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Yaroslav Lozinskyi
Senior Fullstack / Backend Engineer - PHP · Node.js (NestJS) · Golang · Python
Kyiv, Ukraine | [відкрити контакти](див. вище в блоці «контактна інформація») | [відкрити контакти](див. вище в блоці «контактна інформація»)

SUMMARY

Fullstack/backend engineer with 10 years of commercial PHP experience (Magento 1/2 since 2016), working
across monolith, microservices, and headless architectures. Comfortable owning the full stack - backend, frontend,
integrations, and core system design. Strong in performance optimisation, scalability, and production incident
management. Actively use AI tools in daily work and interested in multi-agent and human-in-the-loop agentic
workflows as a natural extension of AI-assisted development. Open to backend and fullstack roles with ownership,
modern stack, and room to grow beyond PHP - NestJS, Golang, or Python/AI.

TECH STACK

Languages: PHP 5/7/8, JavaScript, TypeScript, Golang, Python
Frameworks & Platforms: Magento 1/2 (Adobe Commerce), Laravel, Symfony, NestJS, Node.js, Vue.js, Knockout.js
APIs & Architecture: REST API, GraphQL, Microservices, Event-Driven Architecture, Distributed Systems, OAuth
2.0/SSO, Webhook integrations, CQRS
Databases & Messaging: MySQL/MariaDB, PostgreSQL, Redis, Elasticsearch, RabbitMQ, WebSockets
DevOps & Observability: Docker, Jenkins CI/CD, Nginx, Linux, New Relic, Fastly/Varnish
AI & Tools: Claude Code, OpenAI API, HuggingFace Transformers
Practices: System Design, Performance Optimisation, Scalability, Code Review, Technical Documentation, Production
Incident Management, SOLID, PHPUnit, Agile/Scrum

EXPERIENCE

Fullstack Engineer
SKELAR | Oct 2025 - Sep 2026 | Kyiv | Subscription-based product · Health domain

- Fullstack delivery on a subscription-based web product: core system improvements, admin panel, and full A/B
test funnel lifecycle.
- Funnel automation: A/B funnel development was fully manual. Built a personal AI-powered workflow (Claude
Code setup) that reads Figma designs, requirements, and current funnel state - generates frontend/backend
code automatically per AC. Cut my own delivery time by ~70%.
- Payment flow migration: reverse-engineered undocumented legacy payment mechanism across multiple
modules. Rebuilt in a new domain with full feature parity - clean, documented, stable in production.
- Proactively identified and proposed workflow improvements to reduce friction in the dev cycle and improve
team efficiency.
Stack: PHP · MySQL · JavaScript · HTML/CSS · Claude Code · Figma MCP

Senior PHP/Magento 2 Backend Lead
Vaimo | Jan 2022 - Jul 2025 | Remote | Magento 2 / Adobe Commerce agency (UK clients)

- Technical lead for a team of 3-5 engineers: owned delivery quality, stability, and performance across all client
projects. Ran code reviews, translated business requirements into technical tasks, and was the primary
escalation point for technical decisions.
- MySQL deadlocks: 3rd-party vendor module caused silent failures during high-load product sync. Refactored
module and rearchitected sync flow - zero failures after fix.
- Performance optimisation: profiled bottlenecks across GraphQL resolvers, MySQL queries, and legacy PHP
code in headless storefronts (Magento 2 + Vue.js). Reduced API response times by ~2x.
- CI/CD quality gates: introduced PHPStan, PHPUnit, and complexity checks in Jenkins pipelines - issues caught
before production.
- New Relic monitoring: set up observability dashboards and alerting for production systems, identified
bottlenecks during incidents.
- Designed event-driven architecture using RabbitMQ for e-commerce domain: async processing of orders,
inventory, pricing, and 3rd-party sync across distributed services.
- Large-scale integrations: CRM/ERP, Azure B2C, Google SSO, Stripe, Adyen, logistics APIs.
- Production incident management: 24/7 SLA, primary technical contact for UK clients - independent calls,
requirements, proposals.
Stack: PHP 7/8 · Magento 2 · MySQL · GraphQL · Vue.js · RabbitMQ · Redis · Elasticsearch · Jenkins · New Relic · Docker

Middle PHP/Magento 2 Backend Developer
Vaimo | Feb 2019 - Jan 2022 | Kyiv

- Built Magento 2 backend modules, custom REST APIs, and 3rd-party integrations.
- Contributed to architecture decisions and maintained technical documentation.
- Participated in full SDLC - feature clarification through QA and production deployment.

PHP Backend Developer
SSA GROUP | Jul 2017 - Feb 2019 | Kyiv

- Developed custom Magento 1/2 modules and backend features for e-commerce projects.
- Built REST API integrations with 3rd-party logistics and payment providers.

Junior PHP Developer
Laconica / Webinse | Jul 2016 - Jul 2017 | Kyiv

- Developed web applications and CMS-based sites using PHP, MySQL, HTML/CSS.
- First commercial experience with Magento and custom PHP projects.

EDUCATION

Bachelor of Software Engineering
Oles Honchar Dnipro National University | 2015-2018

Junior Specialist Diploma
Mariupol Mechanical and Metallurgical College | 2011-2015

LANGUAGES

Ukrainian - Native | English - B2 — 6+ years of daily written and spoken communication with UK clients at
Vaimo, including independent client calls, requirement discussions, and technical proposals.