diff --git a/romanova_adelina_lab_3/README.md b/romanova_adelina_lab_3/README.md
new file mode 100644
index 0000000..cc971f5
--- /dev/null
+++ b/romanova_adelina_lab_3/README.md
@@ -0,0 +1,283 @@
+# Лабораторная работа №3 - REST API, Gateway и синхронный обмен между микросервисами
+
+## Задание
+
+#### Цель: 
+
+Изучение шаблона проектирования gateway, построения синхронного обмена между микросервисами и архитектурного стиля RESTful API.
+
+#### Задачи:
+
+* Создать 2 микросервиса, реализующих CRUD на связанных сущностях.
+* Реализовать механизм синхронного обмена сообщениями между микросервисами.
+* Реализовать шлюз на основе прозрачного прокси-сервера nginx.
+
+### Сервисы:
+ 1. ```product_service``` - сервис, отвечающий за продукты
+
+ 2. ```service_service``` - сервис, отвечающий за услуги, которые содержат в себе продукты
+
+#### Связь между сервисами:
+ ```service (single) <- product (many)```
+
+## Как запустить программу:
+```
+docker compose up
+```
+
+## Файловая иерархия
+
+```
+Лаба 3/
+|-- service_service/
+|   |-- Dockerfile
+|   |-- requirements.txt
+|   |-- service_service.py
+|-- product_service/
+|   |-- Dockerfile
+|   |-- requirements.txt
+|   |-- product_service.py
+|-- nginx/
+|   |-- Dockerfile
+|   |-- nginx.conf
+|-- docker-compose.yml
+```
+
+## Описание работы:
+
+Для разработки приложений был выбран язык программирования - ```python```
+
+#### Синхронный обмен сообщениями
+`product_service` будет отправлять http-запрос на `service_service` при определенных crud операциях.
+
+#### Операции CRUD для услуги
+
+Просмотр списка имеющихся услуг:
+```
+@app.route('/all', methods=['GET'])
+def show_service_ids():
+    return service_ids
+```
+
+Добавление услуги:
+```
+@app.route('/add/<string:name>', methods=['POST'])
+def create_service_id(name):
+    if request.method == 'POST':
+        if len(service_ids) == 0:
+            id = 1
+        else:
+            id = service_ids[-1]['id'] + 1
+        service_id = {'id': id, 'name': name}
+        service_ids.append(service_id)
+        return jsonify(service_id)
+```
+
+Поиск услуги по ID:
+```
+@app.route('/get/<int:id>', methods=['GET'])
+def get_service_id(id):
+    found_service = next((service_id for service_id in service_ids if service_id['id'] == id), None)
+    if found_service:
+        return jsonify(found_service)
+    else:
+        return jsonify({'error': 'service_id not found'})
+```
+
+Обновление услуги:
+```
+@app.route('/upd/<int:id>_<string:name>', methods=['PUT'])
+def update_service_id(id, name):
+    service = next((service_id for service_id in service_ids if service_id['id'] == id), None)
+    if service:
+        service['name'] = name
+        return jsonify(service)
+    else:
+        return jsonify({'error': 'service_id not found'})
+
+```
+
+Удаление услуги:
+```
+@app.route('/del/<int:id>', methods=['DELETE'])
+def delete_service_id(id):
+    global service_ids
+    service_ids = [service_id for service_id in service_ids if service_id['id'] != id]
+    return jsonify({'result': True})
+
+if __name__ == '__main__':
+    app.run(port=5001)
+
+```
+
+#### Операции CRUD для продукта
+
+Просмотр списка имеющихся продуктов:
+```
+@app.route('/all', methods=['GET'])
+def show_products():
+    return products
+```
+
+Добавление продукта:
+```
+@app.route('/add/<int:service_id>_<string:product>', methods=['POST'])
+def create_product(service_id, product):
+    product = {'id': len(products) + 1,
+             'service_id': service_id,
+             'product': product,
+             'action': 'create'}
+    products.append(product)
+    requests.post("http://service-service:5001/event", json=product)
+
+    return jsonify(product)
+```
+
+Поиск продукта по ID:
+```
+@app.route('/get/<int:product_id>', methods=['GET'])
+def get_product(product_id):
+    found_product = next((product for product in products if product['id'] == product_id), None)
+    if found_product:
+        read_product = {'id': found_product['id'],
+                        'service_id': found_product['service_id'],
+                        'product': found_product['product']}
+        return jsonify(read_product)
+    else:
+        return jsonify({'error': 'product not found'})
+```
+
+Обновление продукта:
+```
+@app.route('/upd/<int:product_id>/<string:new_product>', methods=['PUT'])
+def update_product(product_id, new_product):
+    product = next((prod for prod in products if prod['id'] == product_id), None)
+    if product:
+        product['product'] = new_product
+        product['action'] = 'update'
+        requests.post("http://service-service:5001/event", json=product)
+        return jsonify({'message': 'Product updated successfully'})
+    else:
+        return jsonify({'error': 'Product not found'})
+
+```
+
+Удаление продукта:
+```
+@app.route('/product/del_<int:product_id>', methods=['DELETE'])
+def delete_product(product_id):
+    global products
+    deleted_product = next((product for product in products if product['id'] == product_id), None)
+    products = [product for product in products if product['id'] != product_id]
+    deleted_product['action'] = 'delete'
+
+    requests.post("http://service-service:5001/event", json=deleted_product)
+
+    return jsonify({'result': True})
+
+```
+
+### Docker-compose
+
+
+Конфигурационный файл ```docker-сompose``` представляет собой многоконтейнерное приложение с тремя сервисами: ```service-service```, ```product-service``` и ```nginx```. Эти сервисы подключены к собственной сети типа "```bridge```" с именем ```my_network```
+
+```
+version: '3.8'
+
+services:
+  service-service:
+    build:
+      context: ./service_service
+    ports:
+      - "5001:5001"
+    networks:
+      - my_network
+    restart: always
+
+  product-service:
+    build:
+      context: ./product_service
+    ports:
+      - "5002:5002"
+    networks:
+      - my_network
+    restart: always
+
+  nginx:
+    image: nginx:latest
+    ports:
+      - "80:80"
+    depends_on:
+      - service-service
+      - product-service
+    networks:
+      - my_network
+    volumes:
+      - ./nginx/nginx.conf:/etc/nginx/nginx.conf
+    restart: always
+
+networks:
+  my_network:
+    driver: bridge
+```
+
+### Nginx
+
+
+Этот файл представляет собой конфигурацию для ```Nginx```, который является веб-сервером и обратным прокси:
+
+```
+events {
+    worker_connections 1024;
+}
+
+http {
+    server {
+        listen 80;
+        listen [::]:80;
+        server_name localhost;
+
+        location /service-service/ {
+            proxy_pass http://service-service:5001/;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+        }
+
+        location /product-service/ {
+            proxy_pass http://product-service:5002/;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+        }
+    }
+}
+
+```
+### Dockerfile микросервисов
+
+Dockerfile для услуг
+```
+FROM python:3.11
+WORKDIR /app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+COPY . /app
+CMD ["gunicorn", "--bind", "0.0.0.0:5001", "service_service:app"]
+```
+
+Dockerfile для продуктов
+```
+FROM python:3.11
+WORKDIR /app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+COPY . /app
+CMD ["gunicorn", "--bind", "0.0.0.0:5002", "product_service:app"]
+```
+
+# Youtube
+https://www.youtube.com/watch?v=Sf0CkkcuveY
\ No newline at end of file
diff --git a/romanova_adelina_lab_3/docker-compose.yaml b/romanova_adelina_lab_3/docker-compose.yaml
new file mode 100644
index 0000000..7dbcc78
--- /dev/null
+++ b/romanova_adelina_lab_3/docker-compose.yaml
@@ -0,0 +1,37 @@
+version: '3.8'
+
+services:
+  service-service:
+    build:
+      context: ./service_service
+    ports:
+      - "5001:5001"
+    networks:
+      - my_network
+    restart: always
+
+  product-service:
+    build:
+      context: ./product_service
+    ports:
+      - "5002:5002"
+    networks:
+      - my_network
+    restart: always
+
+  nginx:
+    image: nginx:latest
+    ports:
+      - "80:80"
+    depends_on:
+      - service-service
+      - product-service
+    networks:
+      - my_network
+    volumes:
+      - ./nginx/nginx.conf:/etc/nginx/nginx.conf
+    restart: always
+
+networks:
+  my_network:
+    driver: bridge
\ No newline at end of file
diff --git a/romanova_adelina_lab_3/nginx/Dockerfile b/romanova_adelina_lab_3/nginx/Dockerfile
new file mode 100644
index 0000000..1434a93
--- /dev/null
+++ b/romanova_adelina_lab_3/nginx/Dockerfile
@@ -0,0 +1,4 @@
+FROM nginx
+COPY nginx.conf /etc/nginx/nginx.conf
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]
diff --git a/romanova_adelina_lab_3/nginx/nginx.conf b/romanova_adelina_lab_3/nginx/nginx.conf
new file mode 100644
index 0000000..95f432b
--- /dev/null
+++ b/romanova_adelina_lab_3/nginx/nginx.conf
@@ -0,0 +1,27 @@
+events {
+    worker_connections 1024;
+}
+
+http {
+    server {
+        listen 80;
+        listen [::]:80;
+        server_name localhost;
+
+        location /service-service/ {
+            proxy_pass http://service-service:5001/;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+        }
+
+        location /product-service/ {
+            proxy_pass http://product-service:5002/;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+        }
+    }
+}
\ No newline at end of file
diff --git a/romanova_adelina_lab_3/product_service/Dockerfile b/romanova_adelina_lab_3/product_service/Dockerfile
new file mode 100644
index 0000000..397e88f
--- /dev/null
+++ b/romanova_adelina_lab_3/product_service/Dockerfile
@@ -0,0 +1,6 @@
+FROM python:3.11
+WORKDIR /app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+COPY . /app
+CMD ["gunicorn", "--bind", "0.0.0.0:5002", "product_service:app"]
\ No newline at end of file
diff --git a/romanova_adelina_lab_3/product_service/product_service.py b/romanova_adelina_lab_3/product_service/product_service.py
new file mode 100644
index 0000000..8b77316
--- /dev/null
+++ b/romanova_adelina_lab_3/product_service/product_service.py
@@ -0,0 +1,60 @@
+# product_service.py
+from flask import Flask, request, jsonify
+import requests
+
+app = Flask(__name__)
+
+products = []
+
+@app.route('/all', methods=['GET'])
+def show_products():
+    return products
+
+@app.route('/add/<int:service_id>_<string:product>', methods=['POST'])
+def create_product(service_id, product):
+    product = {'id': len(products) + 1,
+             'service_id': service_id,
+             'product': product,
+             'action': 'create'}
+    products.append(product)
+    requests.post("http://service-service:5001/event", json=product)
+
+    return jsonify(product)
+
+@app.route('/upd/<int:product_id>/<string:new_product>', methods=['PUT'])
+def update_product(product_id, new_product):
+    product = next((prod for prod in products if prod['id'] == product_id), None)
+    if product:
+        product['product'] = new_product
+        product['action'] = 'update'
+        requests.post("http://service-service:5001/event", json=product)
+        return jsonify({'message': 'Product updated successfully'})
+    else:
+        return jsonify({'error': 'Product not found'})
+
+@app.route('/get/<int:product_id>', methods=['GET'])
+def get_product(product_id):
+    found_product = next((product for product in products if product['id'] == product_id), None)
+    if found_product:
+        read_product = {'id': found_product['id'],
+                        'service_id': found_product['service_id'],
+                        'product': found_product['product']}
+        return jsonify(read_product)
+    else:
+        return jsonify({'error': 'product not found'})
+
+@app.route('/product/del_<int:product_id>', methods=['DELETE'])
+def delete_product(product_id):
+    global products
+    deleted_product = next((product for product in products if product['id'] == product_id), None)
+    products = [product for product in products if product['id'] != product_id]
+    deleted_product['action'] = 'delete'
+
+    requests.post("http://service-service:5001/event", json=deleted_product)
+
+    return jsonify({'result': True})
+
+
+
+if __name__ == '__main__':
+    app.run(port=5002)
diff --git a/romanova_adelina_lab_3/product_service/requirements.txt b/romanova_adelina_lab_3/product_service/requirements.txt
new file mode 100644
index 0000000..3d70f32
--- /dev/null
+++ b/romanova_adelina_lab_3/product_service/requirements.txt
@@ -0,0 +1,3 @@
+Flask==3.0.0
+requests==2.31.0
+gunicorn==21.2.0
\ No newline at end of file
diff --git a/romanova_adelina_lab_3/service_service/Dockerfile b/romanova_adelina_lab_3/service_service/Dockerfile
new file mode 100644
index 0000000..a7fdbdd
--- /dev/null
+++ b/romanova_adelina_lab_3/service_service/Dockerfile
@@ -0,0 +1,6 @@
+FROM python:3.11
+WORKDIR /app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+COPY . /app
+CMD ["gunicorn", "--bind", "0.0.0.0:5001", "service_service:app"]
\ No newline at end of file
diff --git a/romanova_adelina_lab_3/service_service/requirements.txt b/romanova_adelina_lab_3/service_service/requirements.txt
new file mode 100644
index 0000000..3d70f32
--- /dev/null
+++ b/romanova_adelina_lab_3/service_service/requirements.txt
@@ -0,0 +1,3 @@
+Flask==3.0.0
+requests==2.31.0
+gunicorn==21.2.0
\ No newline at end of file
diff --git a/romanova_adelina_lab_3/service_service/service_service.py b/romanova_adelina_lab_3/service_service/service_service.py
new file mode 100644
index 0000000..4d90a23
--- /dev/null
+++ b/romanova_adelina_lab_3/service_service/service_service.py
@@ -0,0 +1,87 @@
+# service_id_service.py
+import json
+import time
+from flask import Flask, request, jsonify
+
+app = Flask(__name__)
+service_ids = []
+
+@app.route('/event', methods=['POST'])
+def event():
+    data = request.get_json()
+    print(data)
+    input_service_id = data.get('service_id')
+
+    if data['action'] == 'create':
+        service = next((service_id for service_id in service_ids if service_id['id'] == input_service_id), None)
+        if service:
+            product_id = len(service.get('products', [])) + 1
+            product = {'id': product_id, 'product': data['product']}
+            service.setdefault('products', []).append(product)
+            print(f"Product created for service_id {input_service_id}: {product}")
+        else:
+            print(f"service_id not found for product creation: {input_service_id}")
+
+    elif data['action'] == 'update':
+        service = next((service_id for service_id in service_ids if service_id['id'] == input_service_id), None)
+        if service:
+            product_id = data.get('id')
+            product = next((product for product in service['products'] if product['id'] == product_id), None)
+            if product:
+                product['product'] = data['product']
+                print(f"Product updated for service_id {input_service_id}: {product}")
+            else:
+                print(f"Product not found for update: {product_id}")
+        else:
+            print(f"service_id not found for product update: {input_service_id}")
+
+    elif data['action'] == 'delete':
+        service = next((service_id for service_id in service_ids if service_id['id'] == input_service_id), None)
+        if service:
+            product_id = service.get('id')
+            service['products'] = [product for product in service.get('products', []) if product['id'] != product_id]
+            print(f"Product deleted for service_id {input_service_id}: {product_id}")
+        else:
+            print(f"service_id not found for product deletion: {input_service_id}")
+    return jsonify({'result': True})
+
+@app.route('/all', methods=['GET'])
+def show_service_ids():
+    return service_ids
+
+@app.route('/add/<string:name>', methods=['POST'])
+def create_service_id(name):
+    if request.method == 'POST':
+        if len(service_ids) == 0:
+            id = 1
+        else:
+            id = service_ids[-1]['id'] + 1
+        service_id = {'id': id, 'name': name}
+        service_ids.append(service_id)
+        return jsonify(service_id)
+
+@app.route('/get/<int:id>', methods=['GET'])
+def get_service_id(id):
+    found_service = next((service_id for service_id in service_ids if service_id['id'] == id), None)
+    if found_service:
+        return jsonify(found_service)
+    else:
+        return jsonify({'error': 'service_id not found'})
+
+@app.route('/upd/<int:id>_<string:name>', methods=['PUT'])
+def update_service_id(id, name):
+    service = next((service_id for service_id in service_ids if service_id['id'] == id), None)
+    if service:
+        service['name'] = name
+        return jsonify(service)
+    else:
+        return jsonify({'error': 'service_id not found'})
+
+@app.route('/del/<int:id>', methods=['DELETE'])
+def delete_service_id(id):
+    global service_ids
+    service_ids = [service_id for service_id in service_ids if service_id['id'] != id]
+    return jsonify({'result': True})
+
+if __name__ == '__main__':
+    app.run(port=5001)