Senior Software Engineer

Fanatics

2h

About The Position

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.

Requirements

• 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

Nice To Haves

• 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

Responsibilities

• 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

Benefits

• This role is eligible for the Fanatics Betting and Gaming annual bonus program and an equity award.
• 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!

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: No Education Listed