Principal Software Engineer - Core 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 GitHub, Yelp, Paramount, and JetBlue. We're building a more trustworthy Internet. Come join us. Posting Open Date: Mar 25, 2026 Anticipated Posting Close Date*: April 6, 2026 Principal Software Engineer, Core Systems We are looking for a Principal Engineer who thrives on designing and navigating the path from today's systems architecture to tomorrow’s strategy and cares deeply about efficiency, security and scale. You’ll be deeply hands-on and technical, writing code, designing systems, shipping features, solving for scale and efficiency, guiding and mentoring teammates, and collaborating across the entire engineering organization. You will forge deep connections with other engineers, senior leadership, and partners across the company What You'll Do: Design and lead delivery of systems that drive our vision for scalability, security, performance and reliability in all the applications.. Provide and advocate for solutions to strategic and sophisticated technical problems, while influencing the organization with new ideas. Represent the Team in technical discussions across the organization. Help identify areas of opportunity in existing products and design solutions to support those efforts. Contribute and advocate for iterative improvements to both code and culture. Think strategically about the technical direction of the team’s software, in alignment to Fastly’s long term goals. Anticipate where and when systems will need to be adapted to meet our growth needs. Craft and articulate technical strategy via design documents. Sequence the technical building blocks required to enable durable innovation. Guide, share knowledge, and lead teams implementing cross functional systems. Enable outcome driven, collaborative discussions utilizing the deep technical knowledge of the teams you work with. Mentor and provide regular feedback to engineers. Lead by example. Be an active implementer and team member. Partner with senior engineering leaders to build and execute in both internal and open source contexts. Participate in an on-call rotation. What We're Looking For: SIgnificant domain-relevant software engineering experience (i.e., backend and distributed systems focus) with expertise in modern programming languages and tooling (the team works mostly in Golang). Most Principal Engineers at Fastly have at least 10+ years of related experience. Track record of choosing pragmatic over perfect solutions to ship features on-time and unblock cross-functional initiatives. Experience building efficient software at scale. Proven experience building internet facing systems that are safely operated A history of hands-on technical leadership building scalable and reliable software. Thoughtful, customer-driven approach to design and implementation. Excellent collaboration and communication skills; capable of building positive relationships with peers and leadership. Experience mentoring, guiding, and coaching team members and a passion for learning and sharing what you’ve learned with others. We’ll be super impressed if you have experience in any of these: Previous Fastly Experience Experience debugging large-scale distributed systems Experience with AWS ecosystem Experience with tools like Kubernetes, Terraform, Jenkins and Chef Work Hours: This position will require you to be available during core business hours and occasional nights and weekends as needed for on-call support. Work Loc ... (truncated, view full listing at source)