Marek Víger

Backend engineer with 19 years of experience working on large-scale PHP platforms in production. I specialize in stabilizing and evolving legacy codebases under continuous production load, where full rewrites are not practical. I combine hands-on backend development with architectural decision-making, focusing on performance, reliability, and safe evolution in complex production environments.

Head of Engineering (hands-on) at Commander Services (2023-04 – 2025-12)

Slovak market leader in GPS telematics and fleet management. Responsible for technical direction and evolution of a large legacy PHP platform processing real-time telemetry data under high load and strict uptime requirements.

• Defined technical direction for gradual system evolution instead of large-scale rewrites.
• Led incremental upgrade of a ~2M LOC system from PHP 5.4 to PHP 7.4 without test coverage and without interrupting ongoing feature delivery.
• Introduced targeted safety-net tests for critical flows to reduce risk and enable safe refactoring in production.
• Reduced CPU load of the main system by ~50% through structural improvements and removal of bottlenecks.
• Reworked a critical telemetry processing service and introduced Symfony components into the codebase.
• Increased processing throughput by more than 4× by simplifying data flow and removing bottlenecks.
• Replaced noisy logging with structured, actionable signals and added health-check endpoints across services.
• Applied expand–contract database migration strategy to eliminate deployment-time schema risks.
• Gradually introduced Symfony components and Doctrine ORM to improve system structure, testability, and maintainability.
• Mentored senior engineers and established consistent architectural and coding standards across the team.
• Designed and led a senior-level PHP interview process focused on reasoning, system design, and trade-offs.

Senior Backend Developer / Architect at MageXo (2022-04 – 2023-03)

Adobe Commerce / Magento agency delivering large e-commerce solutions.

• Implemented a bidirectional SAP integration for an e-commerce platform (orders, inventory, pricing).
• Handled data synchronization between SAP and Adobe Commerce, addressing structural differences.
• Worked with complex product configurations, including bundling and multi-market setup (SI, HR, SK, CZ).
• Focused on maintaining data consistency and stability in production.

Chief Technology Officer at Marwin.Help (2021-04 – 2022-03)

IT support startup with chat, phone, remote desktop, and AR support channels.

• Refactored an MVP-stage Laravel monolith toward a cleaner domain-separated architecture.
• Introduced multi-tenant capabilities including currency, locale, and language isolation.
• Increased maintainability and testability of the platform.
• Helped prepare the codebase for parallel feature development.

Tech Lead → Chief Software Development Officer at WDS Solutions (2019-04 – 2021-04)

Custom software development company with multiple engineering teams and mixed technology stack.

• Worked on architectural direction across multiple projects and teams (PHP, Java, mobile), focusing on integration points and long-term maintainability.
• Designed a microservice-based platform for a customer portal used by 100k+ users (SPP-Distribúcia).
• Defined service boundaries for core domains including SSO, customer accounts, notifications, payments, and document generation.
• Led architectural reviews and helped establish consistent coding and design standards across teams.
• Introduced Docker-based development environments to reduce environment inconsistencies.
• Implemented GitLab CI pipelines and improved deployment reliability across projects.

Senior Developer at WebSupport (2017-06 – 2019-03)

Largest hosting provider in Slovakia with 100k+ customers.

• Supported evolution of a large legacy platform (~900k LOC) from PHP 5.3 to PHP 7.2 in production.
• Introduced Docker and CI/CD pipelines to improve deployment reliability and reduce environment issues.
• Helped define target architecture for CRM and order management systems and supported phased migration.

Tech Lead at Core4 (2015-10 – 2017-05)

Digital agency delivering solutions for enterprise clients such as Allianz, Orange, and ZSE.

• Introduced Git workflows, CI pipelines, and PHP frameworks into previously unstructured development.
• Standardized development practices and frontend build tooling.
• Mentored developers and represented the technical team in client communication.

Senior Developer at Costlocker SE (2015 – 2015)

Senior Developer at Piano Media (2012 – 2013)

Online Marketing Specialist at ESET (2009 – 2012)

IT Analyst at Partners Group SK (2008 – 2009)

Junior Developer at C.G.C., a.s. (2006 – 2008)

Computer Science in Computer Science – Constantine the Philosopher University, Nitra (2009 – 2011)

Applied Informatics in Applied Informatics – Comenius University, Bratislava (2008 – 2009)