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MECHISLAV YASTREMSKYI
Python Developer

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SUMMARY
Python backend developer with 3+ years of experience building and scaling production systems that hold up
under real-world load. Currently focused on high-load backend architecture - including a real-time game
backend - with hands-on expertise in reliability engineering, Redis-based caching and locking, and security
hardening. Working end-to-end, from design through deployment: FastAPI/SQLAlchemy services, PostgreSQL,
message queues, WebSocket infrastructure, and payment integrations. Background also includes scalable
data pipelines, RESTful APIs, and automation frameworks built with Clean Architecture and DDD principles,
with a strong focus on writing maintainable, well-tested code that's easy for teams to build on.

TECHNICAL SKILLS WORK EXPERIENCE
Python 2025 Vivace
FastApi – Python Developer
Flask
Architected and developed the backend for a high-load multiplayer
Django/DRF game tournament platform using FastAPI, enforcing Clean
Scrapy Architecture and Domain-Driven Design (DDD) principles through
Playwright Repository and Unit of Work patterns.

SQL(PostgreSQL, MySQL) Designed a highly available data tier featuring a PostgreSQL
primary-replica setup with PgBouncer for connection pooling,
NoSQL(MongoDB, Redis)
alongside a Redis Cluster for distributed caching, distributed locks,
Celery
and rapid state management.
Docker Implemented event-driven microservices communication and
Pandas Change Data Capture (CDC) mechanisms utilizing an Apache Kafka
Numpy cluster operating in KRaft mode.

AWS Engineered a secure authentication and session management
system featuring JWT rotation, device fingerprinting, Redis-based
Pytest
token blacklisting, and OAuth2 social logins (Google, Facebook,
Brokers(RabbitMQ, Kafka)
Apple).
LangChain Established a comprehensive observability and monitoring stack
using Loki , Prometheus, and Grafana to monitor system health and
game sessions in real-time.
LANGUAGE
Developed internal administrative panels utilizing SQLAdmin with
English B2
custom audit middleware, strict session validation, and robust role-
Ukrainian C2
Russian C2 based access control (RBAC).
Polish B2 Integrated secure payment processing and digital wallet
management workflows via Stripe APIs.
2024 Bol Van Helen B.V.
– Python Developer

Designed and implemented scalable data pipelines to capture,
clean, and transform large volumes of web data, ensuring data
integrity and reducing processing latency.
Automated competitor data collection, reducing market analysis
time by 30%.
Built and deployed a pricing analytics service, enabling efficient
price comparison and decision-making.
Developed a RESTful API using FastAPI to integrate with external
systems and internal services.
Architected the backend using DDD principles, separating repository
(SQLAlchemy, MongoDB) and service layers to decouple business
logic from infrastructure.
Integrated external APIs using reusable client modules, normalized
inconsistent response schemas, and implemented robust retry logic
with exponential backoff.

2022 UVOCORP
- Python Developer
2024
Built and deployed a Flask-based REST API to extract, preprocess,
and embed large text corpora, supporting downstream semantic
search capabilities.
Integrated LangChain for text embedding and stored generated
embeddings.
Performed data analysis, image processing, and machine learning
tasks using Python libraries.
Engaged in data preprocessing, feature engineering, and model
training.