[Remote] Senior Site Reliability Engineer

Note: The job is a remote job and is open to candidates in USA. Mozilla's Thunderbird is a trusted open-source email application, and they are seeking a Senior Site Reliability Engineer to establish and maintain the infrastructure that users depend on. The role involves designing and developing CI/CD systems, diagnosing production incidents, and implementing improvements for system reliability.

Responsibilities

• Operate and evolve our EKS-based Kubernetes platform, supporting service migrations, platform improvements, and reliability initiatives
• Design and develop CI/CD systems supporting websites, services, and Thunderbird desktop releases, contributing to pipeline reliability and OIDC-based authentication across GitHub Actions workflows
• Write and maintain infrastructure in Pulumi and/or Terraform/OpenTofu across multiple AWS accounts
• Operate and evolve our observability stack (VictoriaMetrics, VictoriaLogs, Grafana, Vector) and partner with engineering teams to incorporate instrumentation and monitoring into service design
• Apply security-conscious infrastructure practices, including least-privilege IAM, secrets management via AWS Secrets Manager and External Secrets Operator, and network segmentation
• Diagnose and debug production incidents; drive root-cause analysis and post-incident improvements to prevent recurring problems
• Participate in on-call rotation and collaborate with SDEs and fellow SREs to ship, maintain, and monitor new builds and support service onboarding
• Contribute to runbooks, architecture documentation, and team processes

Skills

• 7+ years of experience in infrastructure, platform engineering, or site reliability roles, including hands-on production Kubernetes experience in workload operations, troubleshooting, and cluster management
• Hands-on experience with infrastructure-as-code on AWS using Terraform, OpenTofu, or Pulumi
• Security awareness in day-to-day infrastructure work: identity, least privilege, secrets hygiene, and network controls
• Demonstrated ownership mindset with the ability to proactively identify issues, drive work to completion, and communicate risks early
• Excellent async written communication skills; comfortable working with a geographically distributed team
• Ability to collaborate effectively with software engineers and non-engineering stakeholders to improve platform reliability and operational efficiency
• Ability to learn, evaluate, and responsibly use emerging technologies, including AI-enabled tools, to improve work processes
• Experience with GitOps workflows (ArgoCD or Flux)
• Familiarity with Keycloak or similar identity platforms (OIDC, SAML, federation)
• Knowledge of email protocols and/or experience operating email infrastructure (SMTP, IMAP)
• Prior work in or alongside an open-source community
• French, German, Japanese, or other language proficiency in addition to English

Benefits

• Fully remote work & schedule flexibility
• Company-provided laptop
• Annual bonus program
• Monthly remote work stipend
• Annual professional development stipend
• Industry conferences
• Company all-hands and team gatherings
• 24 days PTO per year (prorated)
• Your birthday
• Year-end company shutdown
• 9 wellbeing days
• Public holidays
• Other paid leave
• Quarterly wellbeing stipend for personal / family activities
• 401(k) / RRSP contributions
• Health, dental, & vision insurance
• Disability insurance
• Life insurance
• Employee assistance program
• Paid parental leave
• Paid sick days

Company Overview