> Markdown version of [/jobs/ext/2869619-lead-pfe-software-engineer](https://www.wearedevelopers.com/jobs/ext/2869619-lead-pfe-software-engineer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Lead PFE software engineer - **Company:** Arista Networks - **Location:** United States - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** C (Programming Language), Automation of Tests, Unix, C++ (Programming Language), Computer Engineering, Data Structures, Software Debugging, Linux, Distributed Systems, Integrated Development Environments, Internet Protocol, Python (Programming Language), Software Engineering, System Testing, Software Troubleshooting, Information Technology - **Published:** September 12, 2026 - **Apply:** https://startup.jobs/lead-software-engineer-packet-forwarding-arista-networks-10029552 ## About the Role * 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 ## Description 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. ## Related Videos - [Fingerboard to Keyboard: Transposing One Profession to Another](https://www.wearedevelopers.com/videos/868-fingerboard-to-keyboard-transposing-one-profession-to-another) - [WeAreDevelopers LIVE - Node and Package Security](https://www.wearedevelopers.com/videos/2138-wearedevelopers-live-node-and-package-security) - [How To Test A Ball of Mud](https://www.wearedevelopers.com/videos/173-how-to-test-a-ball-of-mud) - [Docker network without Docker](https://www.wearedevelopers.com/videos/1418-docker-network-without-docker) - [An Applied Introduction to eBPF with Go](https://www.wearedevelopers.com/videos/1075-an-applied-introduction-to-ebpf-with-go) - [Into the hive of eBPF!](https://www.wearedevelopers.com/videos/1199-into-the-hive-of-ebpf) ## Related Articles - [How We Built a Worry-Free System That Runs for 10+ Years – And What We’d Do Again](https://www.wearedevelopers.com/magazine/751-how-we-built-a-worry-free-system-that-runs-for-10-years-and-what-we-d-do-again) - [How Much FAANG Companies Actually Pay Software Engineers in 2025](https://www.wearedevelopers.com/magazine/230-how-much-faang-companies-actually-pay-software-engineers-in-2025) - [10 Highest Paying Programming Languages 2025](https://www.wearedevelopers.com/magazine/150-10-highest-paying-programming-languages-2025) - [Top Characteristics of a Software Engineer](https://www.wearedevelopers.com/magazine/166-top-characteristics-of-a-software-engineer) - [The Best X (Twitter) Accounts for Developers](https://www.wearedevelopers.com/magazine/294-the-best-x-twitter-accounts-for-developers) - [Best Paying Jobs in Technology](https://www.wearedevelopers.com/magazine/256-best-paying-jobs-in-technology)