Sr. Software Engineer I, Evaluation Services (Scala)

NinjaTrader; Chicago (IL); On-site; USD 96,000 - 192,000; Full time

Job summary

NinjaTrader is seeking a Sr. Software Engineer for the Evaluation Services backend. You will design, build, and maintain Scala-based systems powering auto-liquidation, risk evaluation, and trading services.

Collaborate with Trading Services, Frontend, QA, and Solutions Engineers to deliver production-ready features in a fast-paced environment. You will own features end-to-end, design data models in PostgreSQL, work with JSONB, Protobuf, and SQL repositories, and mentor junior engineers on Scala

Qualifications

• 5+ years of backend software engineering experience with real-time data and high availability.
• Strong hands-on Scala expertise and functional design patterns.
• Experience with actor-based concurrency models (Akka, Pekko, or equivalent).
• Relational DB skills with PostgreSQL and JSONB usage where appropriate.
• Experience with event-driven architectures and distributed systems.

Responsibilities

• Design and implement Scala backend services for evaluation, risk, and trading workloads.
• Build actor-based systems to handle high-throughput market data and events.
• Own features end-to-end from spec to production hand-off.
• Design data models and DB changes (PostgreSQL, JSONB) and contribute to shared schemas.
• Troubleshoot production incidents by tracing distributed flows under load.
• Maintain code quality through reviews, tests, and instrumentation.
• Collaborate with Trading Services, Solutions Engineering, and Product to translate requirements into stories.
• Contribute to architectural decisions and modernization efforts.

Skills

Scala backend

Scala

Real-time data

Distributed systems

Code reviews

Backend design

PostgreSQL

JSON/BSON

Tools

Akka

Kafka

Pub/Sub

PostgreSQL

JSONB

Protobuf

gRPC

Job description

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.

The team

NinjaTrader is a futures-focused brokerage offering low commissions, award-winning trading platforms, and a suite of customizable tools for active traders. The platform delivers integrated multi-device trading across desktop, web, and mobile, with access to thousands of third-party trading apps and add-ons.

The opportunity

Our Evaluation Services team powers funded trader programs that give aspiring traders a pathway to professional trading capital. As a Sr. Software Engineer, you will design, build, and maintain the Scala-based backend systems behind 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 Scala backend services 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 through 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 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 (ScalaTest or similar), and comfort working in a large existing Scala codebase
• Experience with actor-based concurrency models (Akka, Pekko, or equivalent), including 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 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 on code, tests, documentation, and PRs, and willingness to enforce the same standards in code review
• 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, adapts quickly when priorities shift, and can manage multiple complex backend efforts simultaneously

Nice to haves

• 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/Go transitions
• Background in observability, including distributed tracing, structured logging, and metrics (Datadog, GCP, or similar)
• Prior experience supporting enterprise or B2B partner integrations

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.

Compensation Range: $96K - $192K