taskcluster/linux-opt-base.tyml b/taskcluster/linux-opt-base.tyml
index dd50397a..2a697bf0 100644
--- a/taskcluster/linux-opt-base.tyml
+++ b/taskcluster/linux-opt-base.tyml
@@ -48,7 +48,7 @@ then:
           adduser --system --home ${system.homedir.linux} ${system.username} &&
           apt-get -qq update && apt-get -qq -y install ${tensorflow.packages_trusty.apt} pixz pkg-config realpath unzip wget zip && ${extraSystemSetup} &&
           cd ${system.homedir.linux}/ &&
-          echo -e "#!/bin/bash\nset -xe\n env && id && (wget -O - $TENSORFLOW_BUILD_ARTIFACT | pixz -d | tar -C ${system.homedir.linux}/ -xf - ) && git clone --quiet ${event.head.repo.url} ~/DeepSpeech/ds/ && cd ~/DeepSpeech/ds && git checkout --quiet ${event.head.sha} && ln -s ~/DeepSpeech/ds/native_client/ ~/DeepSpeech/tf/native_client && mkdir -p ${system.homedir.linux}/.cache/node-gyp/ && wget -O - ${system.node_gyp_cache.url} | tar -C ${system.homedir.linux}/.cache/node-gyp/ -xzf - && mkdir -p ${system.homedir.linux}/ds-swig/bin/ && wget -O - ${system.swig.cache.linux_amd64} | tar -C ${system.homedir.linux}/ds-swig/ -xzf - && mkdir -p ${system.homedir.linux}/pyenv-root/ && wget -O - ${system.pyenv.linux.url} | tar -C ${system.homedir.linux}/pyenv-root/ -xzf -" > /tmp/clone.sh && chmod +x /tmp/clone.sh &&
+          echo -e "#!/bin/bash\nset -xe\n env && id && (wget -O - $TENSORFLOW_BUILD_ARTIFACT | pixz -d | tar -C ${system.homedir.linux}/ -xf - ) && git clone --quiet ${event.head.repo.url} ~/DeepSpeech/ds/ && cd ~/DeepSpeech/ds && git checkout --quiet ${event.head.sha} && ln -s ~/DeepSpeech/ds/native_client/ ~/DeepSpeech/tf/native_client && mkdir -p ${system.homedir.linux}/.cache/node-gyp/ && wget -O - ${system.node_gyp_cache.url} | tar -C ${system.homedir.linux}/.cache/node-gyp/ -xzf - && mkdir -p ${system.homedir.linux}/ds-swig/bin/ && wget -O - ${system.swig.cache.linux_amd64} | tar -C ${system.homedir.linux}/ds-swig/ -xzf - && mkdir -p ${system.homedir.linux}/pyenv-root/ && wget -O - ${system.pyenv.linux.url} | tar -C ${system.homedir.linux}/pyenv-root/ -xzf - && if [ ! -z "${build.gradle_cache.url}" ]; then wget -O - ${build.gradle_cache.url} | tar -C ${system.homedir.linux}/ -xzf - ; fi && if [ ! -z "${build.android_cache.url}" ]; then wget -O - ${build.android_cache.url} | tar -C ${system.homedir.linux}/ -xzf - ; fi;" > /tmp/clone.sh && chmod +x /tmp/clone.sh &&
           sudo -H -u ${system.username} /bin/bash /tmp/clone.sh && ${extraSystemConfig} &&
           sudo -H -u ${system.username} --preserve-env /bin/bash ${system.homedir.linux}/DeepSpeech/ds/${build.scripts.build} &&
           sudo -H -u ${system.username} /bin/bash ${system.homedir.linux}/DeepSpeech/ds/${build.scripts.package}
diff --git a/taskcluster/tc-all-vars.sh b/taskcluster/tc-all-vars.sh
index 8740725f..cb836e83 100755
--- a/taskcluster/tc-all-vars.sh
+++ b/taskcluster/tc-all-vars.sh
@@ -75,6 +75,7 @@ export DS_EXAMPLEDIR=${DS_ROOT_TASK}/DeepSpeech/examples
 
 export DS_VERSION="$(cat ${DS_DSDIR}/VERSION)"
 
+export GRADLE_USER_HOME=${DS_ROOT_TASK}/gradle-cache
 export ANDROID_SDK_HOME=${DS_ROOT_TASK}/DeepSpeech/Android/SDK/
 export ANDROID_NDK_HOME=${DS_ROOT_TASK}/DeepSpeech/Android/android-ndk-r18b/
 
diff --git a/taskcluster/tc-android-apk-tests.sh b/taskcluster/tc-android-apk-tests.sh
index fec910bd..7074aa85 100644
--- a/taskcluster/tc-android-apk-tests.sh
+++ b/taskcluster/tc-android-apk-tests.sh
@@ -15,12 +15,10 @@ model_name=$(basename "${model_source}")
 
 download_data
 
-android_install_ndk
-
-android_setup_emulator "${arm_flavor}" "${api_level}"
-
 force_java_apk_x86_64
 
+android_start_emulator "${arm_flavor}" "${api_level}"
+
 # Required, because of "gradle connectedAndroidTest" deps
 do_deepspeech_java_apk_build
 
diff --git a/taskcluster/tc-android-ds-tests.sh b/taskcluster/tc-android-ds-tests.sh
index b9c70d03..257a9496 100755
--- a/taskcluster/tc-android-ds-tests.sh
+++ b/taskcluster/tc-android-ds-tests.sh
@@ -24,7 +24,7 @@ fi
 
 download_material "${TASKCLUSTER_TMP_DIR}/ds"
 
-android_setup_emulator "${arm_flavor}" "${api_level}"
+android_start_emulator "${arm_flavor}" "${api_level}"
 
 android_setup_ndk_data
 
diff --git a/taskcluster/tc-android-utils.sh b/taskcluster/tc-android-utils.sh
index dfd75212..4deffd5a 100755
--- a/taskcluster/tc-android-utils.sh
+++ b/taskcluster/tc-android-utils.sh
@@ -43,9 +43,9 @@ do_deepspeech_java_apk_build()
     fi;
   done;
 
-  make -C native_client/java/
+  make GRADLE="./gradlew " -C native_client/java/
 
-  make -C native_client/java/ maven-bundle
+  make GRADLE="./gradlew " -C native_client/java/ maven-bundle
 }
 
 android_run_tests()
@@ -100,8 +100,6 @@ android_install_ndk()
 
 android_setup_emulator()
 {
-  android_install_sdk
-
   if [ -z "${ANDROID_SDK_HOME}" ]; then
     echo "No Android SDK home available, aborting."
     exit 1
@@ -112,8 +110,30 @@ android_setup_emulator()
     exit 1
   fi;
 
-  flavor=$1
-  api_level=${2:-android-25}
+  local _flavor=$1
+  local _api_level=${2:-android-25}
+
+  export PATH=${ANDROID_SDK_HOME}/tools/bin/:${ANDROID_SDK_HOME}/platform-tools/:$PATH
+  export DS_BINARY_PREFIX="adb shell LD_LIBRARY_PATH=${ANDROID_TMP_DIR}/ds/ ${ANDROID_TMP_DIR}/ds/"
+
+  # Pipe yes in case of license being shown
+  yes | sdkmanager --update
+  yes | sdkmanager --install "emulator"
+
+  android_install_sdk_platform "${_api_level}"
+
+  # Same, yes in case of license
+  yes | sdkmanager --install "system-images;${_api_level};google_apis;${_flavor}"
+
+  android_sdk_accept_licenses
+
+  avdmanager create avd --name "${_flavor}-ds-pixel-${_api_level}" --device 17 --package "system-images;${_api_level};google_apis;${_flavor}"
+}
+
+android_start_emulator()
+{
+  local _flavor=$1
+  local _api_level=${2:-android-25}
 
   export PATH=${ANDROID_SDK_HOME}/tools/bin/:${ANDROID_SDK_HOME}/platform-tools/:$PATH
   export DS_BINARY_PREFIX="adb shell LD_LIBRARY_PATH=${ANDROID_TMP_DIR}/ds/ ${ANDROID_TMP_DIR}/ds/"
@@ -121,25 +141,11 @@ android_setup_emulator()
   # minutes (2 minutes by default)
   export ADB_INSTALL_TIMEOUT=8
 
-  # Pipe yes in case of license being shown
-  yes | sdkmanager --update
-  yes | sdkmanager --install "emulator"
-
-  android_install_sdk_platform "${api_level}"
-
-  # Same, yes in case of license
-  yes | sdkmanager --install "system-images;${api_level};google_apis;${flavor}"
-
-  android_sdk_accept_licenses
-
-  avdmanager create avd --name "ds-pixel" --device 17 --package "system-images;${api_level};google_apis;${flavor}"
-
   # Use xvfb because:
   #  > emulator: INFO: QtLogger.cpp:68: Warning: could not connect to display  ((null):0, (null))
-
   # -accel on is needed otherwise it is too slow, but it will require KVM support exposed
   pushd ${ANDROID_SDK_HOME}
-    xvfb-run ./tools/emulator -verbose -avd ds-pixel -no-skin -no-audio -no-window -no-boot-anim -accel off &
+    xvfb-run ./tools/emulator -verbose -avd "${_flavor}-ds-pixel-${_api_level}" -no-skin -no-audio -no-window -no-boot-anim -accel off &
     emulator_rc=$?
     export ANDROID_DEVICE_EMULATOR=$!
   popd
@@ -159,7 +165,7 @@ android_setup_emulator()
 
 android_install_sdk_platform()
 {
-  api_level=${1:-android-27}
+  local _api_level=${1:-android-27}
 
   if [ -z "${ANDROID_SDK_HOME}" ]; then
     echo "No Android SDK home available, aborting."
@@ -170,8 +176,10 @@ android_install_sdk_platform()
 
   # Pipe yes in case of license being shown
   yes | sdkmanager --update
+  yes | sdkmanager --install "build-tools;28.0.3"
+  yes | sdkmanager --install "cmake;3.6.4111459"
   yes | sdkmanager --install "platform-tools"
-  yes | sdkmanager --install "platforms;${api_level}"
+  yes | sdkmanager --install "platforms;${_api_level}"
 
   android_sdk_accept_licenses
 }
diff --git a/taskcluster/test-android-opt-base.tyml b/taskcluster/test-android-opt-base.tyml
index cc5d2b56..dda7e963 100644
--- a/taskcluster/test-android-opt-base.tyml
+++ b/taskcluster/test-android-opt-base.tyml
@@ -44,7 +44,7 @@ then:
           ${extraSystemSetup} &&
           adduser --system --home ${system.homedir.linux} ${system.username} &&
           cd ${system.homedir.linux} &&
-          echo -e "#!/bin/bash\nset -xe\n env && id && mkdir ~/DeepSpeech/ && git clone --quiet ${event.head.repo.url} ~/DeepSpeech/ds/ && cd ~/DeepSpeech/ds && git checkout --quiet ${event.head.sha} && mkdir -p ${system.homedir.linux}/ds-swig/bin/ && wget -O - ${system.swig.cache.linux_amd64} | tar -C ${system.homedir.linux}/ds-swig/ -xzf -" > /tmp/clone.sh && chmod +x /tmp/clone.sh &&
+          echo -e "#!/bin/bash\nset -xe\n env && id && mkdir ~/DeepSpeech/ && git clone --quiet ${event.head.repo.url} ~/DeepSpeech/ds/ && cd ~/DeepSpeech/ds && git checkout --quiet ${event.head.sha} && mkdir -p ${system.homedir.linux}/ds-swig/bin/ && wget -O - ${system.swig.cache.linux_amd64} | tar -C ${system.homedir.linux}/ds-swig/ -xzf - && wget -O - ${build.cache.url} | tar -C ${system.homedir.linux} -xzf - && if [ ! -z "${build.gradle_cache.url}" ]; then wget -O - ${build.gradle_cache.url} | tar -C ${system.homedir.linux}/ -xzf - ; fi;" > /tmp/clone.sh && chmod +x /tmp/clone.sh &&
           sudo -H -u ${system.username} /bin/bash /tmp/clone.sh &&
           sudo -H -u ${system.username} --preserve-env /bin/bash ${build.args.tests_cmdline}
 
diff --git a/taskcluster/test-apk-android-24-x86_64-opt.yml b/taskcluster/test-apk-android-24-x86_64-opt.yml
index e311790f..ead96e01 100644
--- a/taskcluster/test-apk-android-24-x86_64-opt.yml
+++ b/taskcluster/test-apk-android-24-x86_64-opt.yml
@@ -4,10 +4,18 @@ build:
     - "swig-linux-amd64"
     - "android-x86_64-cpu-opt"
     - "test-training_16k-linux-amd64-py36m-opt"
+    - "gradle-cache"
+    - "android-cache-x86_64-android-24"
   test_model_task: "test-training_16k-linux-amd64-py36m-opt"
   system_setup:
     >
       apt-get -qq -y install curl make python
+  cache:
+    url: ${system.android_cache.x86_64.android_24.url}
+    namespace: ${system.android_cache.x86_64.android_24.namespace}
+  gradle_cache:
+    url: ${system.gradle_cache.url}
+    namespace: ${system.gradle_cache.namespace}
   args:
     tests_cmdline: "${system.homedir.linux}/DeepSpeech/ds/taskcluster/tc-android-apk-tests.sh x86_64 android-24 16k"
   metadata:
diff --git a/taskcluster/test-apk-android-25-x86_64-opt.yml b/taskcluster/test-apk-android-25-x86_64-opt.yml
index 1273b339..fbf2c655 100644
--- a/taskcluster/test-apk-android-25-x86_64-opt.yml
+++ b/taskcluster/test-apk-android-25-x86_64-opt.yml
@@ -4,10 +4,18 @@ build:
     - "swig-linux-amd64"
     - "android-x86_64-cpu-opt"
     - "test-training_16k-linux-amd64-py36m-opt"
+    - "gradle-cache"
+    - "android-cache-x86_64-android-25"
   test_model_task: "test-training_16k-linux-amd64-py36m-opt"
   system_setup:
     >
       apt-get -qq -y install curl make python
+  cache:
+    url: ${system.android_cache.x86_64.android_25.url}
+    namespace: ${system.android_cache.x86_64.android_25.namespace}
+  gradle_cache:
+    url: ${system.gradle_cache.url}
+    namespace: ${system.gradle_cache.namespace}
   args:
     tests_cmdline: "${system.homedir.linux}/DeepSpeech/ds/taskcluster/tc-android-apk-tests.sh x86_64 android-25 16k"
   metadata:
diff --git a/taskcluster/test-cpp-android-24-arm64-opt.yml b/taskcluster/test-cpp-android-24-arm64-opt.yml
index abd21dc9..5125244f 100644
--- a/taskcluster/test-cpp-android-24-arm64-opt.yml
+++ b/taskcluster/test-cpp-android-24-arm64-opt.yml
@@ -3,6 +3,10 @@ build:
   dependencies:
     - "android-arm64-cpu-opt"
     - "test-training_16k-linux-amd64-py36m-opt"
+    - "android-cache-arm64-v8a-android-24"
+  cache:
+    url: ${system.android_cache.arm64_v8a.android_24.url}
+    namespace: ${system.android_cache.arm64_v8a.android_24.namespace}
   test_model_task: "test-training_16k-linux-amd64-py36m-opt"
   args:
     tests_cmdline: "${system.homedir.linux}/DeepSpeech/ds/taskcluster/tc-android-ds-tests.sh arm64-v8a android-24 16k"
diff --git a/taskcluster/test-cpp-android-24-armv7-opt.yml b/taskcluster/test-cpp-android-24-armv7-opt.yml
index af5b1c6e..37a45300 100644
--- a/taskcluster/test-cpp-android-24-armv7-opt.yml
+++ b/taskcluster/test-cpp-android-24-armv7-opt.yml
@@ -3,6 +3,10 @@ build:
   dependencies:
     - "android-armv7-cpu-opt"
     - "test-training_16k-linux-amd64-py36m-opt"
+    - "android-cache-armeabi-v7a-android-24"
+  cache:
+    url: ${system.android_cache.armeabi_v7a.android_24.url}
+    namespace: ${system.android_cache.armeabi_v7a.android_24.namespace}
   test_model_task: "test-training_16k-linux-amd64-py36m-opt"
   args:
     tests_cmdline: "${system.homedir.linux}/DeepSpeech/ds/taskcluster/tc-android-ds-tests.sh armeabi-v7a android-24 16k"
diff --git a/taskcluster/test-cpp-android-25-arm64-opt.yml b/taskcluster/test-cpp-android-25-arm64-opt.yml
index 7183105e..bc450863 100644
--- a/taskcluster/test-cpp-android-25-arm64-opt.yml
+++ b/taskcluster/test-cpp-android-25-arm64-opt.yml
@@ -3,6 +3,10 @@ build:
   dependencies:
     - "android-arm64-cpu-opt"
     - "test-training_16k-linux-amd64-py36m-opt"
+    - "android-cache-arm64-v8a-android-25"
+  cache:
+    url: ${system.android_cache.arm64_v8a.android_25.url}
+    namespace: ${system.android_cache.arm64_v8a.android_25.namespace}
   test_model_task: "test-training_16k-linux-amd64-py36m-opt"
   args:
     tests_cmdline: "${system.homedir.linux}/DeepSpeech/ds/taskcluster/tc-android-ds-tests.sh arm64-v8a android-25 16k"
diff --git a/taskcluster/test-cpp-android-25-armv7-opt.yml b/taskcluster/test-cpp-android-25-armv7-opt.yml
index 8bb1c8f1..85818edf 100644
--- a/taskcluster/test-cpp-android-25-armv7-opt.yml
+++ b/taskcluster/test-cpp-android-25-armv7-opt.yml
@@ -3,6 +3,10 @@ build:
   dependencies:
     - "android-armv7-cpu-opt"
     - "test-training_16k-linux-amd64-py36m-opt"
+    - "android-cache-armeabi-v7a-android-25"
+  cache:
+    url: ${system.android_cache.armeabi_v7a.android_25.url}
+    namespace: ${system.android_cache.armeabi_v7a.android_25.namespace}
   test_model_task: "test-training_16k-linux-amd64-py36m-opt"
   args:
     tests_cmdline: "${system.homedir.linux}/DeepSpeech/ds/taskcluster/tc-android-ds-tests.sh armeabi-v7a android-25 16k"