Senior Backend Software Developer – AI / LLM
Major US banking institution · Cupertino, CA
- Location
- Cupertino, CA · Hybrid
- Salary band
- Band not stated
- Type
- Contract
- Level
- Senior
- Work authorization
- Not stated
Stack
Python · FastAPI · PostgreSQL · OpenAI · LLM · NER · async/await · Pydantic · pytest · embeddings · Git · GitLab · CI/CD · React · TypeScript · Agile/Scrum · document intelligence · prompt optimization · TanStack · Vite
About the role
Senior Backend Software Developer – AI / LLM Location: Hybrid - Cupertino, CA 1 yr contract with ext. Position Overview We are seeking a Senior Backend Software Developer to join our AI engineering team and help build AI-powered applications for unstructured document processing and Named Entity Recognition (NER). The platform leverages Python, FastAPI, PostgreSQL, Large Language Models (LLMs), embeddings, and document intelligence technologies to extract meaningful information from complex documents. This role will focus primarily on backend development, AI/LLM integrations, system reliability, and evaluation while collaborating closely with frontend and cross-functional engineering teams. This is a highly technical role requiring strong software engineering fundamentals, hands-on Python development, and experience building production applications using LLMs. Key Responsibilities - Design, develop, and maintain production-grade Python applications and FastAPI services. - Build asynchronous APIs and backend services using Python 3.10+ and async/await patterns. - Design and optimize PostgreSQL schemas, queries, indexes, and database migrations. - Integrate with OpenAI, Clienture OpenAI, embedding models, and other LLM platforms. - Develop AI-powered capabilities for document processing, information extraction, and NER applications. - Design and implement LLM evaluation frameworks, including golden datasets, evaluation metrics, and regression testing. - Work on prompt optimization, model evaluation, and drift detection. - Build reliable integrations with document intelligence and AI services. - Develop comprehensive unit and integration test suites using pytest. - Maintain high standards for code quality through type annotations, linting, automated testing, and code reviews. - Participate in architecture discussions, technical design reviews, and implementation decisions. - Collaborate with frontend, AI/ML, DevOps, and distributed engineering teams. - Troubleshoot production issues and improve application reliability, performance, and scalability. - Contribute to Agile/Scrum planning, estimation, and delivery. Required Qualifications - 5+ years of professional software development experience. - Strong proficiency in Python 3.10+. - Hands-on experience with FastAPI and asynchronous programming. - Strong experience with PostgreSQL, including schema design, query optimization, and migrations. - Experience integrating with LLM APIs, such as OpenAI, Clienture OpenAI, or similar platforms. - Experience building AI-powered applications or LLM-based features. - Experience developing automated unit and integration tests using pytest. - Experience with LLM evaluation, golden datasets, or model/prompt evaluation. - Strong understanding of software engineering practices including: - Type annotations - Linting - Automated testing - Code reviews - Git-based development workflows - Strong communication skills and the ability to work independently in a distributed engineering environment. Preferred Qualifications - Experience with Pydantic and dependency injection patterns. - Familiarity with repository-pattern architectures. - Understanding of LLM tokenization, caching, embeddings, and AI infrastructure. - Experience with prompt optimization and LLM evaluation frameworks. - Experience with drift detection and AI quality monitoring. - Familiarity with document intelligence or document extraction technologies. - Experience building an AI agent harness from scratch. - Understanding of LLM architecture and the major components involved in an LLM-powered application. - Experience with React/TypeScript or modern frontend technologies is a plus. Nice-to-Have: Full-Stack Exposure While the primary focus of this role is backend engineering, exposure to modern frontend technologies is beneficial, including: - React - TypeScript - TanStack - Vite - Modern component libraries Technical Environment Backend: Python, FastAPI, Pydantic, async/await Database: PostgreSQL AI/LLM: OpenAI, Clienture OpenAI, embeddings, LLM evaluation Document Processing: Document Intelligence, unstructured document extraction, NER Testing: pytest, unit testing, integration testing, golden datasets Development: Git, GitLab, CI/CD Frontend Exposure: React, TypeScript, TanStack, Vite Methodology: Agile/Scrum Interview Process - Take-home technical assessment — approximately 1 hour of work, completed over several days. - 2–3 technical interview rounds, approximately 60 minutes each. - Video interviews conducted through Microsoft Teams. - Interview process will include hands-on coding, system/technical discussions, Python/FastAPI, database, and LLM-related topics. Work Environment The role works with a distributed engineering team, including U.S.-based and offshore engineering resources. Strong communication, ownership, and the ability to work independently are important for success.
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