diff --git a/.idea/gradle.xml b/.idea/gradle.xml
index f4bb361..cbf7a5a 100644
--- a/.idea/gradle.xml
+++ b/.idea/gradle.xml
@@ -22,7 +22,6 @@
             <option value="$PROJECT_DIR$" />
             <option value="$PROJECT_DIR$/backend" />
             <option value="$PROJECT_DIR$/buildSrc" />
-            <option value="$PROJECT_DIR$/frontend" />
           </set>
         </option>
       </GradleProjectSettings>
diff --git a/.idea/kotlinc.xml b/.idea/kotlinc.xml
index f8467b4..e805548 100644
--- a/.idea/kotlinc.xml
+++ b/.idea/kotlinc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="KotlinJpsPluginSettings">
-    <option name="version" value="1.9.10" />
+    <option name="version" value="1.9.20" />
   </component>
 </project>
\ No newline at end of file
diff --git a/backend/src/main/kotlin/jp/skypencil/kosmo/backend/storage/onmemory/OnMemoryDatabase.kt b/backend/src/main/kotlin/jp/skypencil/kosmo/backend/storage/onmemory/OnMemoryDatabase.kt
index 2318313..bd1fbb9 100644
--- a/backend/src/main/kotlin/jp/skypencil/kosmo/backend/storage/onmemory/OnMemoryDatabase.kt
+++ b/backend/src/main/kotlin/jp/skypencil/kosmo/backend/storage/onmemory/OnMemoryDatabase.kt
@@ -2,7 +2,9 @@ package jp.skypencil.kosmo.backend.storage.onmemory
 
 import jp.skypencil.kosmo.backend.storage.shared.Table
 import jp.skypencil.kosmo.backend.storage.shared.Database
+import org.koin.core.annotation.Singleton
 
+@Singleton
 class OnMemoryDatabase : Database {
     private val tables = mutableMapOf<String, OnMemoryTable>()
     override suspend fun findTable(name: String): Table =
diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
index 15f9044..10ce082 100644
--- a/buildSrc/build.gradle.kts
+++ b/buildSrc/build.gradle.kts
@@ -9,5 +9,6 @@ repositories {
 
 dependencies {
     implementation("com.diffplug.spotless:spotless-plugin-gradle:6.22.0")
-    implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.9.10")
+    implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.9.20")
+    implementation("com.google.devtools.ksp:com.google.devtools.ksp.gradle.plugin:1.9.20-1.0.14")
 }
diff --git a/buildSrc/src/main/kotlin/jp.skypencil.kosmo.kotlin-application-conventions.gradle.kts b/buildSrc/src/main/kotlin/jp.skypencil.kosmo.kotlin-application-conventions.gradle.kts
index 7aa3ff2..ed31bde 100644
--- a/buildSrc/src/main/kotlin/jp.skypencil.kosmo.kotlin-application-conventions.gradle.kts
+++ b/buildSrc/src/main/kotlin/jp.skypencil.kosmo.kotlin-application-conventions.gradle.kts
@@ -1,5 +1,4 @@
 plugins {
     id("jp.skypencil.kosmo.kotlin-common-conventions")
-
     application
 }
diff --git a/buildSrc/src/main/kotlin/jp.skypencil.kosmo.kotlin-common-conventions.gradle.kts b/buildSrc/src/main/kotlin/jp.skypencil.kosmo.kotlin-common-conventions.gradle.kts
index a653dff..a5a002f 100644
--- a/buildSrc/src/main/kotlin/jp.skypencil.kosmo.kotlin-common-conventions.gradle.kts
+++ b/buildSrc/src/main/kotlin/jp.skypencil.kosmo.kotlin-common-conventions.gradle.kts
@@ -1,6 +1,12 @@
 plugins {
     id("org.jetbrains.kotlin.jvm")
     id("com.diffplug.spotless")
+    id("com.google.devtools.ksp")
+}
+
+sourceSets.main {
+    // KSP - To use generated sources
+    java.srcDirs("build/generated/ksp/main/kotlin")
 }
 
 repositories {
@@ -14,7 +20,12 @@ java {
 }
 
 val kotest = "5.8.0"
+val koin = "3.5.0"
+val koinKsp = "1.3.0"
 dependencies {
+    implementation("io.insert-koin:koin-core:$koin")
+    compileOnly("io.insert-koin:koin-annotations:$koinKsp")
+    ksp("io.insert-koin:koin-ksp-compiler:$koinKsp")
     testImplementation("io.kotest:kotest-assertions-core:$kotest")
     testImplementation("io.kotest:kotest-property:$kotest")
     testRuntimeOnly("io.kotest:kotest-runner-junit5:$kotest")
diff --git a/frontend/build.gradle.kts b/frontend/build.gradle.kts
deleted file mode 100644
index b8e4637..0000000
--- a/frontend/build.gradle.kts
+++ /dev/null
@@ -1,3 +0,0 @@
-plugins {
-    id("jp.skypencil.kosmo.kotlin-application-conventions")
-}
diff --git a/frontend/src/main/kotlin/jp/skypencil/kosmo/list/LinkedList.kt b/frontend/src/main/kotlin/jp/skypencil/kosmo/list/LinkedList.kt
deleted file mode 100644
index 5781e6c..0000000
--- a/frontend/src/main/kotlin/jp/skypencil/kosmo/list/LinkedList.kt
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- * This Kotlin source file was generated by the Gradle 'init' task.
- */
-package jp.skypencil.kosmo.list
-
-class LinkedList {
-    private var head: Node? = null
-
-    fun add(element: String) {
-        val newNode = Node(element)
-
-        val it = tail(head)
-        if (it == null) {
-            head = newNode
-        } else {
-            it.next = newNode
-        }
-    }
-
-    private fun tail(head: Node?): Node? {
-        var it: Node?
-
-        it = head
-        while (it?.next != null) {
-            it = it.next
-        }
-
-        return it
-    }
-
-    fun remove(element: String): Boolean {
-        var result = false
-        var previousIt: Node? = null
-        var it: Node? = head
-        while (!result && it != null) {
-            if (0 == element.compareTo(it.data)) {
-                result = true
-                unlink(previousIt, it)
-                break
-            }
-            previousIt = it
-            it = it.next
-        }
-
-        return result
-    }
-
-    private fun unlink(previousIt: Node?, currentIt: Node) {
-        if (currentIt == head) {
-            head = currentIt.next
-        } else {
-            previousIt?.next = currentIt.next
-        }
-    }
-
-    fun size(): Int {
-        var size = 0
-
-        var it = head
-        while (it != null) {
-            ++size
-            it = it.next
-        }
-
-        return size
-    }
-
-    fun get(idx: Int): String {
-        var index = idx
-        var it = head
-        while (index > 0 && it != null) {
-            it = it.next
-            index--
-        }
-
-        if (it == null) {
-            throw IndexOutOfBoundsException("Index is out of range")
-        }
-
-        return it.data
-    }
-
-    private data class Node(val data: String) {
-        var next: Node? = null
-    }
-}
diff --git a/settings.gradle.kts b/settings.gradle.kts
index ed45956..47d533e 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -3,4 +3,4 @@ plugins {
 }
 
 rootProject.name = "kosmo"
-include("backend", "frontend")
+include("backend")