Senior Principal Engineer - Edge Systems

Fastly helps people stay better connected with the things they love. Fastly’s edge cloud platform enables customers to create great digital experiences quickly, securely, and reliably by processing, serving, and securing our customers’ applications as close to their end-users as possible — at the edge of the Internet. The platform is designed to take advantage of the modern internet, to be programmable, and to support agile software development. Fastly’s customers include many of the world’s most prominent companies, including Vimeo, Pinterest, The New York Times, and GitHub.

We're building a more trustworthy Internet. Come join us.

Posting date: Aug 12, 2025

Anticipated Posting Close Date*: Sep 10, 2025

*Job posting may close early due to the volume of applicants.

 

Senior Principal Software Engineer - Edge Systems

The Edge Systems Team develops software that interacts with the full systems stack of Fastly’s infrastructure, from the kernel up to core systems software. Projects range from implementing new protocols, optimizing kernel-userspace communication, routing among the edge nodes, designing distributed systems, and more. We expect this position to focus on enhancing our overall core edge systems with respect to efficiency, performance, and resilience. We are looking for a Senior Principal Software Engineer passionate about applying their talents to make the Internet fast and reliable.

What You'll Do

• Lead full lifecycle projects from architecture & design to deployment in support of Fastly’s edge systems.
• Write, test, and deploy C, Rust, and Go code.
• Enhance, maintain and optimize network protocols such as TCP and QUIC
• Work across layers from the Linux kernel to the core edge systems to control planes.
• Collaborate with cross-functional teams and stakeholders to shape a clear technical roadmap - prioritizing key initiatives and proactively identifying and mitigating risks - to deploy, support, troubleshoot, and deliver features to customers
• Contribute to open source projects such as h2o and picotls
• Mentor and support the professional growth of engineers, fostering a culture of respect, knowledge sharing, innovation, and collaboration within the team

What We're Looking For

• Proven ability to design & implement reliable, scalable, low latency systems. Most Senior Principal Engineers at Fastly have at least 12 years of domain relevant engineering experience. 
• Significant production experience with coding in C, C++, and/or Rust 
• Experience with Linux systems and network programming
• Hands-on experience in building distributed infrastructure and maintaining it over time
• Advanced knowledge of Linux as a development environment: git, compilers
• Excellent written and verbal communication skills, with the ability to produce clear and comprehensive documentation
• A collaborative mindset with experience working across cross-functional teams, fostering a culture of respect, knowledge sharing and innovation
• Proven ability to mentor and support the growth of engineers, both within a specific area of expertise and more broadly

We value a variety of voices, so this is not a laundry list. It would be an added bonus if you have experience in ANY of these:

• Web/Internet protocols such as TCP, HTTP, TLS, DNS, QUIC
• Understanding of datapath mechanisms such as eBPF and DPDK
• Ability to systematically profile and benchmark complex cross-layer distributed systems
• Understanding of how customers will interact with features you develop
• Comfortable working in a geographically distributed team and highly available environments

 

Work Hours:

This position will require you to be available during core business hours and occasionally nights and weekends as required for on call support.

 

Work Location(s) & Travel Requirements: 

This position is open to Hybrid Work Locations only. The preferred locations for this position are:

• London, UK
• San Francisco, CA
• Denver, CO

Fastly currently embraces a largely hybrid model for most roles which allows employees flexibility to split their time between the office and home.  We are not considering remote applicants at this time.

This position may require travel as required by your role or requested by your manager.

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