Senior Software Engineer

(Distributed Systems | WebSockets | Cloud-Native Scale)

We are seeking a Senior Load & Performance Engineer to own performance engineering for high-scale, real-time, event-driven systems operating at production traffic levels.

This role is deeply hands-on and architecture-adjacent. You will design and execute distributed load tests at massive concurrency (100K+ WebSocket connections), build scalable performance frameworks, and ensure our systems hold up during peak, revenue-critical sporting events.

You’ll operate in a cloud-native, Kubernetes-based environment, using K6, Testkube, GitHub Actions, and AWS-native security patterns to run production-grade performance tests safely, securely, and repeatably.

This is not a script-runner role. This is performance engineering at scale.

• Own end-to-end performance testing strategy for real-time and transactional systems
• Design and execute load, stress, spike, endurance, and soak tests in production and pre-prod environments
• Define performance baselines, SLOs, and regression thresholds
• Drive shift-left performance validation during design and development

• Design distributed WebSocket load tests supporting 100,000+ concurrent connections
• Architect parallel test execution across multiple Kubernetes pods using CI/CD orchestration
• Model realistic traffic patterns for:
  • Sportsbook odds updates
  • Bet Builder workflows
  • Real-time market data streams
• Prevent resource exhaustion issues (OOM, CPU saturation) through smart test distribution and profiling

• Build and evolve K6-based performance frameworks
• Integrate tests into GitHub Actions pipelines with configurable parallelism
• Use Testkube for Kubernetes-native test execution
• Implement dynamic test profile generation (no-code-change test tuning)
• Enable fast iteration during live events without redeploying code

• Implement production-grade security for performance tests using:
  • AWS SSM Parameter Store
  • CSI Secrets Store Driver
  • IAM Roles for Service Accounts (IRSA)
• Ensure zero hardcoded secrets, strict environment isolation, and full auditability
• Leverage Datadog, metrics, logs, and traces to:
  • Identify bottlenecks
  • Validate SLOs in real time
  • Produce actionable post-test analysis

• Partner closely with backend engineers, SREs, and platform teams
• Translate performance findings into concrete engineering actions
• Influence architectural decisions with data, not opinions
• Act as a performance authority during game days and production readiness reviews

• 7+ years of experience in performance, load, or scalability engineering
• Proven experience testing distributed, cloud-native systems
• Strong hands-on experience with K6 (or Gatling/Locust with willingness to go deep in K6)
• Experience with WebSocket performance testing at scale
• Solid programming skills (JavaScript, Java, Python, or similar)
• Deep understanding of:
  • Concurrency, async processing, and event-driven systems
  • HTTP, WebSockets, messaging/streaming patterns
• Experience running tests in Kubernetes environments
• Strong skills in performance analysis and root-cause investigation
• Comfortable working in production environments with guardrails

• Experience with sports betting, gaming, financial trading, or real-time data platforms
• Prior ownership of game day / peak traffic testing
• AWS experience (EKS, IAM, SSM, CloudTrail)
• Experience with:
  • CI/CD-driven performance testing
  • Chaos or resilience testing
  • Capacity planning and traffic forecasting

Familiarity with Testkube or similar Kubernetes-native test orchestration

If you possess some of these skills but not all of them, we still encourage you to apply!

The expected salary range for this role is based on job-related knowledge, skills, and experience. This role is eligible for the Fanatics Betting and Gaming annual bonus program and an equity award.

*Salary range is listed in USD; ranges will change based on country and state of residence, which are reflected in Geographical Zones defined by Fanatics Betting and Gaming. *Salary Range: $121,600 to $172,800 (Salary range incorporates all of our Geographical Compensation Zones and is subject to change as the Zone associated with the actual Offer is confirmed). In addition to the base, bonus, and equity, full-time employees are eligible for Medical, Dental, Vision, 401K, paid time off, and other benefits like GymPass, Pet Insurance, Family Care Benefits, Free Shipt deliveries, and more. We’ll also give you $500 to set up your home office! For information about our benefits, please visit https://benefitsatfanatics.com/