Sr. Software Development Engineer, Annapurna Labs

Sr. Software Development Engineer, Annapurna Labs

AWS Networking builds the infrastructure that powers every customer workload in the cloud. ENA Express is a next-generation EC2 networking feature that leverages the Scalable Reliable Datagram (SRD) protocol — developed by AWS — to deliver industry-leading networking performance: dramatically lower tail latency, higher bandwidth utilization, and consistent packet delivery  are looking for a Senior Software Development Engineer to join the ENA Express team.

You will design, build, and own features across the full ENA Express software stack:
Firmware on the Nitro-Card, user-space libraries, control plane components, and the performance analytics systems that help our customers get the most out of their network. This is high-ownership work — your code runs on a fleet of millions of EC2 instances, supporting customers who demand the absolute best from their network, including HPC clusters, large-scale ML training, financial services, and other latency-critical applications.

• Design and develop features across the AWS Networking software stack on Nitro Cards.
• Deep-dive into ENA Express and the underlying SRD protocol and L3/L4 networking to optimize packet delivery, reduce tail latency, and improve bandwidth utilization.
• Collaborate with hardware and firmware partners to define software/hardware interfaces and surface programmable capabilities to the software layer.
• Partner with EC2 platform and service teams to integrate ENA Express features into the broader AWS networking ecosystem.
• Mentor junior and mid-level engineers, lead design reviews, and champion engineering best practices across the team.
• Drive operational excellence: build observability, contribute to on-call health, and lead incident response and post-mortems.

We are a team of senior engineers with deep expertise in systems software, networking protocols, and EC2 infrastructure. Our work spans the full stack — from the Firmware on the driver Card, and NIC driver layer up through the EC2 control plane — and we collaborate closely with hardware, firmware, and platform partners. We care deeply about technical craft, operational quality, and each other’s growth.

• 5+ years of non-internship professional software development experience.
• Bachelor’s degree in computer science or equivalent.
• Background in systems programming (C / C++) in performance-critical, production environments.

• Experience in Linux and networking protocols, or experience in Linux OS and network troubleshooting.
• Experience in Linux and networking protocols, or experience in network protocols like DNS/DHCP/TCP and a strong analytical skill set, attention to detail, and effective communication abilities.
• Experience with virtualization (Hypervisors, VMware, Xen), or experience managing and troubleshooting network and experience in network protocols like DNS/DHCP/TCP.
• Experience working with software teams to tightly define the HW/SW interface, including control/status registers and error handling.

The base salary range for this position is  -  USD annually. Your Amazon package will include sign-on payments and restricted stock units (RSUs). Final compensation is determined based on experience, qualifications, and location. Amazon also offers comprehensive benefits including health insurance (medical, dental, vision, prescription, Basic Life & AD&D insurance and options for supplemental life plans), EAP, mental health support, medical advice line, flexible spending accounts, adoption and surrogacy reimbursement coverage, 401(k) matching, paid time off, and parental leave.

Amazon is an equal opportunity employer and does not discriminate on the basis of protected veteran status, disability, or other legally protected status.