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Software Engineer - EOS Routing Team

Arista Networks

Arista Networks

Software Engineering
Dublin, Ireland
Posted on Tuesday, September 19, 2023

Company Description

Arista Networks is the leader in software driven networking solutions for today’s largest Data Center (DC), Cloud, Internet/WAN, Service Provider (SP) and Campus environments. Arista has over 7500 customers ranging from the largest cloud providers, to healthcare, government, carrier, finance, education, and production web/SaaS companies. Arista's products are the foundation underpinning much of modern society's operations.

Arista has ambitious plans and an unprecedented opportunity for growth and we are looking for many more engineers and designers to join us in building and innovating the world's networks. Arista is a profitable, publicly quoted company with revenues of over $2B with a culture of invention, quality, respect, and fun.

One of the many attractions of joining Arista is that right from the top, Arista is an engineering company. The founders and engineering managers are all engineers who understand good software engineering and the importance of doing things right.

Our management structure is flat and lightweight. Software engineering is run by software engineers who are in charge of delivering features from concept through to completion. We put a premium on building quality software and using automated testing. No part of the company is off-limits, meaning that our engineers have the chance to work in many different areas over time.

Arista today is one of the fastest-growing companies in the industry. Arista has disrupted the market with two significant innovations:

  1. Arista’s principle invention is an advanced network operating system, Arista EOS® (Extensible Operating System). Based on open standards, delivering high reliability and unique programmability at all system levels and offering a data-driven network platform that automates IT workflows, provides network-wide visibility, and enables rapid problem resolution.
  2. Arista’s other key innovation is the exclusive use of best-in-class merchant silicon that enables open standards-based networking with rapid time-to-market. Notably, Arista’s merchant silicon strategy delivers state-of-the-art platforms at a faster time to market enabled by technology advances associated with Moore’s Law. In contrast, legacy approaches are built on custom ASICs coupled with monolithic software resulting in proprietary platforms and increased costs.

Arista’s engineering team started from a blank sheet of paper to architect an entirely new networking operating system. Arista’s unique architecture is based on three guiding principles:

  1. State orientation
  2. Open standards-based approach
  3. Single software image consistency

1) State Orientation for publish-subscribe communication

State Orientation uses a unique multi-process state-sharing architecture that separates state information from protocol processing and application logic with a central database shared by diverse applications. Both system state and data are stored in the system database where data is accessed via an automated publish/subscribe model. This distinct design principle provides module independence, self-healing resiliency, and multi-process software stability. It is an elegant distributed systems solution applied holistically right across the network.

This contrasts with the decades-old legacy approach of many competitors that uses extensive inter-process communications (IPC), a shared memory bus, or a complex message passing framework to communicate across the system components.

2) An Open Approach

Arista took to heart the lessons of the open-source world and built EOS on top of an unmodified Linux kernel, maintaining full, secured access to the Linux shell and utilities. It is notable that it is the same Linux OS that Arista’s customers run in their data centers and on their servers. This foundational methodology enables EOS to preserve the security, feature development, and tools of the Linux community, unlike legacy approaches where the original OS kernel is either modified or based on older, less maintained versions. By adhering to open source Linux, EOS also natively supports Linux containers and virtual machines, simplifying the deployment of new services and enhancing DevOps practices.

3) A Single Image

Arista’s third and crucial guiding principle is to provide a single software image that runs across all products in various packaging forms - physical platforms, virtual machines, and containers. The EOS single image uses the same source code, and the same version of the software released across the entire portfolio of switches and routers, thus improving network testing and reliability while reducing the complexity and cost of network operations.

This approach is a large differentiator to legacy vendors who use multiple operating systems with numerous images to implement a siloed network. Managing these multiple software images with quality control testing or new features testing multiplies operational costs. In contrast, when Arista releases a new software version, customers merely deploy a single image network-wide.

In addition, having a single image improves automation workflows by allowing DevOps tools, such as Ansible or Terraform, to work across all Arista devices with a single integration. Using these integrations, operators can establish Continuous Integration (CI) pipelines that build, test, and deploy network configurations across the entire data center with increased speed and reliability.

Job Description

The EOS Routing team is a global team responsible for developing IP routing protocols (BGP, OSPF, IS-IS, etc) and MPLS signalling protocols (LDP, RSVP), and DC and SP technologies like Segment Routing and EVPN. You will be responsible for

  • understanding and writing functional specifications based on requirements from customers, product managers and field engineers
  • owning all aspects of development and delivery of software
  • building the highest quality networking features
  • implementing automated tests
  • working with customers to troubleshoot and resolve problems in their networks


Basic qualifications

  • Bachelor's/Master's degree in Engineering
  • 3+ years of experience working as a Systems Software Development Engineer
  • Proficiency in C/C++ and Python programming languages
  • Strong communication skills and the ability to work in a team environment

Preferred qualifications

  • Experience working through the complete software development life cycle right from requirements gathering to delivering the fully developed feature
  • Software development experience with Linux
  • Strong software debugging skills especially in embedded systems
  • Experience in networking technologies such as BGP, IS-IS, LDP, OSPF, RSVP, EVPN, Segment Routing, VPWS, VPLS, LDP Pseudowires

Additional Information

Hiring in Locations: Dublin Ireland, Kraków Poland

All your information will be kept confidential according to EEO guidelines.