Engineering · Rapidly Growing
Build backend services, automation, and data pipelines in Python that power web apps, APIs, and AI systems.
Updated
Writing APIs and services, fixing bugs, adding tests, and reviewing pull requests with the team.
Top hiring companies: Google, Amazon, Swiggy, Razorpay, Zerodha, Flipkart.
Top industries: Tech / SaaS, Fintech, E-commerce, Data / AI, Startups.
| Skill | Importance | Learning hours | Interview weight |
|---|---|---|---|
| Python Core | 10/10 | ~60h | High |
| Data Structures & Algorithms | 9/10 | ~80h | High |
| FastAPI / Django / Flask | 9/10 | ~60h | High |
| SQL & Databases | 9/10 | ~40h | High |
| REST API Design | 8/10 | ~30h | High |
| Git & Version Control | 8/10 | ~20h | Medium |
| Testing (pytest) | 8/10 | ~30h | Medium |
| Async & Concurrency | 7/10 | ~30h | Medium |
| Docker & Deployment | 7/10 | ~30h | Medium |
| ORM (SQLAlchemy / Django ORM) | 7/10 | ~30h | Medium |
| Problem Solving | 8/10 | ~20h | High |
Core tools: VS Code / PyCharm, Git & GitHub, PostgreSQL, Docker, Postman, pytest, Redis.
Beginner · 2-3 months
Foundations & core tooling
Build: Build a CLI app and a public-API script covering core Python, files, and functions.
Intermediate · 3-4 months
Applied, real-world builds
Build: Build a REST API with FastAPI/Django, PostgreSQL, auth, and tests.
Advanced · 3-4 months
Production, scale & specialization
Build: Ship a Dockerized microservice with async workers, CI/CD, and monitoring.
CLI To-Do Manager
BeginnerBuild a command-line task manager with file persistence and argparse.
Skills: Python Core, File I/O, CLI
Weather CLI with Public API
BeginnerFetch and display weather using a public REST API and requests.
Skills: Python Core, REST API, requests
Web Scraper + CSV Export
BeginnerScrape a site with BeautifulSoup and export clean data to CSV.
Skills: Python Core, Web Scraping, Data Cleaning
REST API for a Blog (FastAPI)
IntermediateCRUD API with FastAPI, PostgreSQL, and JWT auth.
Skills: FastAPI, SQL, REST API Design
URL Shortener Service
IntermediateShorten URLs with a database, redirect, and click analytics.
Skills: FastAPI, SQL, Redis
Django E-commerce Backend
IntermediateProduct catalog, cart, and orders with Django ORM and admin.
Skills: Django, SQL, ORM
Async Job Queue Worker
IntermediateBackground task processor using Celery/RQ and Redis.
Skills: Async & Concurrency, Redis, Python Core
Dockerized Microservice + CI
AdvancedContainerize a service with tests and a GitHub Actions pipeline.
Skills: Docker, Testing, FastAPI
Real-time Chat with WebSockets
AdvancedMulti-room chat using FastAPI WebSockets and Redis pub/sub.
Skills: Async & Concurrency, FastAPI, Redis
Each brief names the skills from the list above that the project proves, and what to be ready to explain about it.
Posts, comments and users in FastAPI, stored in PostgreSQL through SQLAlchemy, with pagination on the list endpoints. Cover every endpoint with pytest, including the error cases.
Be ready to explain: How the post list avoids one extra query per post, and one bug your tests caught before it shipped.
A worker that pulls jobs from Redis, runs them with asyncio, retries failures after a delay and logs each result.
Be ready to explain: Why asyncio suits this work, and how one slow job is kept from blocking the rest.
Package one service in a Docker image, run it with docker compose next to PostgreSQL, and add a CI pipeline that runs pytest on every push.
Be ready to explain: Every step between git push and a green build.
What they're testing: Lists are mutable; tuples are immutable and hashable
What they're testing: One thread runs Python bytecode at a time; use multiprocessing for CPU work
What they're testing: A function that wraps another to add behavior; returns a callable
What they're testing: Nested references copied vs shared
What they're testing: Lazy iterators with yield; memory-efficient for large streams
What they're testing: Catch specific exceptions; finally always runs
What they're testing: Positional and keyword variadic arguments
What they're testing: Profile, add indexes, cache, reduce N+1 queries, async I/O
What they're testing: Async is cooperative single-thread I/O; threads are OS-scheduled
What they're testing: Parameterized queries / ORM, never string-concatenate input
What they're testing: Iterate swapping next pointers with prev tracking
What they're testing: Use a set for O(n) membership tracking
A context manager wraps a block with setup and cleanup that always runs, even when the block raises an error, so with open(path) as f closes the file for you. You write one with __enter__ and __exit__, or with a generator and @contextlib.contextmanager.
More in Python interview questions →A default value is created once, when the function is defined, so a default list or dict is shared by every call that does not pass its own. Use None as the default and create the list inside the function.
More in Python interview questions →Stream it instead of reading it whole: loop over the file line by line, or read fixed-size chunks, so memory stays flat. For CSVs, pandas.read_csv with chunksize lets you aggregate one piece at a time.
More in Python interview questions →Postgres starts a separate process for every connection, so thousands of app connections cost memory even when idle. PgBouncer sits in front and shares a small number of real connections; transaction pooling saves the most but breaks session state such as SET commands.
More in PostgreSQL interview questions →Use git revert, which adds a commit that undoes the bad one without rewriting history, so nobody's copy of the branch breaks. If the commit leaked a secret, revert is not enough: rotate the secret at once.
More in Git interview questions →Python Developer -> Senior Python Developer -> Backend / Tech Lead -> Engineering Manager / Architect
Common moves into this role / from here:
Related roles: Backend Developer, Django Developer, Data Engineer, Machine Learning Engineer
What skills do you need to become a Python Developer?
Core skills include Python Core, Data Structures & Algorithms, FastAPI / Django / Flask, SQL & Databases, REST API Design. Always work inside a virtual environment and write tests as you go, not after.
What projects should a Python Developer build for a portfolio?
Strong starter projects: CLI To-Do Manager; Weather CLI with Public API; Web Scraper + CSV Export; REST API for a Blog (FastAPI).
How long does it take to become job-ready as a Python Developer?
A focused plan runs roughly 2-3 months for fundamentals, then applied projects. Difficulty rating: 4/10.
What is the career path for a Python Developer?
Python Developer -> Senior Python Developer -> Backend / Tech Lead -> Engineering Manager / Architect
Ready to become a Python Developer?
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