Software Engineer — Full Stack & AI Infrastructure

Software Engineer Full Stack & AI Infrastructure

Firmly · Forest Hills, Queens, NY · Onsite · Full-time

$120,000–$150,000/year

About Firmly

Firmly is building the Law Firm Operating System, an AI-native platform designed to replace the disconnected software, files, and manual workflows law firms rely on today.

A major part of the platform is the development of specialized AI systems built for specific legal and operational tasks, with secure access to a firm's documents, data, and internal knowledge.

The Role

We are looking for an engineer who can work across full-stack development, AI infrastructure, and production systems.

You will work directly with the founder, who leads product direction and architecture. Your job is to turn detailed requirements into reliable production software and help build the infrastructure behind Firmly's AI systems.

This is not just a web-development role. A major part of the job will involve open-source AI models, self-hosted inference, secure data access, sandboxing, retrieval systems, and AI infrastructure.

What You'll Do

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

The Stack

Application:

Next.js 15 · React 19 · TypeScript · Tailwind · shadcn/ui · PostgreSQL

AI / Infrastructure:

Open-source LLMs · RAG · Embeddings · Vector Search · Docker · Linux · GPU Inference · Sandboxing · Model Serving

The stack is not locked in. We want someone capable of evaluating technologies and making sound architectural decisions.

You're a Strong Fit If You

Have 3+ years of professional software engineering experience

Are strong in TypeScript, React, backend development, and PostgreSQL

Are comfortable with Linux, Docker, networking, deployment, and production infrastructure

Have experience deploying or working with open-source language models

Understand RAG, embeddings, semantic search, and document retrieval

Understand authentication, authorization, permissions, and data-access boundaries

Can design secure, sandboxed systems for AI execution

Can move between frontend, backend, database, infrastructure, and AI work

Know how to debug complex systems without saying, “that's not my layer”

Use AI coding tools effectively while still understanding and verifying the code they produce

Care about shipping software that is secure, tested, reliable, and actually works

Especially Valuable

Experience with technologies such as vLLM, llama.cpp, Ollama, SGLang, Llama, GLM, Qwen, Mistral, DeepSeek, pgvector, CUDA, GPU infrastructure, model quantization, fine-tuning, or agentic systems is a major plus.

Location

Full-time, onsite in Forest Hills, Queens, New York.

Compensation

$120,000–$150,000 per year, depending on experience and demonstrated technical ability.