QXO is a leading distributor and installer of building products serving an $800 billion market. The company is modernizing the building products industry through advanced technology and a best-in-class customer experience. We are seeking a Staff Software Engineer - Backend to design, build, and operate scalable eCommerce services and to develop scalable, low-latency systems with strong security. You will design and implement scalable architectures, build intuitive and performant user interfaces, contribute to shared libraries and platform components, and collaborate with cross-functional teams to deliver end-to-end solutions. Responsibilities include leading design reviews, mentoring junior engineers, and driving engineering best practices. Qualifications: 5+ years of hands-on coding; 3+ years building scalable distributed systems using languages such as Java, Kotlin, or Go; experience with modern front-end technologies (React, Next.js, TypeScript); strong knowledge of data structures, algorithms, system design, and concurrency; experience deploying production systems in cloud environments (GCP, AWS); ability to lead architectural designs and guide other engineers; Bachelor's degree in computer science or engineering or equivalent. Preferred: experience building commerce, checkout, identity, or personalization services; experience with React Native; familiarity with AI/ML systems, experimentation frameworks, CI/CD, observability, and performance tuning; exposure to marketing or ad tech; MS or PhD. Compensation includes base pay range $138,000 - $235,000, annual bonus, long-

QXO is a leading distributor and installer of building products serving an $800 billion market. The company is modernizing the building products industry through advanced technology and a best-in-class customer experience. We are seeking a Staff Software Engineer - Backend to design, build, and operate scalable eCommerce services and to develop scalable, low-latency systems with strong security. You will design and implement scalable architectures, build intuitive and performant user interfaces, contribute to shared libraries and platform components, and collaborate with cross-functional teams to deliver end-to-end solutions. Responsibilities include leading design reviews, mentoring junior engineers, and driving engineering best practices. Qualifications: 5+ years of hands-on coding; 3+ years building scalable distributed systems using languages such as Java, Kotlin, or Go; experience with modern front-end technologies (React, Next.js, TypeScript); strong knowledge of data structures, algorithms, system design, and concurrency; experience deploying production systems in cloud environments (GCP, AWS); ability to lead architectural designs and guide other engineers; Bachelor's degree in computer science or engineering or equivalent. Preferred: experience building commerce, checkout, identity, or personalization services; experience with React Native; familiarity with AI/ML systems, experimentation frameworks, CI/CD, observability, and performance tuning; exposure to marketing or ad tech; MS or PhD. Compensation includes base pay range $138,000 - $235,000, annual bonus, long-