Developer-Full Stack Senior

Job#: 3030863 Job Description: We are hiring Senior Full Stack Developer (Python-Focused)! Role: Senior Full Stack Developer Supporting: Large Financial Services Client Location: McLean, VA (Onsite) Assignment Type: Contract Duration: Approx. 3 Months Role Overview: We are seeking a Senior Full Stack Developer with deep Python expertise to contribute to an enterprise‑scale forecasting and financial modeling platform that supports long‑term projections and high‑visibility reporting. This role focuses on enhancing performance, scalability, and accuracy of core systems, supporting critical production cycles, and partnering with stakeholders to deliver new forecasting and scenario analysis capabilities. Ideal candidates are experienced, detail‑oriented engineers who thrive in complex, data‑driven environments. Key Responsibilities: • Refactor and modernize existing financial accounting and forecasting application components to improve maintainability, performance, and scalability • Develop and enhance core forecasting engine features to improve model accuracy, runtime efficiency, and enterprise readiness • Support critical quarterly and annual production runs by monitoring execution, troubleshooting issues, and ensuring data integrity and timely delivery • Diagnose and resolve defects, reduce technical debt, and drive continuous improvement aligned with software engineering best practices • Write clean, robust, high ‑ quality code supported by strong automated unit and integration test coverage • Collaborate across the full stack, including data, services, APIs, and infrastructure, to deliver end ‑ to ‑ end solutions • Partner with business stakeholders to implement new forecasting capabilities and support scenario analysis • Assist with infrastructure upgrades, platform migrations, and adoption of new technologies to improve reliability and operational efficiency • Contribute to design discussions, code reviews, and documentation with a collaborative, solution ‑ oriented mindset Qualifications: • 5+ years of hands ‑ on Python development experience (Java is a plus) • Experience using Git for version control in a team ‑ based development environment • Strong experience with SQL and relational databases • Hands ‑ on experience with unit testing frameworks (e.g., Pytest, JUnit) • Experience with containerization and orchestration tools (Docker, Podman, Kubernetes) • Proficiency with shell scripting for automation, troubleshooting, and operational support • Experience developing and supporting enterprise‑scale applications • Understanding of fixed income concepts such as duration, convexity, spreads, and option‑adjusted spread (OAS) • Strong critical thinking, problem‑solving skills, and familiarity with Agile development practices • Clear written and verbal communication skills Preferred: • Graduate degree in Computer Science, Mathematics, Statistics, or a related quantitative discipline • Knowledge of GAAP accounting fundamentals (e.g., revenue/expense recognition, amortization) • CFA, FRM, CPA, or meaningful progress toward certification • Experience working directly with stakeholders to gather requirements and drive delivery • Exposure to planning and tracking tools such as JIRA Compensation and Benefits: The pay rate for this position is between $55.00 and $75.57per hour. Please note that the final rate may be contingent on experience and other factors. This employer is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, or protected veteran status and will not be discriminated against on the basis of disability. Apex uses a virtual recruiter as part of the application process. Click here for more details. If you have visited our website in search of information on employment opportunities or to apply for a position, and you require an accommodation in using our website for a search or application, please contact our Benefits Department at [email protected] or 804-523-8228. Apex Systems is a world-class IT services company that serves thousands of clients across the globe. When you join Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing® in Talent Satisfaction in the United States and Great Place to Work® in the United Kingdom and Mexico. Apex uses a virtual recruiter as part of the application process. Click here for more details. Apex Benefits Overview: Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our ‘Welcome Packet’ as well, which an Apex team member can provide. Apex Systems is a world-class IT services company that serves thousands of clients across the globe. When you join Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing® in Talent Satisfaction in the United States and Great Place to Work® in the United Kingdom and Mexico. Apex uses a virtual recruiter as part of the application process. Click here for more details. Apex Benefits Overview: Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our ‘Welcome Packet’ as well, which an Apex team member can provide. Apex Systems is part of the Commercial Segment of ASGN Incorporated. NYSE: ASGN 4400 Cox Road Suite 200 Glen Allen, Virginia 23060 Apex Systems is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law. If you have visited our website in search of information on employment opportunities or to apply for a position, and you require an accommodation in using our website for a search or application, please contact our Benefits Department at [email protected] or 804-523-8228. (Do not submit resumes or solicit consultants to this email address). UnitedHealthcare creates and publishes the Transparency in Coverage Machine-Readable Files on behalf of Apex Systems.