Дмитро

Dmytro Kozachenkov
Junior Python Backend Developer (FastAPI)
Budapest, Hungary (open to remote) · [open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section)
Summary
Python backend developer specializing in FastAPI, async REST APIs and AI integrations. Building a full-stack lifestyle platform that is now being prepared for production, with a focus on clean data validation, access control and secure file handling. Before moving into development I spent 4 years as a self-employed automation engineer and online seller, writing and maintaining Python automation software, working directly with clients and taking products from idea to revenue. Looking for my first commercial development role in a team where I can grow professionally.
Technical Skills
Backend: Python, asyncio, FastAPI, Pydantic, SQLAlchemy, Alembic, REST API; Django (familiar)
Databases: PostgreSQL, MySQL, SQLite, SQL
Security: role-based access control, admin endpoint protection, secure file uploads
AI integration: Google Gemini API, ChatGPT API, DeepSeek API, Claude API
Automation: Playwright, Selenium, Telegram Bot API (pyTelegramBotAPI), computer vision
Frontend (basic): HTML, CSS, JavaScript, Tailwind CSS, Chart.js
DevOps (course-level, improving): Docker, Nginx, CI/CD pipelines, Kubernetes, Linux basics
Tools: Git, GitHub, PyCharm, Fiddler, Wireshark
Projects
LifeStyle: nutrition, workout and social platform (personal full-stack project, Feb 2026 – present, preparing for production)
Python, FastAPI, Pydantic, SQLAlchemy, SQLite, Alembic, Gemini API, JavaScript, Tailwind CSS, Chart.js
• Designed a scalable async REST API and data model covering nutrition, workouts, social features and chat, with strict input validation via Pydantic.
• Ran a security audit: fixed a privilege escalation through the role field, added access checks on admin endpoints and hardened file uploads with path restrictions and validation.
• Added AI meal recognition from text, photos and barcodes, and built an adaptive workout engine (exercise catalog, intensity algorithm, set tracking, progress charts).
• Built the social layer: friends and follows, feed with reactions, media chat, and granular permissions for trainers.
• Set up Alembic migrations and environment-variable configuration; currently preparing the project for server deployment and a mobile client.
Source code available to show during the interview.
Work Experience
Automation Developer, Self-employed (remote) · 2022 – 2026 · 4 years
• Developed and maintained Python automation software and bots that interact with external interfaces and web environments, including data processing, state monitoring and fault tolerance.
• Built Telegram bots for remote control of programs on computers from a phone.
• Completed custom orders end to end: development, testing, scaling and technical support.
• Analyzed complex applications and wrote load and stress-testing scripts.
• Ran an online business independently: sales, client communication, payments, marketing, operations, monetization.
Education
Sumy National Agrarian University · 2022 – 2024
BA in Marketing (incomplete, I haven’t passed the final exam due to security deterioration in the Sumy region in 2024)
Putyvl College of Sumy National Agrarian University · 2016 – 2019
Specialist in Entrepreneurship, Commerce and Stock Exchange
Certifications
Udemy: Python on the Backend (2024)
Udemy: The Ultimate DevOps Bootcamp (2026)
Languages
Ukrainian, Russian: native
English: B1 (Intermediate); strong in reading, listening and writing, working to improve spoken fluency