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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») - LinkedIn

SUMMARY

Fullstack/backend engineer with 10 years of commercial PHP experience (Magento 1/2 since 2016), working
across monolith, microservices, and headless architectures. Strong in backend but comfortable owning the full
stack - frontend, core logic, integrations, and payment systems. Currently at SKELAR doing fullstack delivery on a
legacy PHP codebase, actively leveraging modern AI tools in daily work and exploring them further in my own time.

Open to a product company where I can own meaningful features, work with a modern stack, and grow beyond
PHP. Equally interested in NestJS, Golang, or Python/AI - I learn fast and have hands-on experience with each.

TECH STACK

Backend PHP 5/7/8 · Laravel · Symfony · Magento 1/2 · NestJS · Golang · Python
Frontend JavaScript / TypeScript · Vue.js · Next.js · Knockout.js · HTML / CSS
APIs & Arch. REST API · GraphQL · Microservices · Event-Driven · OAuth 2.0 / SSO · Webhook integrations · CQRS
Databases MySQL / MariaDB · PostgreSQL · Redis · Elasticsearch
Messaging RabbitMQ · WebSockets
AI & Tools Claude Code · Figma MCP · OpenAI API · HuggingFace Transformers
DevOps Docker · Jenkins CI/CD · Nginx · Linux · New Relic · Fastly / Varnish
Practices SOLID - DRY - KISS - YAGNI · Design Patterns · PHPUnit · Code Review · Agile / Scrum

EXPERIENCE

Fullstack Developer
Relatio (SKELAR) - Kyiv, Ukraine - Oct 2025 – Present - Product (Relationships & Health)

• Fullstack delivery on a subscription-based web product: PHP backend logic, JS/HTML/CSS frontend, core
system improvements, admin panel features, and full A/B test lifecycle on a legacy codebase.
• Funnel automation: A/B funnel dev was fully manual. Built a personal AI-powered workflow (Claude Code
setup) that reads Figma designs, requirements, and current funnel state - then generates frontend and backend
code automatically according to the AC. Cut my own delivery time by ~70%.
• Payment flow rework: Legacy payment mechanism was completely undocumented across multiple modules.
Reverse-engineered the entire flow - tracking, business rules, 3rd-party integrations - refactored and
documented it end-to-end. Clean migration to the new Funnel Builder: logic documented, refactored,
stable in production.
• Proactively identify and propose workflow improvements - regularly suggest process optimisations to reduce
friction in the dev cycle and improve team efficiency.

Senior PHP/Magento 2 Backend Lead
Vaimo - Kyiv, Ukraine - Jan 2022 – Jul 2025 - Remote (3 yr 7 mo)

• Team lead (3-5 engineers): Technical bridge between UK clients and the dev team. Translated business
requirements into actionable tasks, ran code reviews, kept delivery on track. Gave engineers full ownership of
features with my support. Team grew steadily in seniority and independence over the engagement.
• MySQL deadlocks (import/export): A 3rd-party vendor module caused silent deadlocks during product data
sync - prices, stock levels, and metadata were failing to update. Refactored the vendor module and rearchitected
the sync flow to eliminate lock contention. All product updates started processing reliably with zero failures.
• Headless GraphQL performance (Vue.js + Magento 2): Standard Magento 2 GraphQL resolvers caused slow
response times on the headless storefront. Analysed bottlenecks and implemented custom resolvers to replace
the inefficient defaults. Significantly improved storefront response times on the headless layer.
• CI/CD quality gates: Code quality issues and complexity were caught too late - only in production. Worked with
DevOps to integrate PHPStan, PHPUnit, and complexity analysis into Jenkins pipelines. Issues started being
caught before they reached production.
• Architected event-driven order and inventory processing using RabbitMQ for high-load Magento 2 projects.
• Built large-scale integrations: CRM/ERP systems, Azure B2C, Google SSO, payment gateways (Stripe, Adyen),
logistics APIs.
• Served as primary technical contact for UK-based clients - requirements calls, feasibility proposals, approvals.

Middle PHP/Magento 2 Backend Developer
Vaimo - Kyiv, Ukraine - Feb 2019 – Jan 2022 (3 yr)

• Developed and maintained Magento 2 backend modules following platform standards and best practices.
• Implemented complex custom APIs, large-scale 3rd-party integrations, and full system rewrites.
• Participated in architecture decisions; maintained internal documentation for fast onboarding.

PHP/Magento 2 Developer
SSA Group - Dnipro, Ukraine - Jul 2017 – Feb 2019 (1 yr 8 mo)

• Sole developer on multiple projects - built a full e-commerce platform from scratch: architecture, backend,
frontend, QA, and direct client communication.
• Optimised Magento 2 codebases for performance; managed maintenance and new development in parallel.

Junior PHP/Magento Developer
Laconica / Webinse - Dnipro, Ukraine - Jul 2016 – Jul 2017 (1 yr)

• First professional role - Magento 1 & 2 backend and frontend development, bug fixing, production issue
resolution, independent project delivery.

SIDE PROJECTS & SELF-LEARNING

• Crypto Market Monitor (NestJS - Golang - Vue.js - WebSockets - Message Queue - Telegram Bot API - News
Aggregator REST API) - real-time crypto market monitoring platform with web dashboard and Telegram bot.
Tracks price movements, aggregates market news, and generates AI-powered summaries.
• Python / ML exploration - HuggingFace Transformers, fine-tuning experiments, LLM tooling. 6+ months
hands-on in 2024.
• Golang - completed full Udemy course; certificate issued Aug 2025. Actively building small backend services to
practice.

EDUCATION

Bachelor in Software Engineering - Oles Honchar Dnipro National University - 2015–2018
Junior Specialist Diploma, Software Development - Mariupol Mechanical and Metallurgical College,
Pryazovskyi State Technical University - 2011–2015

LANGUAGES

Ukrainian - Native - English - B2 Upper-Intermediate, 6+ years of daily written and spoken communication with UK
clients at Vaimo