# Senior C# and Python Developer We are seeking a highly skilled and experienced Senior C# and Python Developer to join our team. The ideal candidate will be responsible for developing new .NET client libraries for our data platform, maintaining existing .NET and Python libraries, and supporting our desktop data browser and Excel DNA add-ins. This role requires a proactive individual who can provide L3 support, troubleshoot production issues, and contribute to lower environment support on a rotational basis. **Responsibilities:** - Design, develop, and implement new .NET client libraries using **.NET Core** for seamless integration with our data platform, with a strong focus on **Multithreading** and **LINQ**. - Maintain and enhance existing .NET libraries, ensuring high performance, reliability, and scalability. - Develop and maintain Python libraries for data platform interactions. - Support and improve the desktop data browser application, ensuring a robust user experience. - Develop and maintain Excel DNA add-ins to extend data platform functionality within Excel. - Provide L3 support for production issues, including root cause analysis and timely resolution. - Perform troubleshooting for issues across various environments (development, UAT, production). - Participate in a rotational schedule for lower environment support, ensuring smooth operations and stability. - Collaborate with cross-functional teams to understand requirements and deliver high-quality solutions. - Write comprehensive technical documentation for all developed components and systems. - Participate in code reviews to ensure code quality, adherence to best practices, and knowledge sharing. **Required Skills and Qualifications:** - **Experience:** 6+ years of professional software development experience. - **C#/.NET:** Strong proficiency in C# and **.NET Core**, with extensive experience in **Multithreading** and **LINQ** for developing client libraries and desktop applications. Familiarity with .NET Framework for existing libraries is a plus. - **gRPC:** Hands-on experience with gRPC for building high-performance, language-agnostic service communication. - **WPF and WinForms:** Hands-on experience with Windows Presentation Foundation (WPF) and Windows Forms (WinForms) for building desktop applications. - **Python:** Expert-level knowledge of Python, including experience with library development and data manipulation. - **Unit Testing:** Strong understanding and experience with unit testing frameworks and practices for C# and Python. - **Security:** Strong understanding of secure coding practices and a good sense of security in software development. - **Excel DNA:** Proven experience in developing and maintaining Excel DNA add-ins. - **Troubleshooting & Support:** Excellent problem-solving skills with a strong ability to provide L3 support and troubleshoot complex production issues. - **Communication:** Strong verbal and written communication skills, with the ability to articulate technical concepts clearly. - **Teamwork:** Ability to work effectively in a collaborative team environment. - **Proactive:** Self-motivated and proactive in identifying and resolving issues. **Preferred Qualifications:** - Experience with data platforms and related technologies. - Familiarity with CI/CD pipelines and DevOps practices. - Experience in financial services or a related regulated industry. - Knowledge of various testing methodologies and tools. ------------------------------------------------------ ## **Job Family Group:** Technology ------------------------------------------------------ ## **Job Family:** Applications Development ------------------------------------------------------ ## **Time Type:** Full time ------------------------------------------------------ ## **Most Relevant Skills** Please see the requirements listed above. ------------------------------------------------------ ## **Other Relevant Skills** For complementary skills, please see above and/or contact the recruiter. ------------------------------------------------------ *Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law.* *If you are a person with a disability and need a reasonable accommodation to use our search tools and/or apply for a career opportunity review* *[Accessibility at Citi](https://www.citigroup.com/citi/accessibility/application-accessibility.htm).* *View Citi’s [EEO Policy Statement](https://www.citigroup.com/global/eeo-aa-policy) and the [Know Your Rights](https://www.eeoc.gov/sites/default/files/2023-06/22-088_EEOC_KnowYourRights6.12ScreenRdr.pdf) poster.*