Senior Front end Developer (React/TS) - SaaS Company

ABOUT TRUELOGIC We are a leading provider of nearshore staff augmentation services headquartered in New York. For over two decades, we’ve been delivering top-tier technology solutions to companies of all sizes, from innovative startups to industry leaders, helping them achieve their digital transformation goals. Our team of 600+ highly skilled tech professionals, based in Latin America, drives digital disruption by partnering with U.S. companies on their most impactful projects. Whether collaborating with Fortune 500 giants or scaling startups, we deliver results that make a difference. By applying for this position, you’re taking the first step in joining a dynamic team that values your expertise and aspirations. We aim to align your skills with opportunities that foster exceptional career growth and success while contributing to transformative projects that shape the future. OUR CLIENT A leading SaaS company that provides business management solutions for service-based businesses across North America. Their platform helps professionals streamline operations by managing customer relationships, estimates, projects, invoicing, payments, and other critical business workflows through web and mobile applications. Serving thousands of businesses, the company is continuously investing in modernizing its technology stack and enhancing the user experience across a suite of customer-facing products. JOB SUMMARY We're looking for a Senior Frontend Platform Engineer to join the Platform Services team responsible for the foundation that powers multiple React applications across the organization. This is not a feature-delivery role. Instead, you'll help design and evolve the frontend platform itself—building reusable infrastructure, improving architecture, establishing engineering standards, and solving complex cross-application challenges around state management, authentication, performance, observability, resilience, and developer experience. The ideal candidate enjoys working on platform engineering problems, understands frontend architecture at scale, and can confidently explain technical tradeoffs backed by real production experience. RESPONSIBILITIES - Design and implement scalable frontend architecture used across multiple applications. - Build reusable platform capabilities for authentication, networking, routing, state management, and error handling. - Improve application performance through profiling, code splitting, lazy loading, bundle optimization, and rendering optimizations. - Design resilient frontend systems that properly handle authentication flows, session management, token refresh, offline behavior, retries, and request cancellation. - Build maintainable API communication layers, request interceptors, caching strategies, and error handling patterns. - Improve frontend observability through logging, monitoring, Real User Monitoring (RUM), and production diagnostics. - Drive testing strategy across unit, integration, and end-to-end testing while improving overall application reliability. - Champion accessibility, performance, scalability, and engineering best practices across the frontend ecosystem. - Participate in architecture reviews, technical design discussions, and modernization initiatives. - Mentor engineers through code reviews and architectural guidance. QUALIFICATIONS AND JOB REQUIREMENTS - 5+ years of professional Frontend Engineering experience building large-scale React applications. - Expert knowledge of React, TypeScript, JavaScript (ES6+), HTML5, and CSS3. - Deep understanding of frontend architecture, component design, and application scalability. - Strong experience designing complex state management solutions using Redux Toolkit, TanStack Query, or similar technologies. - Experience building robust authentication and authorization flows, including JWT, cookies, session management, token refresh, and secure client-side storage. - Strong understanding of API architecture, request lifecycle management, i…