Principal Engineer Backend

Apply for the Principal Engineer Backend role at PENNYMAC
.

Pennymac (NYSE: PFSI) is a specialty financial services firm focused on the production and servicing of U.S. mortgage loans and the management of investments related to the U.S. mortgage market. As a trusted partner, Pennymac has helped over 4 million homeowners achieve and sustain their home ownership aspirations.

As a Principal Backend Engineer on the Nexus team, you will be a core architect and builder of the platform’s “brain,” engineering complex, high‑performance backend systems that power autonomous AI agents, manage the “Unified Context Library,” and orchestrate multi‑step developer workflows in a cloud‑native (AWS) environment using Node.js and Type Script.

• Architect and build core backend systems for the AI SDLC platform.
• Design, implement, and scale the “Unified Context Library” (a RAG foundation) ingesting knowledge from Confluence, Jira, Git Lab.
• Develop robust orchestration flows for autonomous AI agents using AWS Bedrock Agent Core and Lang Chain.ts.
• Build and maintain secure, scalable APIs for bi‑directional integrations with third‑party developer tools (Git Lab, Jira, Service Now).
• Engineer high‑performance developer‑focused services (e.g., Language Server Protocol‑style backends) that 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 with product managers and fellow engineers to define, build, and rapidly iterate on new features.
• Own the services end‑to‑end—from architectural design and implementation to Dev Ops (IaC), testing, and production operations.
• Recommend and evaluate new technologies, architectures, and processes to ensure the platform remains scalable, resilient, and cutting‑edge.

• Extensive experience with Node.js, Type Script, and AWS cloud services.
• Strong background in building high‑performance, scalable backend systems.
• Proficiency with integrations to tools such as Git Lab, Jira, Service Now.
• Experience with AI/ML infrastructure, particularly RAG, autonomous agents, and Lang Chain.
• Hands‑on Dev Ops skills:
  IaC, CI/CD pipelines, cloud monitoring.
• Excellent communication and collaboration skills; ability to solicit and incorporate stakeholder feedback.

• Comprehensive Medical, Dental, and Vision coverage.
• Paid Time Off, including vacation, holidays, illness, and parental leave.
• Wellness programs, employee recognition, and on‑site gyms (select locations).
• Retirement benefits: 401(k) matching, life insurance, tuition reimbursement, philanthropy programs.

• Base salary range: $90,000 – $150,000, varying by role, location, and experience.
• Eligibility for performance‑based compensation and stock‑based incentives.

Office

Not Applicable

Full‑time

Engineering and Information Technology