Sr. Software Engineer I, Scala

NinjaTrader; Chicago (IL); On-site; USD 125,000 - 175,000; Full time

Job summary

NinjaTrader, a leading futures trading platform, is seeking a Sr. Software Engineer to join our Evaluation Services team in Chicago.

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 partners rely on. You will own significant features end-to-end, mentor juniors, and collaborate with Trading Services, Solutions Engineering, and Product to translate business

Qualifications

• 5+ years of backend production systems experience.
• Strong Scala expertise with idiomatic patterns and testing (ScalaTest or similar).
• Experience with actor-based concurrency models (Akka, Pekko).
• Relational database skills with PostgreSQL, including JSONB usage.
• Familiarity with event-driven architectures and Kafka or Pub/Sub.
• Excellent troubleshooting skills across distributed systems and logs.
• Ability to write clear technical specifications, scope work realistically, and identify risks early.
• Commitment to high standards for code, tests, and documentation; strong code reviews.
• Strong communication skills to explain backend tradeoffs to technical and non-technical audiences.
• Self-starter who thrives in ambiguity and can handle multiple backend initiatives.

Responsibilities

• Design and implement backend services in Scala for evaluation and trading workloads.
• Build actor-based systems to handle high-throughput market data and event-driven workflows.
• Own features end-to-end from specs to production handoff.
• Design data models in PostgreSQL, including JSONB where appropriate.
• Diagnose and resolve complex backend incidents under pressure.
• Maintain code quality with thorough PR reviews and testing practices.
• Collaborate with cross-functional teams to translate business requirements into stories.
• Contribute to architectural decisions and modernize legacy Scala services.
• Mentor junior engineers on Scala idioms and testing practices.
• Develop deep expertise in NinjaTrader's evaluation platform and integrations.

Skills

Scala

Akka

PostgreSQL

Kafka

Pub/Sub

JSONB

Distributed systems

Troubleshooting

Code reviews

Technical specs

Communication

Mentoring

Tools

Protobuf

gRPC

Datadog

Job description

Disclaimer: Please be advised that the most accurate and up-to-date information about our open roles—including job descriptions, compensation, and benefits—can only be guaranteed on our official job board. For the latest listings and details, please visit: https://job-boards.greenhouse.io/ninjatrader.

JOIN US ON OUR MISSION TO BECOME THE #1 RETAIL TRADING PLATFORM IN THE WORLD

Welcome to the dynamic world of NinjaTrader! As an industry-leading trading platform and futures broker, we’re empowering traders to take control of their financial destiny. How do we do it? We provide cutting-edge products and services that enhance the trading journey. Whether a seasoned pro or just starting out, NinjaTrader equips traders with award-winning software and brokerage services to navigate the world’s leading financial markets with confidence. Our growth story is nothing short of exhilarating. Since 2003, NinjaTrader has been dedicated to understanding and supporting traders on their journey toward trading triumph. Through those efforts, our user base has grown to over 2 million users and we have become the number one rated futures brokerage worldwide. But we’re not stopping there. We’re constantly evolving, pushing boundaries, and modernizing the futures industry. Our commitment to innovation means users will always have access to dynamic tools, real-time support, and a community of like-minded traders. So, why work at NinjaTrader? Here, you’re not just part of a team; you’re part of a movement. We empower employees to reach new heights in their careers by providing a dynamic culture focused on social connection, professional development, and employee recognition initiatives. Sounds too good to be true? Take it from our employees. Join us as we redefine what’s possible in trading, advocate for our customers, and continue our journey toward becoming the world’s top retail-focused trading platform in the world.

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. 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 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 service workloads, including real-time auto-liquidation, account state management, and post-trade processing
• Build and evolve actor-based systems, such as Akka or similar technologies, that handle high-throughput market data, position changes, and event-driven workflows
• Own significant features end-to-end, from technical specifications through implementation, code review, and production handoff
• Design data models and database changes in 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 loads
• Drive code quality across the team through thorough pull request reviews, clear acceptance criteria, disciplined development testing, and proper instrumentation and observability
• Collaborate with Trading Services, Solutions Engineering, and Product to translate business requirements into well-scoped, accurately estimated stories
• Contribute to architectural decisions and long-term technical debt remediation, including modernizing legacy Scala services and evaluating 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, including idiomatic Scala, functional patterns, testing with ScalaTest or similar tools, and comfort working in a large, existing Scala codebase
• Experience with actor-based concurrency models, such as Akka, Pekko, or equivalent technologies, including an understanding of supervision, message passing, and backpressure
• Solid relational database skills with PostgreSQL, including schema design, indexing, query optimization, and sound judgment about when to use JSONB versus a normalized structure
• Comfort with event-driven architectures, message buses such as Kafka or Pub/Sub, and asynchronous workflows
• Excellent troubleshooting skills, with the ability to read logs, trace requests across distributed systems, and isolate root causes under pressure
• Demonstrated ability to write clear technical specifications, scope work realistically, and identify risks early
• High standards for code, tests, documentation, and pull requests, along with a willingness to uphold those standards during code reviews
• 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 explain backend tradeoffs to technical and non-technical audiences
• Self-starter who thrives in ambiguity and can manage multiple complex backend initiatives simultaneously

Bonus points for:

• Experience with trading platforms, fintech, or capital markets technology
• Understanding of trading concepts, including order routing, market data, position management, risk and liquidation logic, and profit and loss calculations
• Familiarity with Protobuf, gRPC, or schema-based service contracts
• Experience migrating or modernizing legacy Scala systems or evaluating transitions from Scala to Rust or Go
• Background in observability, including distributed tracing, structured logging, and metrics using Datadog, Google Cloud Platform, or similar technologies
• Prior experience supporting enterprise or business-to-business 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 12%. 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

Our Core Benefits Include:

• Generous PTO
• 7 Paid Holidays Annually + 5 Conditional Holidays Annually
• 1 Service Day Annually
• 401k with 3.5% Company Match
• Paid Parental Bonding Leave
• Health, Vision, Dental Coverage
• Life and Disability Insurance Covered 100% by NinjaTrader

We are committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender, gender identity or expression, or veteran status. We are proud to be an equal opportunity workplace.