Frontend Engineer - AI Platform

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 home ownership through the complete mortgage journey.

As a Frontend Engineer on the AI Platform Services team, you will be a core builder of the platform's "face" and a champion for the user experience. While the backend team builds the "brain" (RAG pipelines and autonomous agents), you will help develop the "Collaborative Canvas" — the interface where human ingenuity meets artificial intelligence. You will not just be building standard dashboards;

you will be engineering complex,
AI-native interfaces alongside senior and principal engineers. You will tackle unique challenges in Generative UI
, real-time state synchronization, and browser-based code editing. You will help build the tools that define how our engineers interact with autonomous agents, contributing to a deeply integrated, multi-modal workspace.

This role requires strong frontend engineering skills, an interest in developer tooling, and a desire to build intuitive user interfaces in the age of AI.

• Develop the Agentic Workspace: Build and maintain core frontend features for the AI platform using React
  , Type Script , and Next.js
  , ensuring excellent performance and responsiveness.
• Contribute to the "Collaborative Canvas": Help implement a real-time, multi-player workspace where AI agents and humans can co-author artifacts. Work with Web Sockets and state-syncing technologies to manage shared state seamlessly.
• Implement "Generative UI": Build out a robust component registry and help develop the rendering engine that allows AI agents to dynamically generate interactive UI elements (charts, forms, checklists) on the fly.
• Visualize Intelligence: Create intuitive data visualizations allowing users to see why an AI agent made a decision, trace its sources, and inspect its reasoning via interactive diagrams.
• Partner with the Backend: Collaborate closely with Backend Engineers to consume complex APIs (GraphQL, Streaming JSON, Server-Sent Events) and bring agent outputs to life in the browser.
• Focus on Developer Experience (DX): Work with your "customers" (Pennymac engineers and product analysts) to understand their workflows and build elegant UI solutions that reduce friction.
• Uphold Frontend Standards: Write clean, modular, and well-tested code. Participate in code reviews, contribute to E2E/Integration testing, and help maintain our architectural standards.

Must-Haves:

• Bachelor’s Degree in Computer Science, HCI, or related engineering disciplines, or equivalent professional experience.
• Strong React & Type Script
  
  Skills:
  
  Proven experience (3-5+ years) building complex Single Page Applications (SPAs). Solid understanding of React fundamentals, hooks, context, and state management.
• Next.js
  
  Experience:
  
  Familiarity with modern Next.js architectures (App Router) and concepts like Server Components and progressive UI rendering.
• Interest in Real-Time Applications:
  
  Experience with or a strong desire to learn about building multi-user, real-time applications using Web Sockets
  , SSE
  , or state-syncing libraries.
• AI Integration
  
  Experience:
  
  Experience (or strong personal interest/projects) integrating LLM APIs (OpenAI, Anthropic, etc.) into frontend applications. Comfortable handling unstructured data and "streaming" UI responses.
• Data Visualization:
  
  Experience with visualization libraries (e.g.,
  D3.js
  , Recharts
  , React Flow
  , or Mermaid.js
  ) to render charts, graphs, or flow diagrams.
• A "Startup Mentality": Collaborative spirit, eagerness to learn, and adaptability. You are comfortable iterating quickly on an MVP based on user feedback.

Nice-to-Have (Bonus Points):

• Experience with AI SDKs: Familiarity with the Vercel…