Senior Software Engineer, Sportsbook Platform

The role

You will design, scale, and tune APIs and real-time delivery services. You will build and operate services for high throughput and develop native Android and iOS features when needed. You will use AI coding agents as your main way of building.

What you will do

• Design, scale, and tune APIs and the real-time delivery behind them.
• Treat the API schema as a versioned contract with released mobile apps.
• Build and operate services that stay fast and correct under high throughput, bursty load.
• Find bottlenecks and risks in production and drive the changes that make the platform scale.
• Set up and refine monitoring, alerting, and tracing in Datadog.
• Develop native Android and iOS features in Swift or Kotlin when a feature needs it.
• Write thorough tests for every feature and bug fix.
• Own features end to end, from the API to the screen.
• Debug problems that cross the client and server boundary.
• Use AI coding agents, such as Claude Code, as your main way of building.

Required qualifications

• Hands-on, daily experience building software with AI coding agents (Claude Code, Cursor, Copilot agents, or similar).
• At least 5 years of experience in software engineering, with most of it on backend or API systems.
• 2+ years designing and evolving APIs used by multiple clients (iOS, Android, web), including versioning and backward compatibility.
• Willing to learn native iOS and Android development in Swift or Kotlin.
• Experience building real-time features, such as subscriptions, streaming, or push-based updates.
• A solid foundation in computer science, with strong competencies in data structures, distributed systems, algorithms, and software design.
• Experience finding and fixing production performance regressions, including CPU, I/O, memory, and latency problems, through load testing and tracing.
• Experience on an on-call rotation for a production service, and owning release cycles end to end.
• Experience with a server framework such as Phoenix, Ruby on Rails, FastAPI, Laravel, or Node.
• Clear writing.
• Comfortable working in the terminal, with Git and GitHub or similar, and in an editor of your choice.

Nice to have

• Native mobile experience in Swift or Kotlin.
• GraphQL, including federated graphs
• Elixir and Absinthe
• Strong relational database skills, such as PostgreSQL or MySQL
• Kubernetes and operating services in containers
• Background job processing (Oban, Exq, Sidekiq, Celery) and event infrastructure (Kafka, RabbitMQ, SQS/SNS, Pub/Sub)

Benefits

• Competitive compensation package
• Fun, relaxed work environment
• Education and conference reimbursements.
• Opportunities for career progression and mentoring others

About the company

PENN Entertainment, Inc. is North America’s leading provider of integrated entertainment, sports content, and casino gaming experiences. They deliver experiences through casinos, racetracks, online gaming, sports betting and entertainment content.