Senior Software Engineer

Financial Services Company; New York (NY); Hybrid; USD 120,000 - 180,000; Full time

Job summary

The Financial Services Company is seeking a Backend Engineer to design scalable, high-performance backend systems in a capital markets setting. You will drive technical direction and collaborate across teams to deliver reliable services using C#/.NET or Java.

Requirements include distributed messaging, NoSQL (MongoDB), FIX protocol, and identity/authentication frameworks. You will work with observability tools like Datadog/Elasticsearch and contribute to frontend work with React where applicable.

Qualifications

• 5+ years of software development with backend focus.
• Strong proficiency in C#/.NET backend development.
• Experience designing and building APIs.
• Experience with distributed messaging/event-driven architectures.
• Hands-on FIX protocol experience.
• Experience with identity/authentication frameworks (OAuth2/OpenID).
• Experience with financial calculations, pricing engines, or quantitative models.
• Hands-on experience with MongoDB.
• Familiarity with telemetry/observability tools (Sentry/Datadog/Elasticsearch).
• Strong cross-functional collaboration.

Responsibilities

• Design and develop backend services in C#/.NET or Java.
• Build ASP.NET service-side applications for scalability.
• Work with distributed messaging to support high-throughput trading.
• Develop data solutions with MongoDB.
• Design pricing models and quantitative algorithms.
• Implement FIX protocol integrations.
• Design identity/auth across backend services.
• Integrate observability via Datadog/Elasticsearch.
• Ensure numerical precision in financial calculations.
• Collaborate with product and DevOps on deployment.
• Mentor engineers and promote best practices.
• Contribute to frontend using React (nice to have).

Skills

Backend engineering

C#/.NET

APIs design

Distributed messaging

NoSQL (MongoDB)

FIX protocol

OAuth2/OpenID IdentityServer

Observability tools

React (nice to have)

Cross-functional collaboration

Tools

ASP.NET

FIX protocol

MongoDB

Sentry

Datadog

Elasticsearch

SignalR/WebSocket

Pulsar/Databricks/Lakehouse

Job description

Delray Beach, Chicago, New York, or Charlotte preferred for in-office work; remote may be considered.

JOB SUMMARY

The Backend Engineer is responsible for designing and delivering scalable, high-performance backend systems and services within a capital markets environment. This role drives technical direction, champions engineering best practices, and collaborates across teams to build reliable, maintainable, and modern software. The ideal candidate brings deep expertise in C#/.NET (Java acceptable), hands-on experience with distributed messaging systems and NoSQL databases, and a strong foundation in ASP.NET service development. Experience with the FIX protocol and identity, authentication, and authorization systems is strongly preferred.

ESSENTIAL DUTIES AND RESPONSIBILITIES

• Design and develop high-quality backend services using C#/.NET or Java.
• Build and maintain ASP.NET service-side applications with a focus on scalability and long-term reliability.
• Work with distributed messaging frameworks and event-driven architectures to support high-throughput trading systems.
• Develop and optimize data solutions using NoSQL databases such as MongoDB.
• Design and implement financial calculation engines, pricing models, and quantitative algorithms with a strong emphasis on accuracy and performance.
• Implement and maintain FIX protocol integrations to support electronic trading workflows.
• Design and enforce identity, authentication, and authorization solutions across backend services.
• Integrate and work with observability platforms such as Datadog or Elasticsearch to support system monitoring and diagnostics.
• Ensure numerical precision in financial computations, including proper handling of rounding, accruals, and market conventions.
• Collaborate with product, UI/UX, frontend, and DevOps teams to align on development and deployment strategy.
• Build reusable, testable backend infrastructure and uphold consistent coding standards across teams.
• Implement telemetry and monitoring best practices using Sentry or equivalent tools.
• Evaluate and adopt new technologies, frameworks, and design patterns to continuously improve engineering outcomes.
• Mentor engineers on backend development best practices and foster a culture of engineering excellence.
• Contribute to frontend solutions using React and Redux/Rematch where needed. (nice to have)

REQUIRED SKILLS & EXPERIENCE

• 5+ years of software development experience with a strong emphasis on backend engineering.
• Strong proficiency in C#/.NET backend development.
• Proven experience designing and building APIs.
• Solid background in distributed messaging systems and event-driven architectures.
• Hands-on experience with the FIX protocol in a capital markets or electronic trading environment.
• Experience implementing identity, authentication, and authorization frameworks (e.g., OAuth2, OpenID Connect, IdentityServer).
• Experience implementing financial calculations, pricing engines, or quantitative models in a capital markets or fintech environment.
• Hands-on experience with QuantLib or similar quantitative finance libraries.
• Experience with NoSQL databases such as MongoDB.
• Familiarity with telemetry and observability tools such as Sentry, Datadog, or Elasticsearch.
• Experience building and scaling component libraries or design systems.
• Familiarity with fixed income or securities pricing concepts. (nice to have)
• Familiarity with Pulsar, Databricks, or Lakehouse architectures. (nice to have)
• Hands-on experience with SignalR or WebSocket-based systems. (nice to have)
• Strong communication skills and a proven track record of cross-functional collaboration.