.Net Web API Developer

Who We Are

Oppenheimer & Co. Inc. ("Oppenheimer") is a leading middle‑market investment bank and full service broker‑dealer. With roots tracing back to 1881, the Company is engaged in a broad range of activities in the financial services industry, including retail securities brokerage, institutional sales and trading, investment banking (both corporate and public finance), equity & fixed income research, market making, trust services and investment advisory and asset management services.

Oppenheimer & Co. Inc. is seeking a .NET Web API Developer to join our Information Technology team in our New York office. This individual will be responsible for designing, developing, testing, and maintaining server‑side logic and APIs for our suite of financial applications. This role involves collaborating closely with front‑end developers, database administrators, and business analysts to translate business requirements into efficient, secure, and reliable software solutions.

This individual will work on enhancing existing systems, developing new features, and ensuring seamless integration between various platforms. Expertise in managing and interacting with Sybase, SQL Server, and Mongo

DB databases is crucial for this position.

• Design, develop, and maintain high‑performance and scalable .NET Web APIs using C# and the .NET Framework/.NET Core
• Collaborate with cross‑functional teams to define, design, and ship new features for financial applications
• Develop robust data access layers and integrate APIs with multiple database systems, including Sybase, SQL Server, and MongoDB
• Write clean, maintainable, and efficient code following best practices and established coding standards
• Implement unit testing, integration testing, and performance testing to ensure code quality and application stability
• Troubleshoot, debug, and resolve software defects and production issues in a timely manner
• Participate in code reviews to maintain code quality, share knowledge, and ensure compliance with project standards
• Manage API versioning, documentation (e.g., using Swagger/OpenAPI), and deployment processes
• Stay up-to-date with emerging technologies and industry trends to continuously improve development practices and application performance
• Apply specific knowledge of financial systems and business processes to improve application functionality and reliability, preferred

• Minimum of 5+ years of professional experience in .NET web development, specifically with .NET Web API, C#, and the .NET Framework/.NET Core
• Proven experience working with and managing data in Sybase databases (Sybase ASE/IQ), preferred
• Extensive experience with SQL Server database design, T‑SQL programming, and performance tuning
• Hands‑on experience with MongoDB (or other No
  
  SQL databases), including data modeling and query optimization
• Experience with front‑end technologies (e.g., JavaScript, Angular/React) is a plu

• Proficiency in building RESTful APIs and microservices architecture
• Strong understanding of object‑oriented programming (OOP) principles and design patterns
• Experience with version control systems, preferably Git and Azure Dev Ops Server

• Strong analytical and problem‑solving skills
• Excellent communication and collaboration abilities
• Ability to work independently and as part of a team in a fast‑paced environment
• Detail‑oriented and committed to producing high‑quality work

• Prior experience in the finance industry or working on financial software applications

For job postings in New York City, Oppenheimer is required by law to include a reasonable estimate of the salary range for this role. This salary range is specific to the City of New York and takes into account the wide range of factors that are considered in making salary decisions including but not limited to your skills, qualifications, experience, licensure and certifications, and other business and organizational needs.

A reasonable estimate of the current base salary range is $ - $ at the time of this posting. Also, certain positions are eligible for additional forms of compensation such as discretionary bonus.