diff --git a/backend-java/build.gradle b/backend-java/build.gradle
index 34f9358..8f8a58e 100644
--- a/backend-java/build.gradle
+++ b/backend-java/build.gradle
@@ -28,6 +28,10 @@ dependencies {
     implementation 'org.springframework.boot:spring-boot-starter-data-redis'
     implementation 'org.springframework.boot:spring-boot-starter-validation'
 
+    // #335 — 분산 락 (RollingUpdate 시 멀티 파드 공존 중 데몬 중복 실행 차단)
+    implementation 'net.javacrumbs.shedlock:shedlock-spring:5.16.0'
+    implementation 'net.javacrumbs.shedlock:shedlock-provider-redis-spring:5.16.0'
+
     // Oracle JDBC + Security (Wallet support for Oracle ADB)
     implementation 'com.oracle.database.jdbc:ojdbc11:23.7.0.25.01'
     implementation 'com.oracle.database.security:oraclepki:23.7.0.25.01'
diff --git a/backend-java/src/main/java/com/tasteby/TastebyApplication.java b/backend-java/src/main/java/com/tasteby/TastebyApplication.java
index cc6b951..5395b5a 100644
--- a/backend-java/src/main/java/com/tasteby/TastebyApplication.java
+++ b/backend-java/src/main/java/com/tasteby/TastebyApplication.java
@@ -1,5 +1,6 @@
 package com.tasteby;
 
+import net.javacrumbs.shedlock.spring.annotation.EnableSchedulerLock;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.scheduling.annotation.EnableAsync;
@@ -8,6 +9,8 @@ import org.springframework.scheduling.annotation.EnableScheduling;
 @SpringBootApplication
 @EnableAsync
 @EnableScheduling
+// #335 — defaultLockAtMostFor: 어떤 작업이 lockAtMostFor 명시 안 해도 보호 (안전 마진)
+@EnableSchedulerLock(defaultLockAtMostFor = "PT15M")
 public class TastebyApplication {
     public static void main(String[] args) {
         SpringApplication.run(TastebyApplication.class, args);
diff --git a/backend-java/src/main/java/com/tasteby/config/ShedLockConfig.java b/backend-java/src/main/java/com/tasteby/config/ShedLockConfig.java
new file mode 100644
index 0000000..a76ceb0
--- /dev/null
+++ b/backend-java/src/main/java/com/tasteby/config/ShedLockConfig.java
@@ -0,0 +1,22 @@
+package com.tasteby.config;
+
+import net.javacrumbs.shedlock.core.LockProvider;
+import net.javacrumbs.shedlock.provider.redis.spring.RedisLockProvider;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.redis.connection.RedisConnectionFactory;
+
+/**
+ * #335 — ShedLock LockProvider (Redis 기반).
+ *
+ * 데몬 스케줄러가 다중 파드 환경에서 한 번에 하나만 실행되도록 보장.
+ * key prefix는 ShedLock 기본 ("lock:")을 사용 → Redis 키는 `lock:daemon-runner`.
+ */
+@Configuration
+public class ShedLockConfig {
+
+    @Bean
+    public LockProvider lockProvider(RedisConnectionFactory connectionFactory) {
+        return new RedisLockProvider(connectionFactory);
+    }
+}
diff --git a/backend-java/src/main/java/com/tasteby/service/DaemonScheduler.java b/backend-java/src/main/java/com/tasteby/service/DaemonScheduler.java
index 4e31d39..531b413 100644
--- a/backend-java/src/main/java/com/tasteby/service/DaemonScheduler.java
+++ b/backend-java/src/main/java/com/tasteby/service/DaemonScheduler.java
@@ -1,6 +1,7 @@
 package com.tasteby.service;
 
 import com.tasteby.domain.DaemonConfig;
+import net.javacrumbs.shedlock.spring.annotation.SchedulerLock;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Value;
@@ -37,6 +38,10 @@ public class DaemonScheduler {
     }
 
     @Scheduled(fixedDelay = 30_000) // Check every 30 seconds
+    // #335 — 분산 락: 멀티 파드 환경에서 한 인스턴스만 실행. Redis 키 `lock:daemon-runner`.
+    // lockAtMostFor: 작업이 비정상 종료돼도 15분 후 강제 해제 (다음 cron이 잡을 수 있게)
+    // lockAtLeastFor: 빨리 끝나도 30초 동안 유지 (즉시 다른 cron이 같은 작업 잡는 것 방지)
+    @SchedulerLock(name = "daemon-runner", lockAtMostFor = "PT15M", lockAtLeastFor = "PT30S")
     public void run() {
         // 인스턴스 차원 차단(dev/prod 동일 DB 공유 환경에서 dev 쪽 동시 폴링 방지).
         // dev .env: DAEMON_ENABLED=false → 이 인스턴스는 스케줄러 동작 안 함.