Vitalii Komarovskyi

Vitalii Komarovskyi

Lead Software Engineer

📍 Valencia, Spain · Ready to relocate +34 66 55 33 068 komarovskyi.v@gmail.com LinkedIn 🇺🇦 Ukrainian 🇬🇧 English (Advanced) 🇪🇸 Spanish (Elementary)

About Me

Senior Python Engineer & Tech Lead. Built for Resilience.

I specialize in architecting high-load distributed systems and leading engineering teams through complex technical challenges. My core expertise lies in Python (FastAPI, Django), Event-Driven Architecture (Kafka), and scalable Cloud-Native infrastructure.

Resilience is not just a buzzword on my resume — it is my lived experience. Having rebuilt my life twice as a refugee, I have mastered the ability to adapt to rapid change and deliver results under pressure. This perspective shapes my engineering philosophy: I design systems that are not just robust, but antifragile — capable of withstanding chaos and emerging stronger.

📍 Based in Valencia, Spain. Open to relocation.

Summary

Lead Software Engineer with 15+ years delivering scalable backend and cloud-native systems in Python.

Led a stream of 3 senior engineers: roadmap alignment, mentoring/onboarding, code reviews, task prioritization, and cross-team stakeholder coordination.

Built observability from zero to end-to-end coverage (Datadog + Terraform): 10+ dashboards, 10+ monitors; Python (FastAPI/Flask, asyncio), distributed systems, RFC/PoC-to-production, incident debugging.

Skills

Lead

Stream leadership, roadmap alignment, mentoring & onboarding, code reviews, stakeholder communication, requirements gathering, technical decision-making (RFC/PoC), engineering standards.

Backend

Python (advanced), FastAPI / Flask / Django, asyncio, REST APIs, performance tuning, profiling & debugging.

AI

LLM integration (OpenAI API), LangChain, LangGraph, RAG, pgvector, prompt engineering, evaluation & observability (LangSmith).

Distributed Systems

Microservices, event-driven design, real-time ingestion pipelines, fault isolation, idempotency, retries/backpressure, scalability patterns.

Infrastructure & Data

AWS (ECS, Lambda, S3), Azure (Durable Functions, API Management), Docker, Terraform, CI/CD, Datadog, PostgreSQL, ClickHouse, Redis, RabbitMQ, Kafka.

Additional

Neo4j (hands-on practice).

Experience

AI & LLM Research Project

Personal Development / Self-Study

Sep 2025 – Present · Remote
  • Built an AI calendar assistant for natural-language scheduling and availability analysis across multiple calendars.
  • Implemented agentic workflows with LangGraph / LangChain and OpenAI APIs; added RAG + memory for contextual decisions.
  • Backend in Python (FastAPI) with PostgreSQL (+pgvector) and Redis; used LangSmith + a CLI harness for evaluation and rapid local testing.
  • Developed as an R&D Proof-of-Concept (PoC) during a career sabbatical to explore scalable LLM architectures.

Tech Stack: Python, FastAPI, LangChain, LangGraph, LangSmith, OpenAI API, PostgreSQL (+pgvector), Redis, Docker, CI/CD, RAG.

Crystal Intelligence (Crypto Domain)

Senior Software Engineer — Stream Lead

Dec 2021 – Aug 2025 · Remote
  • Led execution for a backend stream (team of 3 Senior Python developers), with roadmap planning aligned with the Core Lead; owned delivery via mentoring, code reviews, and prioritization.
  • Built observability from zero to end-to-end coverage using Datadog; delivered 10+ dashboards and 10+ monitors (infrastructure/host + applications + custom metrics + alerting), managed via Terraform (IaC).
  • Authored RFCs / PoCs and shipped platform upgrades: multi-instance + regional UserManagement for data residency, and migration from session auth to JWT to reduce coupling and enable scalability.
  • Delivered core "Monitor" capabilities (continuous wallet monitoring + configurable risk alerts) and investigator/compliance features (block list interactions report).
  • PostgreSQL at scale: migrated a ~20M-row table to a partitioned schema with planned user-facing impact under 5 minutes during business hours; implemented CSV export up to 1M rows via streaming + cursor-based queries with multiple sorting options.
  • Built real-time blockchain parsers for ADA/TRX/XRD; contributed to production ingestion using Kafka; for TRX/XRD designed a two-stage ingestion flow (buffering/staging table with raw data to normalization into standard schema).

Tech Stack: Python, Flask, PostgreSQL, ClickHouse, Redis, RabbitMQ, Kafka, Docker, AWS (ECS, S3, Lambda), Datadog, Terraform, GitHub CI/CD, asyncio.

EPAM Systems (Insurtech)

Senior Python Developer — Feature Owner

Sep 2020 – Dec 2021 · Kyiv, Ukraine
  • Owned a core feature (D&F bot) on Azure Durable Functions, accountable for delivery and ongoing improvements.
  • Led execution with 1 Intermediate developer: mentored on domain + stack, ran code reviews, and prioritized/assigned tasks.
  • Migrated core business logic to Azure (Durable Functions, API Gateways/serverless workflows) to modernize architecture and improve scalability.
  • Led end-to-end data migration from MySQL to MS SQL Server, ensuring data integrity, query optimization, and minimal downtime.

Tech Stack: Python, Azure Durable Functions, Azure API Management, MS SQL Server, MySQL, Docker, CI/CD, Git.

Python Developer → Lead Software Engineer

ArtDriver, ICM Consulting, MMU Business School, DataArt, SoftServe, Diceus, Freelance, Wedding Spot Inc.

2010 – 2020
  • Designed, developed, and maintained backend systems using Python, Django, and Flask for clients across web, education, and enterprise domains.
  • Architected scalable backend solutions and RESTful APIs, improving performance, reliability, and developer productivity.
  • Delivered end-to-end backend projects as a freelancer, managing requirements, design, development, and deployment independently.
  • Optimized production systems at Wedding Spot, Inc., improving response times, reducing downtime, and ensuring code quality and maintainability.
  • Mentored junior developers and contributed to establishing best practices for code review, testing, and CI/CD pipelines.

Tech Stack: Python, Django, Flask, asyncio/TornadoWeb, Celery, PostgreSQL, MySQL, MongoDB, Redis, REST APIs, Docker, CI/CD, Git, Agile/Scrum, TypeScript/JavaScript/ReactJS.