diff --git a/backend/infrastructure/gateway/build.gradle.kts b/backend/infrastructure/gateway/build.gradle.kts
index 08130a53..f2c86b4d 100644
--- a/backend/infrastructure/gateway/build.gradle.kts
+++ b/backend/infrastructure/gateway/build.gradle.kts
@@ -24,6 +24,10 @@ dependencies {
   implementation(projects.backend.infrastructure.monitoring.monitoringClient)
 
   // === GATEWAY-SPEZIFISCHE ABHÄNGIGKEITEN ===
+  // KORREKTUR: Explizite Deklaration von WebFlux, da es in Spring Boot 4.x
+  // anscheinend nicht mehr vollständig transitiv vom Gateway-Starter eingebunden wird.
+  implementation(libs.spring.boot.starter.webflux)
+
   // Kern-Gateway inkl. Security, Actuator, CircuitBreaker, Discovery
   implementation(libs.bundles.gateway.core)
   // Ergänzende Observability (Logging, Jackson)
diff --git a/backend/services/ping/ping-service/build.gradle.kts b/backend/services/ping/ping-service/build.gradle.kts
index 290226c5..27fd7cc5 100644
--- a/backend/services/ping/ping-service/build.gradle.kts
+++ b/backend/services/ping/ping-service/build.gradle.kts
@@ -14,8 +14,10 @@ springBoot {
 }
 
 dependencies {
-  // Platform BOM für zentrale Versionsverwaltung
-  implementation(platform(projects.platform.platformBom))
+  // ULTIMATIVER TEST: Wir umgehen unser lokales BOM und importieren das offizielle Spring Boot BOM direkt.
+  // Wenn dies funktioniert, liegt der Fehler im Aufbau von `:platform:platform-bom`.
+  implementation(platform(libs.spring.boot.dependencies))
+  // implementation(platform(projects.platform.platformBom))
 
   // Platform und Core Dependencies
   implementation(projects.platform.platformDependencies)
diff --git a/backend/services/registry/oeps-importer/build.gradle.kts b/backend/services/registry/oeps-importer/build.gradle.kts
index dd9bee82..7acf3404 100644
--- a/backend/services/registry/oeps-importer/build.gradle.kts
+++ b/backend/services/registry/oeps-importer/build.gradle.kts
@@ -5,9 +5,8 @@ plugins {
 group = "at.mocode"
 version = "1.0.0-SNAPSHOT"
 
-repositories {
-  mavenCentral()
-}
+// The 'repositories' block was removed from here.
+// Repository configuration is now centralized in 'settings.gradle.kts'.
 
 dependencies {
   testImplementation(platform("org.junit:junit-bom:5.10.0"))
diff --git a/build.gradle.kts b/build.gradle.kts
index 2c98af63..c60bcffe 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -40,15 +40,10 @@ allprojects {
   group = "at.mocode"
   version = "1.0.0-SNAPSHOT"
 
-  // Apply common repository configuration
-  repositories {
-    mavenCentral()
-    google()
-    maven { url = uri("https://jitpack.io") }
-    maven { url = uri("https://oss.sonatype.org/content/repositories/snapshots/") }
-    maven { url = uri("https://maven.pkg.jetbrains.space/public/p/compose/dev") }
-    maven { url = uri("https://us-central1-maven.pkg.dev/varabyte-repos/public") }
-  }
+  // The 'repositories' block was removed from here.
+  // Repository configuration is now centralized in 'settings.gradle.kts'
+  // as per modern Gradle best practices. This resolves dependency resolution
+  // conflicts with platforms and Spring Boot 4+.
 }
 
 subprojects {
diff --git a/platform/platform-bom/build.gradle.kts b/platform/platform-bom/build.gradle.kts
index 7f59b677..56c5b73e 100644
--- a/platform/platform-bom/build.gradle.kts
+++ b/platform/platform-bom/build.gradle.kts
@@ -22,22 +22,9 @@ dependencies {
     // `constraints` erzwingt spezifische Versionen für einzelne Bibliotheken.
     // Alle Versionen werden sicher aus `libs.versions.toml` bezogen.
     constraints {
-        // --- Spring Boot Core Constraints (hart pinnen, um Leaks von M-Releases zu verhindern) ---
-        api("org.springframework.boot:spring-boot:${libs.versions.springBoot.get()}")
-        api("org.springframework.boot:spring-boot-autoconfigure:${libs.versions.springBoot.get()}")
-        api("org.springframework.boot:spring-boot-actuator-autoconfigure:${libs.versions.springBoot.get()}")
-        api("org.springframework.boot:spring-boot-actuator:${libs.versions.springBoot.get()}")
-        api("org.springframework.boot:spring-boot-starter:${libs.versions.springBoot.get()}")
-        api("org.springframework.boot:spring-boot-test:${libs.versions.springBoot.get()}")
-        api("org.springframework.boot:spring-boot-test-autoconfigure:${libs.versions.springBoot.get()}")
-        // Zusätzliche Boot-Module, die in neueren Versionen als eigenständige Artefakte vorliegen
-        // und in AutoConfigurations referenziert werden. Hart pinnen, um Versions-Skew in Tests zu vermeiden.
-        // HttpClient AutoConfig und Settings
-        api("org.springframework.boot:spring-boot-http:${libs.versions.springBoot.get()}")
-        api("org.springframework.boot:spring-boot-autoconfigure-processor:${libs.versions.springBoot.get()}")
-        api("org.springframework.boot:spring-boot-http-converter:${libs.versions.springBoot.get()}")
-        // Kontext- und Properties-Unterstützung, auf die PropertyMapper intern zugreifen kann
-        api("org.springframework.boot:spring-boot-configuration-processor:${libs.versions.springBoot.get()}")
+        // --- Spring Boot Core Constraints wurden entfernt. ---
+        // Die Versionen werden jetzt vollständig durch das importierte Spring Boot BOM verwaltet.
+        // Das ist der saubere und empfohlene Weg.
 
         // --- Utilities & Other ---
         api(libs.caffeine)
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 7deee9bd..d05243a9 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -21,7 +21,6 @@ plugins {
 }
 
 dependencyResolutionManagement {
-
   repositories {
     mavenCentral()
     google()