Senior Backend Software Engineer (APIs)

Overview

Some of the largest sites on the internet trust Fastly to keep them safe. The Security Products Console team owns the public-facing interface they use to do it - configuring Next-Gen WAF, DDoS protection, Bot Management, and the products we're building next.

Our APIs meet critical business needs. Customers deploy them during active attacks, automate them through Terraform and CI/CD, and build entire security workflows on top of them. We're hiring as the API surface scales for new product launches and a growing developer ecosystem. You'll be one of the engineers shaping what that surface looks like for the next several years.

What You'll Do

• Design, ship, and own public-facing APIs and backend services in Go - from technical proposal & design docs through implementation, testing, and production rollout and on-call support.
• Use AI coding agents as part of your daily workflow.
• Partner with frontend engineers, product managers, and security researchers to ship the customer experience end-to-end.
• Take ambiguous or broadly-scoped problems and turn them into well-defined technical plans that the team can execute on.
• Author design and architectural documents and use them to drive alignment across engineering and product teams.
• Collaborate with internal platform teams, product managers, and stakeholders across the organization to understand their needs and deliver impactful solutions.
• Consider stability, performance, and scalability in your designs and in the guidance you provide to the team.
• Mentor and grow other engineers on the team through code review, pairing, and technical leadership.
• Participate in an on-call rotation.

What We're Looking For

• Hands-on experience designing and building reliable, large-scale backend systems (5+ years of relevant experience).
• 5+ years shipping production Go as your primary language.
• 3+ years on public APIs with external consumers (experience shipping breaking changes, writing deprecation notices).
• Proven track record driving projects end-to-end (multi-week effort from design doc through post-launch).
• Good judgement on RESTful API design: resource modeling, versioning, idempotency, error semantics, pagination, OpenAPI.
• Thoughtful design for downstream API consumers (external customers, support engineers, frontend teammates).
• Experience with testing and observability practices.
• Experience using AI coding agents heavily in daily workflows.

Nice to Have

• Built or operated security products (WAF, bot, DDoS, app security).
• Working knowledge of auth at API scale (RBAC, OAuth, JWT, SAML).

Work Hours & Location

• Available during core business hours (Pacific Time) and occasional nights and weekends for on-call support.
• Preferred office locations: San Francisco, CA or Denver, CO (Hybrid model; exceptionally qualified remote candidates within US Pacific and Mountain time zones may be considered).

Interview Policy

To ensure a fair and equitable interview process, the use of AI technologies—including real-time transcription tools, automated scripts, AI copilots, or external assistants—is strictly prohibited during the interview process unless explicitly authorized by the company in advance.