Job Title: Principal Engineer Backend Company Name: Pennymac Job Url: https://careers.pennymac.com/jobs/37071?lang=en-us&mode=apply&iis=Job+Board&iisn=ZipRecruiter Job Description: Skip to Main Content CORR | TPO | PFSI | PMT | CAREERS | ABOUT US RETURNING USER LOG IN Careers - Life at PennyMac Tech Early Career Veterans & Military Locations California applicants, please view our Privacy Policy and our Privacy Notice. Back Principal Engineer Backend 37071 Westlake Village, California; Cary, North Carolina; Carrollton, Texas Technology $90,000 - $150,000 OFFICE mail_outline Get future jobs matching this search or Job Description PENNYMAC Pennymac (NYSE: PFSI) is a specialty financial services firm with a comprehensive mortgage platform and integrated business focused on the production and servicing of U.S. mortgage loans and the management of investments related to the U.S. mortgage market.    At Pennymac, our people are the foundation of our success and at the heart of our dynamic work culture. Together, we work towards a unified goal of helping millions of Americans achieve aspirations of homeownership through the complete mortgage journey. Job Overview The Opportunity As a Principal Backend Engineer on the Nexus team, you will be a core architect and builder of the platform's "brain." You won't just be building standard web APIs; you'll be engineering the complex, high-performance backend systems that power our autonomous AI agents, manage our "Unified Context Library," and orchestrate multi-step developer workflows. This role requires a unique blend of elite backend engineering, a deep understanding of developer tooling, and hands-on experience with the new stack of AI-native infrastructure. You will be working directly with your "stakeholders"—other engineers—to understand their pain points and rapidly incorporate their feedback into the tools you build. Why Join Pennymac? Chart Pennymac’s AI Course: This is a greenfield opportunity to join a foundational "internal startup" and build a transformative platform from the ground up, with the stability and resources of an industry leader. High-Impact & Visibility: This AI platform is a top-priority strategic initiative. Your work will be highly visible to senior leadership and will have a direct, measurable impact on the productivity of our entire technology organization. Solve Unique Problems: You'll be tackling cutting-edge challenges in applied AI, developer productivity, and large-scale data orchestration—problems that few companies are solving at this scale. Competitive Compensation: We offer a competitive salary, bonus, and benefits package, including comprehensive health/dental/vision plans, 401(k) matching, and more. Career Growth: We are committed to the growth of our team members and provide opportunities for continuous learning, professional development, and career advancement within a leading FinTech company. A Typical Day Architect and build the core backend systems for the AI SDLC platform in a cloud-native (AWS) environment using Node.js and TypeScript. Design, implement, and scale the "Unified Context Library," our RAG (Retrieval-Augmented Generation) foundation. This includes ingesting and vectorizing vast amounts of institutional knowledge from sources like Confluence, Jira, and Gitlab. Develop robust orchestration flows for autonomous AI agents using frameworks like the AWS Bedrock AgentCore and LangChain.ts. Build and maintain secure, scalable APIs for deep, bi-directional integrations with third-party developer tools (e.g., GitLab, Jira, ServiceNow). Engineer high-performance developer-focused services (e.g., Language Server Protocol-style backends) that can interact with code repositories, run linters, parse test results, and provide real-time feedback to AI agents. Collaborate in a highly agile, "internal startup" environment, working directly with product managers and fellow engineers to define, build, and rapidly iterate on new features based on user feedback. Take full ownership of the services you build, from architectural design and implementation to DevOps (IaC), testing, and production operations. Recommend and evaluate new technologies, architectures, and processes to ensure our AI platform is scalable, resilient, and cutting-edge. What You’ll Bring Architect and build the core backend systems for the AI SDLC platform in a cloud-native (AWS) environment using Node.js and TypeScript. Design, implement, and scale the "Unified Context Library," our RAG (Retrieval-Augmented Generation) foundation. This includes ingesting and vectorizing vast amounts of institutional knowledge from sources like Confluence, Jira, and Gitlab. Develop robust orchestration flows for autonomous AI agents using frameworks like the AWS Bedrock AgentCore and LangChain.ts. Build and maintain secure, scalable APIs for deep, bi-directional integrations with third-party developer tools (e.g., GitLab, Jira, ServiceNow). Engineer high-performance developer-focused services (e.g., Language Server Protocol-style backends) that can interact with code repositories, run linters, parse test results, and provide real-time feedback to AI agents. Collaborate in a highly agile, "internal startup" environment, working directly with product managers and fellow engineers to define, build, and rapidly iterate on new features based on user feedback. Take full ownership of the services you build, from architectural design and implementation to DevOps (IaC), testing, and production operations. Recommend and evaluate new technologies, architectures, and processes to ensure our AI platform is scalable, resilient, and cutting-edge. Why You Should Join As one of the top mortgage lenders in the country, Pennymac has helped over 4 million lifetime homeowners achieve and sustain their aspirations of home. Our vision is to be the most trusted partner for home. Together, 4,000 Pennymac team members across the country are guided by our core values: to be Accountable, Reliable and Ethical in all that we do. Pennymac is committed to conducting a business that makes positive contributions and promotes long-term sustainable growth and to fostering an equitable and inclusive environment, where all employees and customers feel valued, respected and supported.    Benefits That Bring It Home: Whether you're looking for flexible benefits for today, setting up short-term goals for tomorrow, or planning for long-term success and retirement, Pennymac's benefits have you covered. Some key benefits include:  Comprehensive Medical, Dental, and Vision Paid Time Off Programs including vacation, holidays, illness, and parental leave  Wellness Programs, Employee Recognition Programs, and onsite gyms and cafe style dining (select locations) Retirement benefits, life insurance, 401k match, and tuition reimbursement  Philanthropy Programs including matching gifts, volunteer grants, charitable grants and corporate sponsorships   To learn more about our benefits visit: https://pennymacnews.page.link/benefits   For residents with state required benefit information, additional information can be found at: https://www.pennymac.com/additional-benefits-information   Compensation: Individual salary may vary based on multiple factors including specific role, geographic location / market data, and skills and experience as defined below: Lower in range - Building skills and experience in the role Mid-range - Experience and skills align with proficiency in the role  Higher in range - Experience and skills add value above typical requirements of the role    Some roles may be eligible for performance-based compensation and/or stock-based incentives awarded to employees based on company and individual performance.    Salary $90,000 - $150,000 Work Model OFFICE Apply Share This Job Pennymac is an equal opportunity employer. Pennymac values diversity and is committed to creating an inclusive environment for all employees. Pursuant to Pennymac’s Equal Employment Opportunity (EEO) policy, all qualified applicants will be considered without regard to any protected characteristic under state, federal, or local law, including, but not limited to race, color, creed, religion (including religious dress and grooming practices), age, sex (including pregnancy, childbirth, breastfeeding or related medical conditions), gender (including gender identity and gender expression), national origin (including language use or possession of a driver’s license issued under Vehicle Code § 12801.9), citizenship, ancestry, physical or mental disability, medical condition, genetic information, marital status, registered domestic partner status, sexual orientation, status as a victim of domestic violence, assault or stalking, military or veteran status, and/or political affiliation or activity. We encourage applications from all qualified candidates and will reasonably accommodate applicants’ needs in accordance with applicable law throughout all stages of the recruitment and selection process. If you need a reasonable accommodation to assist with your job search or application for employment, please contact us by sending an email to employeerelations@pennymac.com In your email please describe specific accommodation you are requesting and the position for which you are applying. Information received relating to accommodation will be addressed confidentially. USCIS facilitates compliance with U.S. immigration law by providing E-Verify program support, user support, training and outreach, and developing innovative technological solutions in employment eligibility verification. Review requirements by clicking on the IER Right to Work link link and the E-Verify Participation Poster link link. Equal Housing Opportunity © 2024 PennyMac Loan Services, LLC, 3043 Townsgate Rd, Suite 200, Westlake Village, CA 91361, 818-224-7442. NMLS ID # 35953. For licensing information, go to: www.nmlsconsumeraccess.org. Legal Privacy Policy Terms of Use Fees Do Not Sell or Share My Personal Information Notice at Collection for CA Residents Site Accessibility Arizona Mortgage Banker License # 0911088. Licensed by the Department of Financial Protection and Innovation under the California Residential Mortgage Lending Act. Colorado office: 5500 South Quebec Street, Suite 260 Greenwood Village, CO 80111, (877) 215-2552. Massachusetts Mortgage Lender License # MC35953. Minnesota: This is not an offer to enter into an agreement and an offer may only be made pursuant to Minn. Stat. §47.206 (3) & (4). Licensed by the N.J. Department of Banking and Insurance. Licensed Mortgage Banker-NYS Department of Financial Services. North Carolina Permit No. 119504607, 119505929, 119506567, 119506570, 119507419. Rhode Island Licensed Lender # 20092600LL, Loan Broker, and Third Party Loan Servicer. Texas office: 2201 W. Plano Parkway, Suites 150 and 300, Plano, TX 75075. For more information, review Pennymac’s state licenses and important notices. Not all property types qualify. Some loan products may not be available in all states. Information, property type eligibility, rates and pricing are subject to change without prior notice at the sole discretion of PennyMac Loan Services, LLC. Ask your loan officer for details. All loan programs subject to borrowers meeting appropriate underwriting conditions. This is not a commitment to lend. Other restrictions apply. The information included in this communication is considered confidential and proprietary, and any unauthorized reproduction is prohibited. © 2025 Private National Mortgage Acceptance Company, LLC, Pennymac and all related marks are trademarks of Private National Mortgage Acceptance Company, LLC and/or its subsidiaries or affiliates. Use of Olympic footage authorized by the IOC and by the USOPC (36 U.S.C. § 220506). The use of Olympic Marks, Terminology and Imagery is authorized by the U.S. Olympic & Paralympic Committee and LA28 pursuant to Title 36 U.S. Code Section 220506. All third-party content is the property of its respective owners. All rights reserved. (12-2025) This website may include combined information from PennyMac Financial Services, Inc. (“PFSI”) and PennyMac Mortgage Investment Trust (“PMT”) collectively Pennymac.