Senior Site Reliability Engineer

We are looking for an experienced Site Reliability Engineer (SRE) to contribute to the development, enhancement, and scalability of our CDN and Web Application Firewall (WAF) product. You will focus on the delivery of new features, performance optimization, and security control improvements across our edge stack. This position calls for expertise in Nginx/OpenResty, Lua, C/FFI module development, eBPF, Linux networking, and infrastructure-as-code tooling.

Responsibilities

• Design, implement, and ship features and improvements for our CDN and WAF edge stack
• Develop and maintain Lua code running in Nginx/OpenResty, and build high-performance C modules or FFI bindings as needed
• Implement packet- and kernel-level observability and filtering using eBPF (including XDP/eBPF tracing for telemetry and enforcement)
• Tune and troubleshoot high-volume Nginx deployments for latency, throughput, and memory usage
• Define, author, and maintain WAF rule logic, request/response inspection, and mitigation workflows
• Build automation for deployment and configuration using Infrastructure as Code tools (Ansible, Puppet, Terraform, or similar)
• Work with networking protocols and operational requirements of a CDN, including BGP, anycast, TCP/IP stack, load balancing, and connection handling
• Create and run performance/load tests, fuzzing tests, and security tests; profile and optimize hotspots
• Produce clear design documentation and runbooks, and hand over completed work to operations. Participate in code reviews and mentor engineers
• Collaborate with product, security, and SRE teams to align feature work with product goals and SLAs

Requirements

• 5+ years of production experience in Linux systems engineering, networked services, or edge infrastructure
• Strong hands-on experience with Nginx and Lua (ngx_lua/OpenResty), including writing Lua modules for request processing
• Familiarity with or experience in building native C modules or FFI bindings used by Nginx/Lua; comfortable with libc, POSIX APIs, and building/packaging C extensions
• Practical experience with eBPF (tools, BCC/libbpf, XDP) for telemetry, filtering, or tracing
• Deep knowledge of networking and TCP/IP internals, load balancing, and CDN operational patterns. Familiarity with BGP and anycast is a plus
• Experience with Web Application Firewalls, whether appliances, services, or software, and a strong understanding of their capabilities
• Solid Linux kernel and userland troubleshooting skills, including proficiency with tools such as perf, tcpdump/Wireshark, strace, and SystemTap
• Experience with Infrastructure-as-Code and configuration management tools (e.g., Ansible, Puppet, Chef, Terraform, or similar)
• Experience in deploying and maintaining WAF rulesets and policies, with an understanding of OWASP Top 10 risks and common web attack patterns
• Proficiency with testing and benchmarking tools (e.g., wrk, ab, locust, etc.) and CI/CD pipelines
• Excellent communication skills; able to work independently and collaborate effectively with distributed teams
• English language proficiency at an Upper-Intermediate level (B2) or higher

Nice to have

• Prior experience in building or operating CDNs or edge platforms
• Familiarity with web security tooling, such as ModSecurity, or other WAF platforms
• Experience with container workflows and edge deployment (e.g., Docker, HashiCorp Nomad)
• Exposure to cloud providers’ networking (AWS, GCP, or Azure) and hybrid edge deployments
• Familiarity with observability stacks, such as Prometheus, Grafana, and ELK/EFK
• Experience in cross-compiling or packaging modules for multiple Linux distributions
• Experience programming in Lua and C, with familiarity using LuaJIT and the Lua FFI for native, high-performance integrations

We offer

• CONTINUOUS UPSKILLING, LEARNING & DEVELOPMENT
  • Diversity of tasks and projects
  • Assessment center for objective review of competency level
  • Personal development plan
  • Mentoring programs and leadership development
  • Certification and professional development support
  • Access to learning platforms including more than 2,500 internal courses and the LinkedIn Learning library with 20,000+ courses
  • English courses taught by certified teachers
• CORPORATE BENEFITS
  • Extra leave days
  • Referral bonuses
• COMPENSATION PACKAGE
  • Competitive compensation paid in USD
  • Regular salary and performance reviews
• MEDICAL & HEALTHCARE
  • Private health insurance
  • Well-being events
• WORKING ENVIRONMENT
  • Recreation areas and kitchens
  • Tea, coffee, and snacks
  • Well-being events
  • Sports equipment and game consoles
  • IT Equipment
  • Microsoft's Software Assurance Home Use Program (HUP)

EPAM is a leading global provider of digital platform engineering and development services. We are committed to having a positive impact on our customers, our employees, and our communities. We embrace a dynamic and inclusive culture. Here you will collaborate with multi-national teams, contribute to a myriad of innovative projects that deliver the most creative and cutting-edge solutions, and have an opportunity to continuously learn and grow. No matter where you are located, you will join a dedicated, creative, and diverse community that will help you discover your fullest potential.