[Skip to main content](#main-content) [OpenNash Jobs](https://jobs.opennash.com/) [Hiring report](/reports/hiring/) · [All Arista Networks jobs](https://jobs.opennash.com/companies/arista-networks/) · [Search jobs](/search/) Arista Networks · Nashua, NH # Lead Software Engineer, Packet Forwarding Nashua, NH, United States Full-time Manager or lead Software Engineering Listed on Arista Networks’s official careers site. Posted September 11, 2026. Check that it is still open and apply there. [Apply on Arista Networks’s careers site →](https://jobs.smartrecruiters.com/AristaNetworks/744000149104294-lead-software-engineer-packet-forwarding) [OpenNash Jobs](https://jobs.opennash.com/) / [Arista Networks](https://jobs.opennash.com/companies/arista-networks/) / Lead Software Engineer, Packet Forwarding ## Job description Who You’ll Work With As a Senior/Lead PFE software engineer, you will collaborate and work with customers, product management and engineers to design and build novel packet forwarding features in EOS that help networks run effectively and efficiently. You will need to understand the packet forwarding architecture in depth and figure out how to apply it optimally to solve customer problems. You will design the packet forwarding flow, design data structures and algorithms to render the packet forwarding state used by the forwarding engine for efficiency and scale, and tie it all together with the higher layers. In this role, you will get to confront complex, multi-dimensional problems such as “Upgrade software on a switch with no more than a few milliseconds of downtime” or “Render a routing table with >1M routes into the forwarding path on a router with a hundred forwarding chips” that are open ended, challenging, fun and require strong problem solving skills. Arista Software Engineering roles demand a strong and broad software engineering background. While the primary focus area for this role is packet forwarding, the role will cover all aspects of software development spanning the addition of new features, debugging problems and fine tuning code for scalability and performance. You will own your projects from definition to deployment and customer interactions, and you will be responsible for the quality of everything you deliver. Arista Software Engineering prides itself on a supportive and growth oriented culture, which provides opportunities for increased responsibilities, and to expand expertise into new areas. ### What You’ll Do Interface with customers and product management to define packet forwarding features and solutions. Architect, design and manage the development of these features. Develop and maintain features using C, C++ and Python, review and contribute to functional and design specifications. Build automated tests and test infrastructure to test the features. Provide technical leadership across features, projects and tools. Work with Customer Support Engineers and customers to analyze, mitigate and fix problems in customer networks. Work with the System Test Engineers to analyze problems found in their tests and provide fixes for those problems. Mentor new and junior engineers to bring them up to speed in Arista's software development environment. ## Qualifications BS Computer Science/Electrical Engineering/Computer Engineering + 6 years experience, or MS Computer Science/Electrical Engineering/Computer Engineering + 4 years experience, or Ph.D. in Computer Science/Electrical Engineering/Computer Engineering + 3 years experience, or equivalent work experience Expert knowledge of C or C++ and Python. - Knowledge of UNIX or Linux Experience working with packet forwarding chips and pipelines Understanding of IP networking and/or distributed systems Understanding and ability to apply software engineering principles - Strong problem solving and software troubleshooting skills - Demonstrated technical leadership, strong communication skills, and the ability to work in a small team environment - Ability to design a solution and implement features independently #LI-SZ1 ## At a glance - Posted by the employer: Sep 11, 2026 - First seen by OpenNash: Oct 10, 2026 - Last checked: Oct 17, 2026 - Listed for: 36 days - Location: Nashua, NH, United States - Employment type: Full-time[Apply on Arista Networks’s careers site →](https://jobs.smartrecruiters.com/AristaNetworks/744000149104294-lead-software-engineer-packet-forwarding) ## More jobs at Arista Networks ### [BIOS Senior/Lead Software Engineer](https://jobs.opennash.com/companies/arista-networks/jobs/0eee0936a6bb34d8b2f8/) Nashua, NH, United States ### [BIOS Software Engineer](https://jobs.opennash.com/companies/arista-networks/jobs/1c3fdc7955de4c42a730/) Nashua, NH, United States ### [Diagnostics Software Engineer](https://jobs.opennash.com/companies/arista-networks/jobs/bcb2a2b16f9173d05aea/) Nashua, NH, United States ### [Lead Software Engineer, Network Systems](https://jobs.opennash.com/companies/arista-networks/jobs/97067952f2bff82eae6a/) Nashua, NH, United States ### [Lead Software Engineer, Physical Network Layer](https://jobs.opennash.com/companies/arista-networks/jobs/fe424ae797b8d597da29/) Nashua, NH, United States ## Similar jobs at other companies ### [Senior Software Engineer - Packet Forwarding Software](https://jobs.opennash.com/companies/hewlett-packard-enterprise/jobs/f223a218928c4a24c202/) Hewlett Packard Enterprise · Sunnyvale, California, United States of America ### [Software Engineer/Sr. Software Engineer](https://jobs.opennash.com/companies/microsoft/jobs/194f63de625f0dce008e/) Microsoft · United States, Washington, Redmond ### [Senior Software Engineer/Software Engineer II](https://jobs.opennash.com/companies/microsoft/jobs/533e77af5ee9c7fa5145/) Microsoft · United States, Washington, Redmond ### [Software and Data Engineer - Software Engineer III- Agentic Pricing](https://jobs.opennash.com/companies/jpmorganchase/jobs/1adbc421af4b64b8e0c5/) JPMorganChase · Jersey City, NJ, United States ### [Software Developer/Software Engineer in Test](https://jobs.opennash.com/companies/general-dynamics/jobs/229bce1af89aceaed99c/) General Dynamics · Falls Church, VA, US OpenNash lists jobs from employers’ own careers sites and does not handle applications. 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