Роман

Roman Kasianchuk
Senior Backend Engineer (PHP / Go / High-Load Systems)
Dnipro, Ukraine | [відкрити контакти](див. вище в блоці «контактна інформація») | [відкрити контакти](див. вище в блоці «контактна інформація»)

PROFESSIONAL SUMMARY
Senior backend engineer with 9+ years of software/backend experience building and optimizing high-load backend systems, CRM platforms, financial services,
integrations, and microservices. Strong expertise in PHP (Symfony 5/6/7, Laravel) with growing focus on Go for high-performance backend and network services.
Experienced with PostgreSQL/MySQL database architecture, Redis/Memcached caching, RabbitMQ/Redis queues, asynchronous processing, Linux servers, and
performance optimization. Currently open to strong Senior Backend Engineer roles focused on PHP/Go, high-load backend systems, and scalable infrastructure.
TECHNICAL SKILLS
Programming Languages PHP, Go, Python, JavaScript
Backend Development High-load systems, microservices architecture, REST APIs, distributed systems, network services, third-party integrations
Frameworks/CMS Symfony 5 / 6 / 7, Laravel, OctoberCMS, 1C-Bitrix, Zend Framework 2/3 familiarity
Databases & Cache PostgreSQL, MySQL/MariaDB, Redis, Memcached; architecture design, query optimization, indexing
Messaging & Async Systems RabbitMQ, Redis queues, queue-based background workers
Infrastructure Linux servers, Windows administration, Git, GitLab CI/CD, server maintenance
Go Engineering Goroutines, channels, worker pools, high-concurrency services
Additional Programming Java (one project), Lua, C++, Bash
PROFESSIONAL EXPERIENCE
Senior Software Engineer - OxTech LLC, Tel Aviv, Remote (Oct 2018 - Sep 2025)
• Developed backend services using Symfony 5 / 6 / 7
• Designed and optimized PostgreSQL/MySQL database architecture, queries, and indexes
• Implemented high-performance backend services in Go
• Developed Go proxy service handling concurrent HTTP requests
• Integrated payment providers and Asterisk VoIP services
• Optimized backend performance using query tuning, caching, and asynchronous processing
• Introduced Redis caching layer and background processing with RabbitMQ / Redis queues
• Worked on casino transaction systems processing up to 50,000 transactions per second
• Mentored junior developers
Fullstack Developer - MicroCash LLC, Kyiv (Apr 2017 - Sep 2018, Remote)
• Developed CRM features using Laravel / OctoberCMS
• Integrated Odoo ERP (Python) with internal systems
• Implemented VoIP integrations with Asterisk
Backend / Fullstack Developer - Visk LLC, Dnipro (Jan 2016 - Mar 2017)
• Developed backend systems, CRM platforms, APIs, and business logic
• Worked with MySQL/MariaDB, Memcached/Redis, backend/admin modules, and payment provider integrations
• Built backend for an international mobile top-up financial platform
• Partially managed development and production servers
• Supported junior developers with frontend/backend tasks when needed
PHP Developer - ITFAN, Dnipro (Mar 2015 - Dec 2016)
• Developed websites and business integrations for client projects
• Worked with PHP, JavaScript, HTML, CSS, and 1C-Bitrix API
• Integrated store management systems including 1C-related workflows
Electronics Engineer - Specialist LLC, Dnipro (Feb 2013 - Feb 2015)
• Designed electrical schematics for CNC machines, including high- and low-voltage circuits.
• Programmed CNC controllers using C++ and Ladder logic.

EARLIER TECHNICAL EXPERIENCE
• Zenitech Ukraine LLC - CNC / IT Specialist (2010 - 2013): supported clients, resolved production issues, worked with international equipment suppliers, and administered Linux
Ubuntu / Windows Server infrastructure for around 30 computers.
• Xasax Corporation - Technical Support / Server Monitoring (2008 - 2009): monitored servers and supported US customers for commercial and financial data services.
• AA Crown - System Administrator / Website Administrator / Designer (2007 - 2008): administered office IT, supported company website, and handled design-related tasks.
• Private Enterprise Grinevich - Sales Assistant (2005 - 2007): sold mobile phone accessories and worked directly with customers.
SELECTED ENGINEERING PROJECTS
High-Performance HTTP Proxy (Go)
• Developed a high-performance HTTP proxy service for efficient request routing and traffic processing with high-concurrency request handling and connection pooling.
Queue-Based Background Processing
• Implemented asynchronous task processing using queue-based background workers with Redis / RabbitMQ.
VoIP Integration Service
• Developed backend service integrating Asterisk telephony with CRM systems.
Image Tampering Analyzer
• Developed service detecting probability of image manipulation using Java and OpenCV.
EDUCATION & LANGUAGES
Education: Dnipro High School #137 - High School Diploma Languages: Ukrainian (Native), Russian (Fluent), English (Upper-Intermediate)