React Full Stack - Senior Software Engineer

Marsh McLennan•White Plains, NY

About The Position

As a Senior Software Engineer on the Marsh Agency Software Engineering team, you will design, build, and evolve full-stack capabilities for an AI-powered insurance document analysis platform. You will partner with product, design, and engineering colleagues to translate complex business needs into secure, reliable experiences. The platform supports document processing, coverage-gap analysis, quote comparison, and real-time progress flows. You will help raise engineering standards through code reviews, automated testing, observability, and technical mentorship. Marsh Agency helps people and organizations manage risk and prepare for the future through insurance, benefits, retirement, and wealth management strategies. Its work emphasizes proactive service, data-driven insights, and helping clients understand how global events affect local decisions. The role offers hybrid or remote work. The applicable base salary range is $106,000 to $159,500, with potential eligibility for performance-based incentives. Compensation is determined case by case based on factors including experience, skills, training, location, certifications, and education.

Requirements

Strong experience building modern React applications with TypeScript, component-based UI design, and client-side API integration.
Professional experience developing Python services with FastAPI and designing RESTful APIs, background processing, and asynchronous workflows with Celery.
Ability to design secure, scalable systems integrating with identity platforms, third-party APIs, OCR/document-processing services, and LLM-powered workflows.
Experience with cloud-native deployment patterns, containers, CI/CD, monitoring, and production operations; AWS and Kubernetes/EKS experience is highly relevant.
Strong communication, collaboration, problem-solving, and technical leadership skills, including a track record of mentoring engineers and delivering high-quality work.
Hands-on experience with document-oriented or distributed data platforms such as MongoDB, Redis, and Amazon S3.

Nice To Haves

Experience with Mastra, LLM orchestration, prompt/tool design, or AI agent workflows.
Experience with Server-Sent Events, MongoDB change streams, OCR/document parsing, or browser-based WASM processing.
Familiarity with Microsoft Entra ID/MSAL, infrastructure as code, or observability platforms such as Datadog.

Responsibilities

Design, build, and evolve full-stack capabilities for an AI-powered insurance document analysis platform.
Partner with product, design, and engineering colleagues to turn business needs into secure, reliable experiences.
Contribute to document processing, coverage-gap analysis, quote comparison, and real-time progress flows.
Participate in thoughtful code reviews and automated testing.
Support observability and production operations.
Mentor engineers and provide technical leadership.