Software Engineer — Full Stack & AI Infrastructure

Firmly is building an AI-native operating system for law firms to replace disconnected software, files, and manual workflows. The Software Engineer will develop and operate full-stack applications, AI infrastructure, retrieval systems, secure data access, and production systems across frontend, backend, databases, and infrastructure.

Responsibilities:

• Build and ship features in our Next.js, React, TypeScript, and PostgreSQL application
• Deploy and operate open-source LLMs
• Build specialized AI systems for narrowly defined legal and operational tasks
• Connect AI securely to firm documents, databases, and file repositories
• Build RAG, semantic search, embeddings, document ingestion, and retrieval pipelines
• Design permission-aware AI access to sensitive firm information
• Build sandboxed environments for AI tools, agents, and generated code
• Manage containers, model-serving infrastructure, deployments, and production issues
• Build and maintain authentication, permissions, sessions, APIs, and database systems
• Review and improve both human-written and AI-generated code
• Own problems from diagnosis through resolution