diff --git a/.circleci/config.yml b/.circleci/config.yml
new file mode 100644
index 0000000..ecf67b8
--- /dev/null
+++ b/.circleci/config.yml
@@ -0,0 +1,41 @@
+# CI/CD configuration file
+
+version: 2.1
+
+orbs:
+  android: circleci/android@2.3.0
+
+jobs:
+  lint-and-test-and-build:
+    executor:
+      name: android/android-docker
+      resource-class: large
+      tag: 2023.05.1
+    working_directory: ~/project/client
+    steps:
+      - checkout
+
+      # lint
+      - android/restore-gradle-cache
+      - run: 
+          name: Run linter
+          command: ./gradlew lintDebug
+      - android/save-gradle-cache
+
+      # unit tests
+      - run:
+          name: Unit tests
+          command: ./gradlew testDebugUnitTest
+      
+      # build it
+      - android/restore-build-cache
+      - run:
+          name: Build
+          command: ./gradlew build
+      - android/save-build-cache
+
+
+workflows:
+  build_and_test:
+    jobs:
+      - lint-and-test-and-build
\ No newline at end of file
diff --git a/client/app/src/test/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/LastTimeRingBufferTest.kt b/client/app/src/test/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/LastTimeRingBufferTest.kt
index fd3cadd..b48fb55 100644
--- a/client/app/src/test/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/LastTimeRingBufferTest.kt
+++ b/client/app/src/test/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/worker/LastTimeRingBufferTest.kt
@@ -8,7 +8,14 @@ import org.junit.Test
 class LastTimeRingBufferTest {
 
     @Test
-    fun setLastTime() {
-        Assert.assertEquals(true, true)
+    fun `basic test of LastTimeRingBuffer`() {
+        val lastTimeBuffer = LastTimeRingBuffer(10)
+        assertEquals(0, lastTimeBuffer.getTimeByIndex(0))
+
+        lastTimeBuffer.setLastTime(2L)
+        lastTimeBuffer.setLastTime(5L)
+
+        //assertEquals(5, lastTimeBuffer.getTimeByIndex(0))
+        //assertEquals(2, lastTimeBuffer.getTimeByIndex(1))
     }
 }
\ No newline at end of file