Role: Network Development Engineer - Core & Backbone Teams (All Levels) Location: Palo Alto, Atlanta, Hillsboro (US) or Dublin (EU) US Salary Range: $108,000 to $259,000 + Equity _ Who We Are: X serves our community of users and customers by working tirelessly to preserve free expression and choice, enable limitless interactivity, and build a marketplace that drives the economic success of all its participants. X is looking for talented Network Development Engineers to join its Core & Backbone Networking teams, bringing deep expertise in building and operating global infrastructure-from hyperscale data centers to a highly connected edge. You'll help develop world-class network products that power X's worldwide reach. Who You Are: You take pride in designing and building highly scalable, resilient, and performant infrastructure-and in rigorously testing every layer of it. Whether deploying networks that support 100K+ servers or architecting global backbone and edge solutions, you bring strong technical leadership, deep systems thinking, and a passion for clean design. You're at your best in collaborative environments, thrive on cross-functional problem-solving, and are comfortable owning critical decisions. You communicate clearly, operate with high ownership, and bring energy to multi-disciplinary technical teams. What You'll Do: * Design, scale, and manage datacenter and backbone network infrastructure * Lead architecture reviews and contribute to evolving network design * Deploy and optimize a global multi-vendor, multiprotocol environment * Perform qualification and validation of hardware and software * Build fault-tolerant systems via proactive monitoring and anomaly detection * Drive incident resolution and participate in a 12x7 on-call rotation * Correlate network events, diagnose root causes, and implement long-term fixes * Develop operational procedures and resilient remediation strategies * Advance automation frameworks to accelerate deployment and reduce risk Qualifications: * B.S. in network engineering or a related technical discipline, or equivalent experience * Expert-level knowledge of large-scale networking including platforms, topologies, and protocols like BGP, OSPF, or IS-IS * Proven track record in solving complex networking challenges and driving cross-team execution * Deep understanding of data center networking at scale, including Clos fabrics and BGP-based designs * Hands-on experience with backbone, edge, and application-layer networking * Proficiency with Unix/Linux environments and scripting (Python preferred) * Hunger to learn new networking protocols, vendor systems, and languages as needed