Senior/Staff Frontend Engineer (Next.js/JavaScript) - Portugal Full Remote

Senior/Staff Frontend Engineer (Next.js/JavaScript) - Portugal Full Remote ABOUT THE OPPORTUNITY We’re looking for a Senior/Staff Frontend Engineer who has spent years building fast, reliable web products used by large audiences. You’ll own architectural decisions on complex Next.js applications. You’ll shape how the frontend scales, performs and gets tested, in a self-organized environment that trusts senior engineers to lead. PROJECT & CONTEXT You’ll join a product-driven digital company that builds high-traffic, web-native platforms for a global audience. Performance, SEO and accessibility are core to the product here. You’ll drive the architecture of large Next.js applications, including scaling within the App Router ecosystem. You’ll also push a strong testing culture that keeps production reliable. Teams work with a high degree of autonomy, and engineers own their decisions, their impact and how their careers grow. WHAT WE’RE LOOKING FOR (Required) 9+ years of professional software engineering experience, mainly on high-traffic, web-native products (SaaS, consumer web or large-scale digital platforms) Proven experience driving the architecture of complex Next.js applications (App Router, Next.js 13+) Deep understanding of rendering strategies: SSR, SSG, ISR and React Server Components (RSC), plus caching strategies Experience moving to or scaling within the App Router ecosystem Strong command of Vanilla JavaScript (ES6+), DOM manipulation and browser mechanics, and how the web works beneath the frameworks Hands-on focus on web performance: Core Web Vitals, SEO optimization and accessible, fast user interfaces A shift-left mindset with rigorous automated testing practices for production web apps Ownership, self-motivation and the ability to thrive in a self-organized environment Fluent English (written and spoken) NICE TO HAVE (Preferred) Experience building reusable frontend architecture, tooling and abstractions that speed up internal AI development across multiple teams Compensation: €2,800 – €3,650/month net, depending on experience and seniority level. Why HumanIT people stay (4.4 Glassdoor, 89% recommend) 15th month salary Health insurance covering your family Birthday off Mobility program for digital nomads Real work-life balance Full benefits: What it’s really like: Originally posted on Himalayas