diff --git a/main.py b/main.py
index 8eb9bb8..8068372 100644
--- a/main.py
+++ b/main.py
@@ -1,24 +1,115 @@
-from flask import Flask
+from flask import Flask, request
+from prometheus_client import (
+    CollectorRegistry,
+    generate_latest,
+    CONTENT_TYPE_LATEST,
+    Counter,
+    Gauge,
+    Histogram,
+    disable_created_metrics,
+)
 from dotenv import load_dotenv
 import os
+import time
+import random
+import requests
+from prometheus_summary import Summary
 
 load_dotenv()
 
+disable_created_metrics()
+
 app = Flask(__name__)
 
-@app.route('/metrics')
+# Create a custom registry
+registry = CollectorRegistry()
+
+# Create a counter metric
+http_requests_total = Counter(
+    "http_requests_total",
+    "Total number of HTTP requests received",
+    ["status", "path", "method"],
+    registry=registry,
+)
+
+# Define a Gauge metric for tracking active HTTP requests
+active_requests_gauge = Gauge(
+    "http_active_requests",
+    "Number of active connections to the service",
+    registry=registry,
+)
+
+# Define a Histogram metric for request duration
+latency_histogram = Histogram(
+    "http_request_duration_seconds",
+    "Duration of HTTP requests",
+    ["status", "path", "method"],
+    registry=registry,
+)
+
+posts_latency_summary = Summary(
+    "post_request_duration_seconds",
+    "Duration of requests to https://jsonplaceholder.typicode.com/posts",
+    ["method"],
+    registry=registry,
+)
+
+
+@app.before_request
+def before_request():
+    delay = random.uniform(0.5, 2)
+    time.sleep(delay)
+    """Track start of request processing"""
+    active_requests_gauge.inc()
+    request.start_time = time.time()
+
+
+@app.after_request
+def after_request(response):
+    """Increment counter after each request"""
+    http_requests_total.labels(
+        status=str(response.status_code), path=request.path, method=request.method
+    ).inc()
+    active_requests_gauge.dec()
+    duration = time.time() - request.start_time
+    latency_histogram.labels(
+        status=str(response.status_code), path=request.path, method=request.method
+    ).observe(duration)
+    return response
+
+
+@app.route("/posts")
+def get_posts():
+    start_time = time.time()
+
+    try:
+        response = requests.get("https://jsonplaceholder.typicode.com/posts")
+        response.raise_for_status()
+    except requests.RequestException as e:
+        return str(e), 500
+    finally:
+        # Record the request duration in the summary
+        duration = time.time() - start_time
+        posts_latency_summary.labels(method="GET").observe(duration)
+
+    return response.json()
+
+
+@app.route("/metrics")
 def metrics():
-    return '', 200
+    return generate_latest(registry), 200, {"Content-Type": CONTENT_TYPE_LATEST}
 
-@app.route('/')
+
+@app.route("/")
 def hello():
-    return 'Hello world!'
+    return "Hello world!"
+
 
-if __name__ == '__main__':
-    port = int(os.getenv('PORT', '8000'))
-    print(f'Starting HTTP server on port {port}')
+if __name__ == "__main__":
+    port = int(os.getenv("PORT", "8000"))
+    print(f"Starting HTTP server on port {port}")
     try:
-        app.run(host='0.0.0.0', port=port, debug=True)
+        app.run(host="0.0.0.0", port=port, debug=True)
     except Exception as e:
-        print(f'Server failed to start: {e}')
+        print(f"Server failed to start: {e}")
         exit(1)
diff --git a/requirements.txt b/requirements.txt
index c1a79a7..20343bb 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,5 @@
 Flask==3.1.0
 python-dotenv==1.0.1
+prometheus_client
+requests
+prometheus-summary