Sr. Software Engineer I, Evaluation Services (Scala)

What you'll do:

We are seeking a Sr. Software Engineer to join our Evaluation Services team. Our Evaluation Services business powers funded trader programs that give aspiring traders a pathway to professional trading capital. In this role, you will design, build, and maintain the Scala-based backend systems that power our auto-liquidation engine, risk evaluation, and trading services—the core systems our platform and our partners depend on. You will own complex backend problems end-to-end and work alongside Trading Services Engineers, frontend engineers, QA, and solutions engineers to deliver high-quality, production-ready features in a fast-paced environment.

In this role you will:

• 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 (Akka or similar) that handle high-throughput market data, position changes, and event-driven workflows
• Own significant features end-to-end: from technical spec through implementation, code review, and production hand-off
• Design data models and database changes (PostgreSQL, including JSONB where appropriate), and contribute to the 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: thorough PR reviews, clear acceptance criteria, dev-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 tech-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'll need:

• 5+ years of backend software engineering experience building production systems that handle real-time data, concurrency, and high availability
• Strong, hands-on Scala expertise—idiomatic Scala, functional patterns, testing (ScalaTest or similar), and comfort working in a large existing Scala codebase
• Experience with actor-based concurrency models (Akka, Pekko, or equivalent)—understanding of supervision, message passing, and back-pressure
• Solid relational database skills with PostgreSQL—schema design, indexing, query optimization, and judgment on when JSONB is appropriate vs. when a normalized structure is correct
• Comfort with event-driven architectures, message buses (Kafka, Pub/Sub, or similar), 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 specs, scope work realistically, and flag risk early
• High-quality standards for code, tests, documentation, and PRs—and 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

Bonus Points for:

• Experience with trading platforms, fintech, or capital markets technology
• Understanding of trading concepts: 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 → Rust/Go transitions
• Background in observability: distributed tracing, structured logging, and metrics (Datadog, GCP, or similar)
• Prior experience supporting enterprise or B2B partner integrations

Compensation:

The salary range for this role will be $125,000.00 - $175,000.00 USD. In addition, this position will also receive an annual target bonus of 10%. Bonus pay at NinjaTrader is based on individual performance (50%) as well as company/team performance (50%).

Salary and bonus earnings are only two components of the total compensation package offered by NinjaTrader. NinjaTrader offers a 401K plan through ADP under which the company will match up to 3.5% of employee contributions. Annual paid time off allowance accrues at a rate of 18 days per year (some positions may qualify for more) plus seven paid holidays.

Location:

This role is based in Chicago, IL. *There may be remote flexibility for exceptional candidates in the following states: 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, Wisconsin.

Hybrid:

For Chicago-based employees, we follow a hybrid work schedule: In-office Tuesday through Thursday, with remote work on Mondays and Fridays. In addition to these weekly remote days, we offer:

• 20 additional flex remote days annually
• 5 Company Wide Office-Optional weeks tied to major holidays