diff --git a/src/main/java/org/ktc2/cokaen/wouldyouin/advertisement/api/dto/AdvertisementRequest.java b/src/main/java/org/ktc2/cokaen/wouldyouin/advertisement/api/dto/AdvertisementRequest.java
index 566ada93..27f58443 100644
--- a/src/main/java/org/ktc2/cokaen/wouldyouin/advertisement/api/dto/AdvertisementRequest.java
+++ b/src/main/java/org/ktc2/cokaen/wouldyouin/advertisement/api/dto/AdvertisementRequest.java
@@ -30,7 +30,7 @@ public class AdvertisementRequest {
     private LocalDateTime endTime;
 
     @AssertTrue(message = "종료 시간은 시작 시간 이후여야 합니다.")
-    public boolean isEndTimeAfterStartTime() {
+    private boolean isEndTimeAfterStartTime() {
         return endTime.isAfter(startTime);
     }
 
diff --git a/src/main/java/org/ktc2/cokaen/wouldyouin/event/api/dto/EventCreateRequest.java b/src/main/java/org/ktc2/cokaen/wouldyouin/event/api/dto/EventCreateRequest.java
index 3d877b03..d236ed3d 100644
--- a/src/main/java/org/ktc2/cokaen/wouldyouin/event/api/dto/EventCreateRequest.java
+++ b/src/main/java/org/ktc2/cokaen/wouldyouin/event/api/dto/EventCreateRequest.java
@@ -66,7 +66,7 @@ public class EventCreateRequest {
     private List<Long> imageIds;
 
     @AssertTrue(message = "종료 시간은 시작 시간 이후여야 합니다.")
-    public boolean isEndTimeAfterStartTime() {
+    private boolean isEndTimeAfterStartTime() {
         if (startTime == null || endTime == null) {
             return true;
         }
@@ -74,7 +74,7 @@ public boolean isEndTimeAfterStartTime() {
     }
 
     @AssertTrue(message = "이미지는 최대 5개까지 등록할 수 있습니다.")
-    public boolean isImageSizeValid() {
+    private boolean isImageSizeValid() {
         return imageIds.size() <= 5;
     }
 
diff --git a/src/main/java/org/ktc2/cokaen/wouldyouin/event/api/dto/EventEditRequest.java b/src/main/java/org/ktc2/cokaen/wouldyouin/event/api/dto/EventEditRequest.java
index afec07f6..f06e9eab 100644
--- a/src/main/java/org/ktc2/cokaen/wouldyouin/event/api/dto/EventEditRequest.java
+++ b/src/main/java/org/ktc2/cokaen/wouldyouin/event/api/dto/EventEditRequest.java
@@ -62,7 +62,7 @@ public class EventEditRequest {
     private List<Long> imageIds;
 
     @AssertTrue(message = "종료 시간은 시작 시간 이후여야 합니다.")
-    public boolean isEndTimeAfterStartTime() {
+    private boolean isEndTimeAfterStartTime() {
         if (startTime == null || endTime == null) {
             return true;
         }
@@ -70,7 +70,7 @@ public boolean isEndTimeAfterStartTime() {
     }
 
     @AssertTrue(message = "이미지는 최대 5개까지 등록할 수 있습니다.")
-    public boolean isImageSizeValid() {
+    private boolean isImageSizeValid() {
         return imageIds.size() <= 5;
     }
 }
\ No newline at end of file
diff --git a/src/main/java/org/ktc2/cokaen/wouldyouin/review/application/ReviewService.java b/src/main/java/org/ktc2/cokaen/wouldyouin/review/application/ReviewService.java
index c2178751..f542eced 100644
--- a/src/main/java/org/ktc2/cokaen/wouldyouin/review/application/ReviewService.java
+++ b/src/main/java/org/ktc2/cokaen/wouldyouin/review/application/ReviewService.java
@@ -59,7 +59,7 @@ private Long getLastId(Slice<Review> reviews, Long oldLastId) {
         return oldLastId;
     }
 
-    @Transactional
+    @Transactional(readOnly = true)
     public ReviewEventSliceResponse getUnreviewedEventsByMemberId(Long memberId, Pageable pageable,
         Long beforeLastId) {
         Slice<Event> unreviewedEvents = reviewRepository.findUnreviewedEventsByMemberId(memberId,
@@ -95,8 +95,7 @@ public void delete(Long memberId, Long reviewId) {
         reviewRepository.deleteById(reviewId);
     }
 
-    @Transactional
-    public Review getByIdOrThrow(Long id) {
+    private Review getByIdOrThrow(Long id) {
         return reviewRepository.findById(id)
             .orElseThrow(() -> new EntityNotFoundException("해당하는 리뷰를 찾을 수 없습니다."));
     }