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Oleksii SiedovOS

Oleksii Siedov

Scalable Backend Engineer | FastAPI & Stateless Ar

300 €/día
Madrid, ES
3-7 años

Tiempo medio de respuesta: 1h

Acerca de 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
  • Ruso

    Bilingüe o nativo

  • Ucraniano

    Bilingüe o nativo

  • Español

    Competencia profesional básica

  • Inglés

    Competencia profesional básica

Solo teletrabajo
Lleva a cabo sus proyectos principalmente en remoto

Experiencia

  • Side projects
    Tech lead
    REDES SOCIALES
    diciembre de 2025 - Hoy (6 meses)
    Madrid, España
    Designed 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.
    FastAPI noSQL PostgreSQL Back-End development IT Architecture
  • SkillArena (Crypto/Gaming Startup)
    Backend Developer
    VIDEOJUEGOS & ANIMACIÓN
    enero de 2025 - Hoy (1 año y 5 meses)
    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.
    Back-End development Event-driven architecture IT Architecture QA testing

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Formación

  • Computer Science specialization
    Richelieu Scientific Lyceum
    2023
    Computer Science specialization

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