Staff Software Engineer - Platform Evolution

Staff Software Engineer - Platform Evolution Location: Bratislava, Slovakia Our clients are looking for a Staff Software Engineer to play a key role in shaping the technical direction, performance and long-term evolution of one of their core customer-facing comparison platforms. This is a hands-on Staff Engineer role combining frontend architecture, backend engineering and technical leadership. You'll be expected to influence engineering standards, drive architectural improvements, modernise legacy systems and help establish a scalable foundation for future growth. While this is a full-stack position, the majority of the day-to-day focus is on frontend architecture, application performance and customer experience, with approximately 60% frontend and 40% backend responsibility. The successful candidate will operate at Staff Engineer level, helping to set technical direction across the platform while remaining close to the code. Key Responsibilities Lead the technical evolution of a large-scale consumer-facing platform.Drive frontend architecture and performance improvements across React-based applications.Improve Core Web Vitals, rendering performance, caching strategies and overall user experience.Partner with Product and Engineering teams to shape technical roadmaps and platform direction.Identify and reduce technical debt through pragmatic modernisation initiatives.Conduct technical and architectural audits, translating findings into measurable engineering improvements.Define engineering standards, architectural principles and best practices.Mentor engineers and help raise technical capability across the wider team.Balance short-term delivery needs with long-term platform health and scalability.Remain hands-on through design reviews, code reviews and technical implementation. Required Experience Frontend Strong React experience gained within large-scale production environments.Experience designing frontend architecture rather than simply implementing features.Strong understanding of:Core Web VitalsRendering performanceState managementFrontend scalabilityBrowser performanceCaching strategiesPerformance monitoringExperience modernising legacy frontend applications.Backend Strong PHP engineering experience.Experience working with modern PHP frameworks such as Symfony, Laravel or similar.API design and integration experience.Experience with distributed systems, messaging and scalable application design.Experience working with cloud platforms such as AWS.LeadershipProven experience owning architectural decisions.Experience setting technical direction for teams or platforms.Experience mentoring engineers and improving engineering standards.Experience operating at Staff, Principal, Lead or Senior Engineer level with significant technical influence. Ideal Background Large-scale B2C websites or consumer platforms.High-traffic web applications.Digital marketplaces.Comparison platforms.Gaming platforms.Subscription businesses.E-commerce platforms processing significant traffic volume.