diff --git a/deployment/container/nginx.conf b/deployment/container/nginx.conf
index 500b3c3..fbd7130 100644
--- a/deployment/container/nginx.conf
+++ b/deployment/container/nginx.conf
@@ -23,6 +23,10 @@ http {
     keepalive_timeout 65;
     types_hash_max_size 2048;
 
+    # 헤더 및 쿠키 버퍼 크기 증가
+    large_client_header_buffers 4 32k;
+    client_header_buffer_size 32k;
+
     gzip on;
     gzip_vary on;
     gzip_proxied any;
@@ -59,6 +63,11 @@ http {
             proxy_connect_timeout 180s;
             proxy_send_timeout 180s;
             proxy_read_timeout 180s;
+
+            # 프록시 버퍼 크기 증가
+            proxy_buffer_size 32k;
+            proxy_buffers 4 32k;
+            proxy_busy_buffers_size 64k;
         }
 
         # Static files
diff --git a/next.config.js b/next.config.js
index fcfa97a..69c915f 100644
--- a/next.config.js
+++ b/next.config.js
@@ -25,11 +25,6 @@ const nextConfig = {
         source: '/api/v1/events/:path*',
         destination: 'http://localhost:8080/api/v1/events/:path*',
       },
-      // Participation Service API Proxy (외부 서버)
-      {
-        source: '/api/v1/participations/:path*',
-        destination: 'http://kt-event-marketing-api.20.214.196.128.nip.io/api/v1/participations/:path*',
-      },
     ]
   },
 }
diff --git a/src/app/api/v1/events/[eventId]/draw-winners/route.ts b/src/app/api/v1/events/[eventId]/draw-winners/route.ts
new file mode 100644
index 0000000..ef0b3c7
--- /dev/null
+++ b/src/app/api/v1/events/[eventId]/draw-winners/route.ts
@@ -0,0 +1,47 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+const PARTICIPATION_API_BASE_URL = 'http://kt-event-marketing-api.20.214.196.128.nip.io';
+
+export async function POST(
+  request: NextRequest,
+  { params }: { params: { eventId: string } }
+) {
+  try {
+    const { eventId } = params;
+    const body = await request.json();
+
+    console.log('🔄 Proxying draw winners request to Participation API:', {
+      url: `${PARTICIPATION_API_BASE_URL}/api/v1/participations/api/v1/events/${eventId}/draw-winners`,
+      eventId,
+      body,
+    });
+
+    const response = await fetch(`${PARTICIPATION_API_BASE_URL}/api/v1/participations/api/v1/events/${eventId}/draw-winners`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify(body),
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      console.error('❌ Participation API error:', response.status, errorText);
+      return NextResponse.json(
+        { error: 'Failed to draw winners', details: errorText },
+        { status: response.status }
+      );
+    }
+
+    const data = await response.json();
+    console.log('✅ Winners drawn:', data);
+
+    return NextResponse.json(data);
+  } catch (error) {
+    console.error('❌ Proxy error:', error);
+    return NextResponse.json(
+      { error: 'Internal server error', details: error instanceof Error ? error.message : 'Unknown error' },
+      { status: 500 }
+    );
+  }
+}
diff --git a/src/app/api/v1/events/[eventId]/participants/[participantId]/route.ts b/src/app/api/v1/events/[eventId]/participants/[participantId]/route.ts
new file mode 100644
index 0000000..98d0a24
--- /dev/null
+++ b/src/app/api/v1/events/[eventId]/participants/[participantId]/route.ts
@@ -0,0 +1,48 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+const PARTICIPATION_API_BASE_URL = 'http://kt-event-marketing-api.20.214.196.128.nip.io';
+
+export async function GET(
+  request: NextRequest,
+  { params }: { params: { eventId: string; participantId: string } }
+) {
+  try {
+    const { eventId, participantId } = params;
+
+    console.log('🔄 Proxying get participant request to Participation API:', {
+      url: `${PARTICIPATION_API_BASE_URL}/api/v1/participations/api/v1/events/${eventId}/participants/${participantId}`,
+      eventId,
+      participantId,
+    });
+
+    const response = await fetch(
+      `${PARTICIPATION_API_BASE_URL}/api/v1/participations/api/v1/events/${eventId}/participants/${participantId}`,
+      {
+        method: 'GET',
+        headers: {
+          'Content-Type': 'application/json',
+        },
+      }
+    );
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      console.error('❌ Participation API error:', response.status, errorText);
+      return NextResponse.json(
+        { error: 'Failed to get participant', details: errorText },
+        { status: response.status }
+      );
+    }
+
+    const data = await response.json();
+    console.log('✅ Participant retrieved:', data);
+
+    return NextResponse.json(data);
+  } catch (error) {
+    console.error('❌ Proxy error:', error);
+    return NextResponse.json(
+      { error: 'Internal server error', details: error instanceof Error ? error.message : 'Unknown error' },
+      { status: 500 }
+    );
+  }
+}
diff --git a/src/app/api/v1/events/[eventId]/participants/route.ts b/src/app/api/v1/events/[eventId]/participants/route.ts
new file mode 100644
index 0000000..8040343
--- /dev/null
+++ b/src/app/api/v1/events/[eventId]/participants/route.ts
@@ -0,0 +1,61 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+const PARTICIPATION_API_BASE_URL = 'http://kt-event-marketing-api.20.214.196.128.nip.io';
+
+export async function GET(
+  request: NextRequest,
+  { params }: { params: { eventId: string } }
+) {
+  try {
+    const { eventId } = params;
+    const { searchParams } = new URL(request.url);
+
+    // Extract query parameters
+    const storeVisited = searchParams.get('storeVisited');
+    const page = searchParams.get('page') || '0';
+    const size = searchParams.get('size') || '20';
+    const sort = searchParams.getAll('sort');
+
+    // Build query string
+    const queryParams = new URLSearchParams();
+    if (storeVisited !== null) queryParams.append('storeVisited', storeVisited);
+    queryParams.append('page', page);
+    queryParams.append('size', size);
+    sort.forEach(s => queryParams.append('sort', s));
+
+    const url = `${PARTICIPATION_API_BASE_URL}/api/v1/participations/api/v1/events/${eventId}/participants?${queryParams.toString()}`;
+
+    console.log('🔄 Proxying participants list request to Participation API:', {
+      url,
+      eventId,
+      params: { storeVisited, page, size, sort },
+    });
+
+    const response = await fetch(url, {
+      method: 'GET',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      console.error('❌ Participation API error:', response.status, errorText);
+      return NextResponse.json(
+        { error: 'Failed to get participants', details: errorText },
+        { status: response.status }
+      );
+    }
+
+    const data = await response.json();
+    console.log('✅ Participants retrieved:', data);
+
+    return NextResponse.json(data);
+  } catch (error) {
+    console.error('❌ Proxy error:', error);
+    return NextResponse.json(
+      { error: 'Internal server error', details: error instanceof Error ? error.message : 'Unknown error' },
+      { status: 500 }
+    );
+  }
+}
diff --git a/src/app/api/v1/events/[eventId]/participate/route.ts b/src/app/api/v1/events/[eventId]/participate/route.ts
new file mode 100644
index 0000000..f03c08b
--- /dev/null
+++ b/src/app/api/v1/events/[eventId]/participate/route.ts
@@ -0,0 +1,47 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+const PARTICIPATION_API_BASE_URL = 'http://kt-event-marketing-api.20.214.196.128.nip.io';
+
+export async function POST(
+  request: NextRequest,
+  { params }: { params: { eventId: string } }
+) {
+  try {
+    const { eventId } = params;
+    const body = await request.json();
+
+    console.log('🔄 Proxying participation request to Participation API:', {
+      url: `${PARTICIPATION_API_BASE_URL}/api/v1/participations/api/v1/events/${eventId}/participate`,
+      eventId,
+      body,
+    });
+
+    const response = await fetch(`${PARTICIPATION_API_BASE_URL}/api/v1/participations/api/v1/events/${eventId}/participate`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify(body),
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      console.error('❌ Participation API error:', response.status, errorText);
+      return NextResponse.json(
+        { error: 'Failed to participate in event', details: errorText },
+        { status: response.status }
+      );
+    }
+
+    const data = await response.json();
+    console.log('✅ Participation created:', data);
+
+    return NextResponse.json(data);
+  } catch (error) {
+    console.error('❌ Proxy error:', error);
+    return NextResponse.json(
+      { error: 'Internal server error', details: error instanceof Error ? error.message : 'Unknown error' },
+      { status: 500 }
+    );
+  }
+}
diff --git a/src/app/api/v1/events/[eventId]/winners/route.ts b/src/app/api/v1/events/[eventId]/winners/route.ts
new file mode 100644
index 0000000..1899f0b
--- /dev/null
+++ b/src/app/api/v1/events/[eventId]/winners/route.ts
@@ -0,0 +1,59 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+const PARTICIPATION_API_BASE_URL = 'http://kt-event-marketing-api.20.214.196.128.nip.io';
+
+export async function GET(
+  request: NextRequest,
+  { params }: { params: { eventId: string } }
+) {
+  try {
+    const { eventId } = params;
+    const { searchParams } = new URL(request.url);
+
+    // Extract query parameters
+    const page = searchParams.get('page') || '0';
+    const size = searchParams.get('size') || '20';
+    const sort = searchParams.getAll('sort');
+
+    // Build query string
+    const queryParams = new URLSearchParams();
+    queryParams.append('page', page);
+    queryParams.append('size', size);
+    sort.forEach(s => queryParams.append('sort', s));
+
+    const url = `${PARTICIPATION_API_BASE_URL}/api/v1/participations/api/v1/events/${eventId}/winners?${queryParams.toString()}`;
+
+    console.log('🔄 Proxying winners list request to Participation API:', {
+      url,
+      eventId,
+      params: { page, size, sort },
+    });
+
+    const response = await fetch(url, {
+      method: 'GET',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      console.error('❌ Participation API error:', response.status, errorText);
+      return NextResponse.json(
+        { error: 'Failed to get winners', details: errorText },
+        { status: response.status }
+      );
+    }
+
+    const data = await response.json();
+    console.log('✅ Winners retrieved:', data);
+
+    return NextResponse.json(data);
+  } catch (error) {
+    console.error('❌ Proxy error:', error);
+    return NextResponse.json(
+      { error: 'Internal server error', details: error instanceof Error ? error.message : 'Unknown error' },
+      { status: 500 }
+    );
+  }
+}
diff --git a/src/shared/api/participation.api.ts b/src/shared/api/participation.api.ts
index 3eeb37b..931bc19 100644
--- a/src/shared/api/participation.api.ts
+++ b/src/shared/api/participation.api.ts
@@ -1,4 +1,4 @@
-import { participationClient } from './client';
+import axios from 'axios';
 import type {
   ApiResponse,
   PageResponse,
@@ -10,18 +10,19 @@ import type {
 /**
  * Participation API Service
  * 이벤트 참여 관련 API 함수들
+ * Next.js API Routes를 통해 프록시하여 CORS 문제 해결
  */
 
 /**
  * 이벤트 참여 신청
- * POST /v1/events/{eventId}/participate
+ * POST /api/v1/events/{eventId}/participate
  */
 export const participate = async (
   eventId: string,
   data: ParticipationRequest
 ): Promise<ApiResponse<ParticipationResponse>> => {
-  const response = await participationClient.post<ApiResponse<ParticipationResponse>>(
-    `/v1/events/${eventId}/participate`,
+  const response = await axios.post<ApiResponse<ParticipationResponse>>(
+    `/api/v1/events/${eventId}/participate`,
     data
   );
   return response.data;
@@ -29,15 +30,15 @@ export const participate = async (
 
 /**
  * 참여자 목록 조회 (페이징)
- * GET /v1/events/{eventId}/participants
+ * GET /api/v1/events/{eventId}/participants
  */
 export const getParticipants = async (
   params: GetParticipantsParams
 ): Promise<ApiResponse<PageResponse<ParticipationResponse>>> => {
   const { eventId, storeVisited, page = 0, size = 20, sort = ['createdAt,DESC'] } = params;
 
-  const response = await participationClient.get<ApiResponse<PageResponse<ParticipationResponse>>>(
-    `/v1/events/${eventId}/participants`,
+  const response = await axios.get<ApiResponse<PageResponse<ParticipationResponse>>>(
+    `/api/v1/events/${eventId}/participants`,
     {
       params: {
         storeVisited,
@@ -52,14 +53,14 @@ export const getParticipants = async (
 
 /**
  * 특정 참여자 정보 조회
- * GET /v1/events/{eventId}/participants/{participantId}
+ * GET /api/v1/events/{eventId}/participants/{participantId}
  */
 export const getParticipant = async (
   eventId: string,
   participantId: string
 ): Promise<ApiResponse<ParticipationResponse>> => {
-  const response = await participationClient.get<ApiResponse<ParticipationResponse>>(
-    `/v1/events/${eventId}/participants/${participantId}`
+  const response = await axios.get<ApiResponse<ParticipationResponse>>(
+    `/api/v1/events/${eventId}/participants/${participantId}`
   );
   return response.data;
 };
@@ -112,15 +113,15 @@ export const searchParticipants = async (
 
 /**
  * 당첨자 추첨
- * POST /v1/events/{eventId}/draw-winners
+ * POST /api/v1/events/{eventId}/draw-winners
  */
 export const drawWinners = async (
   eventId: string,
   winnerCount: number,
   applyStoreVisitBonus?: boolean
 ): Promise<ApiResponse<import('../types/api.types').DrawWinnersResponse>> => {
-  const response = await participationClient.post<ApiResponse<import('../types/api.types').DrawWinnersResponse>>(
-    `/v1/events/${eventId}/draw-winners`,
+  const response = await axios.post<ApiResponse<import('../types/api.types').DrawWinnersResponse>>(
+    `/api/v1/events/${eventId}/draw-winners`,
     {
       winnerCount,
       applyStoreVisitBonus,
@@ -131,7 +132,7 @@ export const drawWinners = async (
 
 /**
  * 당첨자 목록 조회
- * GET /v1/events/{eventId}/winners
+ * GET /api/v1/events/{eventId}/winners
  */
 export const getWinners = async (
   eventId: string,
@@ -139,8 +140,8 @@ export const getWinners = async (
   size = 20,
   sort: string[] = ['winnerRank,ASC']
 ): Promise<ApiResponse<PageResponse<ParticipationResponse>>> => {
-  const response = await participationClient.get<ApiResponse<PageResponse<ParticipationResponse>>>(
-    `/v1/events/${eventId}/winners`,
+  const response = await axios.get<ApiResponse<PageResponse<ParticipationResponse>>>(
+    `/api/v1/events/${eventId}/winners`,
     {
       params: {
         page,