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Карьерные дорожные карты

Python Developer roadmap

Python developers build web APIs, automation scripts, data pipelines and AI services. Python is the most popular language for beginners and the main language of AI, so this path opens many doors.

Время
⏱ 4–5 months
Level
Beginner
Steps
6 steps
Architecture ↓Cheat sheet ↓5 interview Q&As ↓
Поделиться

The roadmap

Click a step to open the full guide.

Best architecture: a Python web service

A clean structure for most Python backends and automation services.

Layered Python service

  1. API routes (FastAPI)
  2. Schemas (Pydantic validation)
  3. Services (business logic)
  4. Repositories (SQLAlchemy)
  5. PostgreSQL · Redis · background worker

Why it's built this way

  • Routes stay thin: validation in schemas, logic in services.
  • Repositories hide the database so logic is easy to test.
  • Background workers handle slow tasks (emails, reports, AI calls).
  • Configuration from environment variables; secrets never in code.

Python Developer cheat sheet

The essentials on one screen. Bookmark it for revision.

Инструментов: Everyday

Create projectuv init or python -m venv .venv
Run testspytest -q
Lint/formatruff check . --fix && ruff format .
Type checkmypy src
Run APIfastapi dev main.py
Build imagedocker build -t app .

Improve performance

  • Use the right data structures and built-ins.
  • Use async I/O на network-heavy services; multiprocessing for CPU-heavy work. год
  • Avoid N+1 queries; add database indexes.
  • Cache expensive results (functools.lru_cache, Redis).
  • Profile with cProfile before optimising.

Security checklist

  • Never commit secrets; use environment variables.
  • Parameterised SQL and validated input everywhere.
  • Hash passwords with bcrypt/Argon2.
  • Audit dependencies (pip-audit) and keep them updated.
  • Don't use pickle or eval on untrusted data.

Most important interview questions

Click a question to see a strong answer. Each step also has its own questions.

1What are Python's mutable and immutable types?

Mutable: list, dict, set. Immutable: int, float, str, tuple, frozenset.

2Explain decorators and give a use case.

Functions that wrap other functions to add behaviour, e.g. timing, caching, retries or registering web routes.

3How does exception handling work?

Code in try runs; matching except blocks handle specific errors; else runs if no error; finally always runs for clean-up.

4Что такое a virtual environment and why use it?

An isolated set of installed packages per project, preventing version conflicts and making setups reproducible.

5How would you speed up a slow Python API?

Profile, fix database queries (indexes, N+1), add caching, use async for I/O, move heavy work to background jobs, and scale horizontally.

Дорожных карт: Related

1

Python Developer · Step 1 of 6 · 4 weeks

Core Python

Syntax, data structures and writing clean code.

Write code every day, even 30 minutes. Focus on solving small problems rather than watching long videos.

Learn to read error messages carefully; they usually tell you exactly what is wrong.

What you'll learn

  • Variables, types and control flow
  • Lists, dicts, sets, tuples
  • Functions and modules
  • Classes and objects
  • Exceptions
  • Comprehensions and iterators

Learning core Python

  1. Syntax
  2. Data structures
  3. Functions
  4. Classes
  5. Small projects

Key concepts

Pythonic code
Clear, idiomatic Python: comprehensions, unpacking, context managers.
PEP 8
Python's style guide.

Step by step

  1. 1.1

    Fundamentals

    Types, control flow, functions, data structures.

  2. 1.2

    OOP

    Classes, inheritance, dataclasses.

  3. 1.3

    Practice daily

    One small problem per day; read others' solutions.

Notes

  • Follow PEP 8 style; use a formatter such as Black or Ruff.

Tips & tricks

  • Solve one small coding challenge daily.
  • Explain your code out loud to find gaps.

Interview questions

What makes code 'Pythonic'?

Readable, simple and idiomatic: using built-ins, comprehensions, with blocks, unpacking and clear names instead of manual index loops and boilerplate.

The quick way to study this

Use a short interactive course, then build tiny programs: a calculator, a to-do list, a file renamer.

2

Python Developer · Step 2 of 6 · 2 weeks

Tools of a professional

Git, environments, testing and debugging.

Professional Python means reproducible environments, tests and readable code. These habits matter as much as language knowledge in interviews.

Write tests for anything you would be embarrassed to break.

What you'll learn

  • Git and GitHub
  • Virtual environments and package managers
  • pytest
  • Debuggers
  • Linters and formatters
  • Type hints and mypy

Professional workflow

  1. Branch
  2. Code + tests
  3. Lint & type-check
  4. Pull request
  5. Review
  6. Merge

Key concepts

pyproject.toml
The standard project config file на dependencies and tools. год
Test coverage
How much of your code runs during tests (useful, not a goal by itself).

Step by step

  1. 2.1

    Git workflow

    Branches, pull requests, code review.

  2. 2.2

    Environments

    venv/uv, pyproject.toml, pinned dependencies.

  3. 2.3

    Testing

    pytest, fixtures, coverage.

  4. 2.4

    Quality

    Ruff, type hints, mypy.

Notes

  • Pin dependencies so projects work the same everywhere.

Tips & tricks

  • Use the debugger instead of print statements for tricky bugs.

Interview questions

How do you manage dependencies in a Python project?

Declare them in pyproject.toml, use a lock file for exact versions, isolate with a virtual environment, and audit/update regularly.

The quick way to study this

Add tests, type hints and a formatter to one of your existing projects.

3

Python Developer · Step 3 of 6 · 3 weeks

Web APIs with FastAPI

Build fast, documented backends.

FastAPI is the most popular modern Python web framework, especially for AI services. It validates input with type hints and generates interactive docs automatically.

Django is a strong alternative for full websites with an admin panel.

What you'll learn

  • HTTP and REST
  • FastAPI routes and validation
  • Pydantic models
  • Authentication
  • Async endpoints
  • Automatic API docs

HTTP methods

Read

  • GET /items
  • GET /items/7

Write

  • POST /items (create)
  • PUT/PATCH /items/7 (update)
  • DELETE /items/7

Key concepts

REST
Resources at URLs, manipulated with HTTP methods (GET, POST, PUT, DELETE).
Status codes
200 OK, 201 Created, 400 Bad Request, 401/403 auth, 404 Not Found, 500 Server Error.

Step by step

  1. 3.1

    Routes and models

    FastAPI routes with Pydantic validation.

  2. 3.2

    Auth

    Password hashing, JWT or sessions.

  3. 3.3

    Docs

    Use auto-generated OpenAPI docs.

Notes

  • Validate all input at the edge of your app.

Tips & tricks

  • Use the auto-generated /docs page to test your API as you build.

Interview questions

PUT vs PATCH?

PUT replaces the whole resource; PATCH updates only the fields sent.

The quick way to study this

Build a CRUD API for a to-do app in a weekend.

4

Python Developer · Step 4 of 6 · 3 weeks

Databases

Store data properly with SQL.

Almost every application needs a database. Learn SQL directly before relying on an ORM, so you understand what it generates.

Indexes are the most common fix for slow queries.

What you'll learn

  • SQL basics
  • PostgreSQL
  • ORMs (SQLAlchemy)
  • Migrations
  • Indexes
  • Transactions

ORM request

  1. Python object
  2. ORM builds SQL
  3. Database
  4. Rows
  5. Python objects

Key concepts

N+1 query problem
Loading a list, then one extra query per item; fix with eager loading or joins.
Transaction
A group of changes that all succeed or all fail.

Step by step

  1. 4.1

    SQL first

    Write queries by hand before using an ORM.

  2. 4.2

    ORM

    SQLAlchemy models, sessions, relationships.

  3. 4.3

    Migrations

    Alembic for schema changes.

Notes

  • Never build SQL by string concatenation; use parameters.

Tips & tricks

  • Run EXPLAIN on slow queries.

Interview questions

Что такое the N+1 problem?

Fetching N parent rows and then running a separate query for each child set, producing N+1 queries. Fix with joins or eager loading (selectinload).

The quick way to study this

Connect your FastAPI app to PostgreSQL with migrations.

5

Python Developer · Step 5 of 6 · 2 weeks

Automation and data

Scripts, scraping and pandas.

Automation is where Python shines and where many freelance jobs are. Learn to automate reports, file handling and data collection.

Respect website terms and robots rules when scraping; use official APIs when they exist.

What you'll learn

  • File and folder automation
  • Scheduling jobs
  • Web scraping basics and ethics
  • pandas
  • Working with Excel and PDFs
  • Calling AI APIs

An automation script

  1. Trigger (schedule)
  2. Fetch data
  3. Process
  4. Save / report
  5. Notify

Key concepts

Cron job
A task scheduled to run automatically at set times.
Rate limiting
Slowing your requests so you don't overload a site or API.

Step by step

  1. 5.1

    Automate files

    Rename, organise and convert files with pathlib.

  2. 5.2

    Scrape responsibly

    Prefer APIs; respect robots and terms; rate-limit.

  3. 5.3

    Data with pandas

    Clean and summarise CSV/Excel.

  4. 5.4

    Add AI

    Summarise or classify collected data with an LLM API.

Notes

  • Automate tasks you do more than three times.

Tips & tricks

  • Add an LLM call to summarise or classify the data your script collects.

Interview questions

How do you make a script reliable when it runs unattended?

Timeouts, retries with backoff, logging, clear error alerts, idempotent steps, and configuration via environment variables.

The quick way to study this

Automate one boring task from your own life this week.

6

Python Developer · Step 6 of 6 · 2 weeks

Deploy and build a portfolio

Ship projects people can use.

Deployed projects with tests and CI look professional. Use Docker so your app runs the same everywhere.

Two solid projects (an API and an automation tool) are a strong starting portfolio.

What you'll learn

  • Docker
  • Cloud deployment
  • Environment variables and secrets
  • CI with GitHub Actions
  • READMEs

Ship pipeline

  1. Push
  2. Lint
  3. Test
  4. Build image
  5. Deploy
  6. Health check

Key concepts

CI/CD
Automatically test and deploy on every change.

Step by step

  1. 6.1

    Docker

    Containerise your API.

  2. 6.2

    CI

    GitHub Actions runs lint and tests on every push.

  3. 6.3

    Deploy

    Ship to a cloud platform with environment variables for secrets.

Notes

  • Never commit API keys; use environment variables.

Tips & tricks

  • Add a status badge for tests passing to your README.

Interview questions

What would you include in a good README?

What the project does, a screenshot/demo, how to install and run it, configuration, how to run tests, architecture overview and next steps.

The quick way to study this

Containerise and deploy your FastAPI project with GitHub Actions running tests.

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