Sr. Software Engineer II, Platform/API

What you'll do:

NinjaTrader is investing in the platform that takes a prospective trader from initial sign-up to funded and trading, on a modern Node.js and TypeScript service architecture. We're hiring a Sr. Software Engineer II to own the service layer it runs on.

You'll own how those services are designed, deployed, and operated: event-driven orchestration, background processing, third-party integrations, and the reliability engineering that keeps a multi-step flow dependable at scale. As a senior engineer on the Activation & Onboarding squad, your work will significantly impact account approvals, time-to-funding, and how quickly we can open the platform to new markets.

In this role you will:

• Design, develop, and maintain Node.js and TypeScript services that orchestrate account creation, identity verification, agreement handling, and funding hand-off
• Build the event-driven and asynchronous processing that moves applicant and verification data between internal systems and outside providers, using message queues, pub/sub, and streaming pipelines
• Own correctness in long-running, multi-step flows: idempotency, retry and resumption semantics, deduplication, and reconciliation for steps that cannot simply be replayed
• Design and evolve the background task runners and job orchestration that drive downstream account creation and decisioning
• Build the operational tooling the squad needs when an application stalls mid-flow: inspection of in-flight state, targeted replay, and safe requeue
• Define service-level expectations for the flows you own, along with the monitoring and alerting that surface provider failures and applicant drop-off before a customer reports them
• Design and implement scalable, resilient service architecture, using cloud-based infrastructure such as Google Cloud Platform and Kubernetes
• Extend onboarding to new markets, brands, and account types, keeping jurisdiction-specific behavior configurable rather than forked
• Coordinate technical direction with engineers on adjacent squads whose systems consume your events, and coach engineers at the Sr. Software Engineer I level through design review and pairing

What you'll need:

• 6+ years of professional software development experience building and operating backend services in production
• Bachelor's or Master's degree in Computer Science, Software Engineering, or a related field (or equivalent practical experience)
• Deep Node.js and TypeScript expertise, with strong command of asynchronous patterns, concurrency, and backpressure
• Proven production experience with event-driven architecture, including delivery guarantees and poison-message handling, on message queues, pub/sub, or streaming platforms such as Kafka or Google Cloud Pub/Sub
• Demonstrated experience building idempotent, resumable workflows that stay correct under retries, partial failure, and out-of-order delivery
• Strong SQL and schema design, plus hands-on experience with Docker, Kubernetes, and a major cloud platform
• Demonstrated use of AI coding agents (Codex, Cursor, Claude Code) as a standard part of your engineering workflow, with the judgment to review and validate AI-assisted code before it ships
• Excellent communication and the ownership to run a workstream end to end: design, implement, test, deploy, operate on-call, and iterate

Bonus Points for:

• Experience with identity verification, KYC/AML, or fraud and risk decisioning systems
• Experience in fintech, trading, or brokerage, particularly in a regulated financial services environment
• Experience integrating third-party providers whose contracts and failure modes you do not control
• Familiarity with workflow or saga orchestration frameworks, and with feature flagging platforms such as Statsig
• Passion for futures, derivatives, and trading technologies is a strong plus
• This is one of two backend openings on the Activation & Onboarding squad. If both look like a fit, apply to whichever is closer to your strengths. We review candidates for both together.

Compensation:

The salary range for this role will be $140,000.00 - $190,000.00 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