Senior Software Engineer, Backend

Senior Software EngineerQXO is a leading distributor and installer of building products serving an $800 billion market. The company's mission is to modernize the building products industry through advanced technology and a best-in-class customer experience. QXO is North America's largest distributor and installer of insulation, the second-largest distributor of roofing products, the second-largest publicly traded distributor of lumber and building materials, and the largest distributor of waterproofing products. The company is targeting $50 billion in annual revenue within the decade through accretive acquisitions and organic growth.As a Senior Software Engineer on the QXO eCommerce team, you will lead the design, development, and operation of foundational commerce services. You will own complex systems from ideation through launch and drive long-term architectural evolution. You'll collaborate across engineering, product, and design teams to build secure, reliable, and extensible services and user interfaces that serve millions of users across web and mobile platforms.This role is ideal for engineers who are highly technical, customer-obsessed, and comfortable working in fast-paced environments with high ambiguity and high ownership.Key ResponsibilitiesDesign, build, and operate eCommerce servicesDesign and implement scalable, low-latency systems that meet performance and security requirementsBuild intuitive and performant user interfacesContribute to shared design system and front-end architectureCollaborate with cross-functional teams to develop end-to-end solutionsWrite clean, efficient, and testable codeContribute to shared libraries and platform components.Lead design, architecture and code reviews.Continuously improve operational excellence and system reliabilityMentor junior engineers and shape engineering best practices.Qualifications & Skills5+ years of hands-on coding experience3+ years building scalable, distributed systems using object-oriented programming languages (Java, Kotlin, Go, etc.)Experience with modern front-end technologies and frameworks such as React, Next.js, or TypeScriptStrong knowledge of data structures, algorithms, system design, and concurrencyExperience building and developing large-scale reliable distributed systems.Experience designing, launching, and maintaining production systems in a cloud-native environment (e.g., GCP, AWS)Experience leading architectural designs and mentoring other engineersBachelor's degree in computer science, engineering, or equivalentStrong verbal and written communication skillsPreferred Qualifications:Experience building commerce, checkout, identity, or personalization services at scaleExperience building responsive, accessible, and performant UIs using front-end or mobile frameworks such as React NativeFamiliarity with AI/ML systems, including model inference pipelines, data labeling infrastructure, or real-time decisioningExperience with experimentation frameworks, recommendation engines, or search platformsExperience working with CI/CD pipelines, observability tools, and performance tuningExperience in Marketing or Ad TechMS or Ph.D.What You'll EarnBase pay range: $138,000 - $235,000Annual performance bonusLong term incentive (equity/stock)401(k) with employer matchMedical, dental, and vision insurancePTO, company holidays, and parental leavePaid Time Off/Paid Sick Leave: Applicants can expect to accrue 15 days of paid time off during their first year (4.62 hours for every 80 hours worked) and increased accruals after five years of service.Paid training and certificationsLegal assistance and identity protectionPet insuranceEmployee assistance program (EAP)QXO is an Equal Opportunity Employer. We value diversity and do not discriminate on the basis of race, color, religion, gender or sexual orientation, national origin, age, disability, or any other protected status.