diff --git a/src/main/java/com/rainbowletter/server/petinitiatedletter/adapter/out/infrastructure/PetInitiatedLetterGenerator.java b/src/main/java/com/rainbowletter/server/petinitiatedletter/adapter/out/infrastructure/PetInitiatedLetterGenerator.java
index 6b3c990..bd4ade2 100644
--- a/src/main/java/com/rainbowletter/server/petinitiatedletter/adapter/out/infrastructure/PetInitiatedLetterGenerator.java
+++ b/src/main/java/com/rainbowletter/server/petinitiatedletter/adapter/out/infrastructure/PetInitiatedLetterGenerator.java
@@ -27,16 +27,15 @@ public class PetInitiatedLetterGenerator {
     public GeneratedLetterContent generate(Pet pet) {
         final AiSetting aiSetting = loadSettingPort.loadPetInitiatedLetterSetting();
         Pet.PetId petId = pet.getId();
-        log.info("[편지 작성 메소드 호출] petId={}", petId);
+        long threadId = Thread.currentThread().getId();
+
+        log.info("[편지 작성 메소드 호출] petId={}, threadId={}", petId, threadId);
 
         if (Boolean.TRUE.equals(aiSetting.getUseABTest())) {
             final Map<PromptType, String> results = new EnumMap<>(PromptType.class);
 
             for (AiPrompt prompt : aiSetting.getPrompts()) {
-                String content = callAiClientPort.call(new AiClientCommand(prompt, List.of(pet)))
-                    .getResult()
-                    .getOutput()
-                    .getContent();
+                String content = callAiWithLogging(prompt, pet, petId, threadId);
                 results.put(prompt.getType(), content);
             }
 
@@ -56,13 +55,8 @@ public GeneratedLetterContent generate(Pet pet) {
         } else {
             AiPrompt selectedPrompt = aiSetting.getSelectedPrompt();
 
-            log.info("[callAiClientPort.call 메소드 호출] petId={}", petId);
-            String content = callAiClientPort.call(new AiClientCommand(selectedPrompt, List.of(pet)))
-                .getResult()
-                .getOutput()
-                .getContent();
+            String content = callAiWithLogging(selectedPrompt, pet, petId, threadId);
 
-            log.info("[callAiClientPort.call 메소드 호출 종료] petId={}", petId);
             return new GeneratedLetterContent(
                 content.substring(0, 20),
                 content,
@@ -72,4 +66,21 @@ public GeneratedLetterContent generate(Pet pet) {
             );
         }
     }
+
+    private String callAiWithLogging(AiPrompt prompt, Pet pet, Pet.PetId petId, long threadId) {
+        long start = System.currentTimeMillis();
+        log.info("[OpenAI 호출 시작] petId={}, threadId={}, promptType={}, timestamp={}",
+            petId, threadId, prompt.getType(), start);
+
+        String content = callAiClientPort.call(new AiClientCommand(prompt, List.of(pet)))
+            .getResult()
+            .getOutput()
+            .getContent();
+
+        long end = System.currentTimeMillis();
+        log.info("[OpenAI 응답 완료] petId={}, threadId={}, promptType={}, duration={}ms",
+            petId, threadId, prompt.getType(), (end - start));
+
+        return content;
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/com/rainbowletter/server/petinitiatedletter/application/domain/service/GeneratePetInitiatedLetterEventHandler.java b/src/main/java/com/rainbowletter/server/petinitiatedletter/application/domain/service/GeneratePetInitiatedLetterEventHandler.java
index 4a6c360..7dd94c0 100644
--- a/src/main/java/com/rainbowletter/server/petinitiatedletter/application/domain/service/GeneratePetInitiatedLetterEventHandler.java
+++ b/src/main/java/com/rainbowletter/server/petinitiatedletter/application/domain/service/GeneratePetInitiatedLetterEventHandler.java
@@ -13,8 +13,6 @@
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
-import org.springframework.transaction.annotation.Propagation;
-import org.springframework.transaction.annotation.Transactional;
 import org.springframework.transaction.event.TransactionPhase;
 import org.springframework.transaction.event.TransactionalEventListener;
 
@@ -29,8 +27,9 @@ public class GeneratePetInitiatedLetterEventHandler {
     private final SlackErrorReportService slackErrorReportService;
 
     @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
-    @Transactional(propagation = Propagation.REQUIRES_NEW)
     public void handleGeneratePetInitiatedLetters(GeneratePetInitiatedLetterEvent event) {
+        log.info("[이벤트 핸들러 시작] threadId={}, eventSize={}", Thread.currentThread().getId(), event.letterIds().size());
+
         for (Long letterId : event.letterIds()) {
             PetInitiatedLetter letter = petInitiatedLetterJpaRepository.findById(letterId)
                 .orElseThrow(() -> new RainbowLetterException("선편지를 찾을 수 없습니다: " + letterId));
@@ -43,6 +42,15 @@ public void handleGeneratePetInitiatedLetters(GeneratePetInitiatedLetterEvent ev
                 GeneratedLetterContent generatedLetterContent = petInitiatedLetterGenerator.generate(pet);
                 letter.generate(generatedLetterContent);
 
+                // 각 편지 요청 간 3초 딜레이
+                try {
+                    log.info("[딜레이 시작] petId={}, threadId={}, sleep=3000ms", letter.getPetId(), Thread.currentThread().getId());
+                    Thread.sleep(3000);
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                    log.warn("[딜레이 중단됨] petId={}, threadId={}", letter.getPetId(), Thread.currentThread().getId());
+                }
+
             } catch (Exception e) {
                 letter.markAsFailed();
                 log.error("선편지 AI 생성 실패, letterId={}", letter.getId(), e);