Sr. Software Engineer I, Evaluation Services (Scala)

As a Sr. Software Engineer on the Evaluation Services team at NinjaTrader, you will design, build, and maintain the Scala-based backend systems that power funded trader programs. You own complex backend problems end-to-end, working with Trading Services Engineers, frontend engineers, QA, and solutions engineers to deliver high-quality, production-ready features that handle real-time auto-liquidation, risk evaluation, and trading services workloads.

What you'll do

• Design and implement backend services in Scala for evaluation, risk, and trading services workloads, including real-time auto-liquidation, account state management, and post-trade processing
• Build and evolve actor-based systems using Akka or similar frameworks to handle high-throughput market data, position changes, and event-driven workflows
• Own significant features end-to-end, from technical specification through implementation, code review, and production deployment
• Design data models and database changes using PostgreSQL (including JSONB where appropriate), and contribute to shared master schema, Protobuf, and SQL repositories
• Diagnose and resolve complex backend issues, including production incidents, by analyzing logs, tracing distributed flows, and reproducing edge cases under realistic load
• Drive code quality across the team through thorough code reviews, clear acceptance criteria, development testing discipline, and proper instrumentation and observability
• Collaborate with Trading Services, Solutions Engineering, and Product to translate business requirements into well-scoped, well-estimated stories
• Contribute to architectural decisions and long-term technical debt remediation, including modernization of legacy Scala services and evaluation of new event-bus technologies
• Mentor junior team members on Scala idioms, functional design, testing practices, and incident response
• Develop deep expertise in NinjaTrader's evaluation platform and partner integrations to provide authoritative backend leadership

What you bring

• 5+ years of backend software engineering experience building production systems that handle real-time data, concurrency, and high availability
• Strong, hands-on Scala expertise including idiomatic Scala, functional patterns, testing frameworks like ScalaTest, and comfort working in large existing Scala codebases
• Experience with actor-based concurrency models such as Akka or Pekko, including understanding of supervision, message passing, and back-pressure
• Solid relational database skills with PostgreSQL, including schema design, indexing, query optimization, and judgment on when JSONB is appropriate versus normalized structures
• Comfort with event-driven architectures, message buses like Kafka or Pub/Sub, and asynchronous workflows
• Excellent troubleshooting skills with the ability to read logs, trace requests across distributed systems, and isolate root cause under pressure
• Demonstrated ability to write clear technical specifications, scope work realistically, and flag risk early
• High-quality standards for code, tests, documentation, and pull requests, with willingness to enforce the same standards in code review
• Ability to think on your feet and adapt quickly when priorities shift or unexpected issues arise
• Outstanding written and verbal communication skills with the ability to translate backend tradeoffs for both technical and non-technical audiences
• Self-starter who thrives in ambiguity and can manage multiple complex backend efforts simultaneously

Nice to have

• Experience with trading platforms, fintech, or capital markets technology
• Understanding of trading concepts such as order routing, market data, position management, risk and liquidation logic, and P&L calculation
• Familiarity with Protobuf, gRPC, or schema-based service contracts
• Experience migrating or modernizing legacy Scala systems or evaluating Scala to Rust or Go transitions
• Background in observability including distributed tracing, structured logging, and metrics platforms such as Datadog or GCP
• Prior experience supporting enterprise or B2B partner integrations

What we offer

• Salary of $125,000 to $175,000 USD annually, plus an annual target bonus of 10% based on individual performance (50%) and company/team performance (50%)
• 401(k) plan with 3.5% company match
• 18 days of paid time off annually, plus 7 paid holidays and 5 conditional holidays
• 1 service day annually
• Health, vision, and dental coverage
• Life and disability insurance covered 100% by NinjaTrader
• Paid parental bonding leave
• Hybrid work schedule for Chicago-based employees: in-office Tuesday through Thursday, remote Monday and Friday, plus 20 additional flex remote days annually and 5 company-wide office-optional weeks tied to major holidays
• Remote flexibility for exceptional candidates in California, Colorado, Florida, Georgia, Illinois, Indiana, Minnesota, Missouri, Montana, New Jersey, New York, North Carolina, Ohio, Oregon, Pennsylvania, South Carolina, Texas, Utah, Vermont, Virginia, Washington, Washington DC, and Wisconsin

About NinjaTrader

NinjaTrader is an industry-leading trading platform and futures broker with over 2 million users, providing award-winning software and brokerage services. The company is the number one rated futures brokerage worldwide and is dedicated to modernizing the futures industry through cutting-edge products, real-time support, and community for traders.