Viktor Ivanisenko

Senior Back-End Developer with 7+ years of commercial experience building and optimizing high-load web applications and services using PHP, Laravel, PostgreSQL, ElasticSearch, and Docker. Strong background in API design, performance optimization, data analytics, and AI integrations. Experienced in leading backend development across multiple projects simultaneously, refactoring legacy systems, and improving system reliability, response times, and search performance.

Comfortable working in product teams, collaborating with frontend developers, and delivering scalable backend solutions aligned with business goals.

Back-End Developer at GoCows (2023-03 – Present)

Working on backend development for multiple projects, focusing on performance optimization and API design.

• Designed and implemented a campaign-based link management system in Laravel, supporting regional and device-based link routing, improving campaign flexibility and control.
• Built a parallel link health-check service (100 concurrent workers), reducing campaign link validation time by 90% compared to sequential checks.
• Implemented fallback validation for 403-restricted links via a third-party crawling service, increasing successful link verification rate by 27.6%.
• Developed a statistics aggregation pipeline using ElasticSearch, enabling fast redirection analytics and real-time reporting.
• Designed and delivered REST API endpoints for frontend consumption, improving data retrieval latency by 34.2%.

Back-End Developer at GoCows (2023-03 – Present)

Supplements store backend optimization and refactoring

• Took over an existing Laravel-based supplements store with performance and SEO issues affecting Google Search rankings.
• Refactored and optimized slow backend services, reducing average response time by 41.8%.
• Improved backend performance metrics to meet Google Search performance requirements, contributing to better indexing and visibility.
• Stabilized critical request paths and reduced timeout-related errors by 29.3%.

Back-End Developer / Team Lead at Quardex (2018-03 – 2023-01)

Technical lead for multiple projects with small team, managing development cycles, architecture, and production systems.

• Acted as technical lead for multiple projects with a small team.
• Planned development cycles, estimated tasks, and managed technical risks.
• Developed marketplaces and services using Laravel and integrated third-party APIs.
• Migrated PHP applications to Kubernetes, improving deployment stability.
• Refactored legacy codebases and maintained production systems.
• Developed and supported OpenCart-based online stores and custom WordPress plugins.
• Conducted regular code reviews to maintain quality standards.

Master of Science in Applied Physics – V. N. Karazin Kharkiv National University