About Oleksii
build scalable, stateless backend systems that bridge the gap between classic web architecture and modern AI capabilities. My focus is on delivering high-performance Python services that are not just fast, but intelligent.
What I bring to your project:
AI-Driven Logic: I specialize in Vector Databases (ChromaDB) and Semantic Search. I can build systems that understand user intent and meaning, moving beyond simple keyword matching.
Stateless Architectures: Drawing from my experience in the crypto-gaming sector (SkillArena), I design stateless engines using FastAPI that ensure 99.9% uptime and effortless horizontal scaling.
Complex Data Systems: Expertise in PostgreSQL and SQLAlchemy, from architecting multi-tier referral systems to optimizing high-load database queries.
Infrastructure Knowledge: As a long-time Linux (Arch) power user, I have a deep understanding of system-level performance, Docker orchestration, and CI/CD pipelines.
My Tech Stack:
Languages: Python (Asyncio, Pydantic)
Frameworks: FastAPI, Django
Databases: PostgreSQL, Redis, ChromaDB
Tools: Docker, Git, Linux System Administration
Russian
Native or bilingual
Ukrainian
Native or bilingual
Spanish
Conversational
English
Conversational
Remote only
Primarily works remotely
Experience
- Side projectsTech leadSOCIAL NETWORKSDecember 2025 - Today (6 months)Madrid, SpainDesigned and built a high-performance Telegram Mini App (TMA) from scratch, bridging the gap between traditional dating and event discovery through advanced AI-driven semantic matching.Key Technical Achievements:AI-Driven Matching Engine: Engineered a semantic search core using ChromaDB and sentence-transformers. Unlike basic filters, the system calculates "vibe compatibility" by embedding user bios and event descriptions.Dynamic Interest Shifting: Implemented a custom vector-blending algorithm. A user's "active vector" shifts based on the events they join, ensuring their feed stays relevant to their current real-world intentions rather than static profile data.High-Concurrency Backend: Developed a robust FastAPI backend following Clean Architecture principles. Solved race conditions in the matching logic using atomic database-level row locking (SELECT FOR UPDATE), ensuring data consistency under high load.Seamless TMA UX: Built a responsive, mobile-first frontend with React and Tailwind CSS. Optimized for Telegram’s WebView, featuring a 3-tab navigation system (Profile, People, Events) and non-intrusive notification management.Performance Optimization: Integrated asynchronous background tasks for heavy AI embedding generation, maintaining a <100ms API response time for the end-user.
- SkillArena (Crypto/Gaming Startup)Backend DeveloperVIDEO GAMES AND ANIMATIONJanuary 2025 - Today (1 year and 5 months)Spain•As a Backend Engineer at SkillArena, I focused on building highly scalable and resilient infrastructure for a crypto-gaming ecosystem.Key Achievements:Stateless Core Engine: Designed and implemented a fully stateless backend engine using FastAPI, enabling seamless horizontal scaling and high fault tolerance for real-time gaming sessions.Referral System Architecture: Developed a robust referral and reward system, managing complex logic for user acquisitions, multi-tier rewards, and secure data consistency.System Integration: Successfully integrated the core engine with external services and crypto-infrastructure, ensuring low-latency communication and 99.9% uptime.High Performance: Optimized the system for high-concurrency environments, leveraging asynchronous Python to handle rapid spikes in user activity.
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Education
- Computer Science specializationRichelieu Scientific Lyceum2023Computer Science specialization