Top 20 Scenario-Based Python Interview Programs Every Engineer Should Know

Python interviews are no longer about reversing strings and checking palindromes. Modern interviews focus on solving real-world engineering problems.

Here are 20 scenario-based Python programs commonly asked in interviews for DevOps, Cloud, SRE, Platform Engineering, Data Engineering, and Backend roles.

1. Read a Large Log File Efficiently

Scenario: Process a 10GB application log without loading it into memory.

with open("app.log") as f:
    for line in f:
        if "ERROR" in line:
            print(line.strip())

2. Count Occurrences of IP Addresses in Logs

Scenario: Find the most frequent IPs accessing your application.

from collections import Counter

ips = ["10.0.0.1", "10.0.0.2", "10.0.0.1"]
print(Counter(ips).most_common(5))

3. Remove Duplicate Records

Scenario: Clean duplicate user IDs from a dataset.

users = [101, 102, 103, 101, 104]
unique_users = list(set(users))
print(unique_users)

4. Find Top N Largest Values

Scenario: Identify top CPU-consuming servers.

import heapq

cpu = [20, 45, 12, 80, 60]
print(heapq.nlargest(3, cpu))

5. Parse JSON API Response

Scenario: Read data from a REST API.

import json

data = '{"name":"Sachin","role":"DevOps"}'
result = json.loads(data)

print(result["name"])

6. Check Service Health Endpoint

Scenario: Verify if an application is healthy.

import requests

response = requests.get("https://example.com/health")

print(response.status_code == 200)

7. Retry Failed API Calls

Scenario: Handle temporary network failures.

import time
import requests

for attempt in range(3):
    try:
        r = requests.get("https://api.example.com")
        print(r.status_code)
        break
    except Exception:
        time.sleep(2)

8. Monitor Disk Usage

Scenario: Alert when disk usage exceeds threshold.

import shutil

usage = shutil.disk_usage("/")

print(f"Used: {usage.used // (1024**3)} GB")

9. Read Environment Variables

Scenario: Load application configuration securely.

import os

db_host = os.getenv("DB_HOST")
print(db_host)


10. Find Duplicate Files

Scenario: Detect duplicate backups.

import hashlib

def checksum(file):
    with open(file, "rb") as f:
        return hashlib.md5(f.read()).hexdigest()


11. Generate Random Password

Scenario: Create temporary credentials.

import secrets
import string

password = ''.join(
    secrets.choice(string.ascii_letters + string.digits)
    for _ in range(12)
)

print(password)


12. Validate Email Address

Scenario: Verify user input.

import re

email = "user@example.com"

print(bool(re.match(r'^[^@]+@[^@]+\.[^@]+$', email)))


13. Calculate API Response Time

Scenario: Measure service latency.

import time
import requests

start = time.time()

requests.get("https://google.com")

print(time.time() - start)


14. Concurrent API Calls

Scenario: Fetch data from multiple services simultaneously.

from concurrent.futures import ThreadPoolExecutor
import requests

urls = ["https://google.com", "https://github.com"]

with ThreadPoolExecutor() as executor:
    results = executor.map(requests.get, urls)

for r in results:
    print(r.status_code)


15. Find Most Frequent Error Message

Scenario: Analyze application logs.

from collections import Counter

errors = ["DB Error", "Timeout", "DB Error"]

print(Counter(errors).most_common(1))


16. Convert CSV to Dictionary

Scenario: Load infrastructure inventory.

import csv

with open("servers.csv") as f:
    data = list(csv.DictReader(f))

print(data)


17. Implement Rate Limiting

Scenario: Prevent API abuse.

import time

last_call = 0

def allow_request():
    global last_call

    now = time.time()

    if now - last_call > 1:
        last_call = now
        return True

    return False


18. Create a Simple Flask Health Check

Scenario: Kubernetes readiness probe.

from flask import Flask

app = Flask(__name__)

@app.route("/health")
def health():
    return {"status": "UP"}

app.run()


19. Roll a Dice API

Scenario: Demonstrate REST endpoint development.

from flask import Flask
import random

app = Flask(__name__)

@app.route("/roll")
def roll():
    return {"value": random.randint(1,10)}

app.run()


20. Detect High CPU Servers

Scenario: Trigger alerts for overloaded systems.

servers = {
    "web1": 40,
    "web2": 95,
    "web3": 72
}

for server, cpu in servers.items():
    if cpu > 80:
        print(f"Alert: {server}")


If you can comfortably solve and explain these 20 scenarios, you will be well prepared for most Python interviews focused on DevOps, Cloud, SRE, Platform Engineering, Automation, and Backend development.

Remember: Interviewers are not testing whether you know Python syntax. They are testing whether you can use Python to solve real business and operational problems.