Sr. Software Engineer II, Fullstack - NT Connect

NinjaTrader•Chicago, IL

6d•$150,000 - $200,000•Hybrid

About The Position

NinjaTrader is building NT Connect — our API-based brokerage integration layer that powers connections with introducing brokers, fintech partners, and third-party platforms. We're looking for a Sr. Fullstack Engineer to join the NT Connect team and help us design and build the services, APIs, and developer experience that make our platform a joy to integrate with. If you're passionate about crafting high-quality full-stack systems in a fintech environment where your work directly shapes partner outcomes and trading experiences, this is your opportunity. You'll work across the entire stack — backend services, API architecture, web tooling, and partner integration workflows — to create a scalable, secure, high-throughput platform. As a senior engineer on the NT Connect team, your contributions will significantly impact the developer experience, product roadmap, and overall business outcomes.

Requirements

Bachelor's or Master's degree in Computer Science, Software Engineering, or a related field (or equivalent practical experience)
8+ years of professional software development experience, with strong depth across both frontend and backend systems
Strong backend engineering skills with Node.js and TypeScript, including building production-grade APIs, authentication flows, and API versioning strategies
Proven experience designing RESTful and WebSocket APIs for external partners or B2B platforms
Strong frontend engineering skills with a modern framework (React preferred); ability to deliver complex, data-driven UIs with high attention to design fidelity
Hands-on experience with cloud-native environments: Docker, Kubernetes, and GCP
Strong SQL and database knowledge, including schema design, query optimization, and migrations
Experience with performance optimization, caching strategies, and event-driven architectures
Demonstrated use of AI coding agents (e.g., GitHub Copilot, Cursor, Claude Code) to meaningfully improve personal and team productivity — treating AI-assisted development as a standard part of the modern engineering workflow
Strong written and verbal communication skills; comfortable working with partner-facing and cross-functional teams, with the ability to take full ownership of projects from design through deployment, maintenance, and iteration

Nice To Haves

Familiarity with OAuth2, JWT, API key systems, or signed request authentication patterns
Experience with financial, brokerage, or trading systems
Experience with message queues or streaming platforms (e.g., Pub/Sub, Kafka)
Experience building SDKs or developer toolchains for external integrators
Familiarity with infrastructure-as-code tools such as Terraform
Experience working in a regulated fintech, trading, or brokerage environment

Responsibilities

Contribute to the development, optimization, and operational health of NT Connect's web-based platform, building new features and maintaining existing ones across the full stack
Design and implement scalable, efficient backend services and APIs using Node.js and TypeScript, deployed on cloud-based infrastructure (e.g., Google Cloud Platform)
Collaborate closely with UX/UI designers to translate design prototypes into high-quality, scalable frontend code that adheres to NinjaTrader's design system and branding guidelines
Ensure seamless integration of frontend components with backend systems, including account management tools, partner onboarding flows, and real-time market data feeds
Develop and maintain real-time performance monitoring and logging solutions to ensure the platform remains responsive, observable, and production-ready
Collaborate with other engineering teams, QA, and Product Managers to deliver end-to-end partner solutions that meet reliability, compliance, and usability standards
Leverage AI coding agents (e.g., GitHub Copilot, Cursor, Claude Code) and modern developer tooling to accelerate delivery, improve code quality, and raise the team's engineering velocity