Engineering · Remote (US time zone overlap)
We're hiring a Senior AI Engineer to own and expand Lexsy's AI infrastructure. You'll build the systems that power our AI agents — from LLM integration and tool orchestration to guardrails, data isolation, and production reliability.
This isn't a research role. You'll ship production AI systems that serve real clients and handle real legal workflows. Every day.
About Lexsy
Lexsy.ai is the legal OS for companies — AI agents getting legal work done around the clock, human attorney in the loop, embedded into the company's tech stack from day one.
Lexsy starts as the company's first legal hire with a network of specialists — handling formation, fundraising, employment, and compliance. As the company scales, Lexsy becomes the system of record and command center for the company's human GC to manage outside counsel.
What You'll Build
- AI Agent Infrastructure: Design and build the repeatable agent framework that powers Lexsy's COO, Lawyer, CTO, and Growth agents.
- LLM Integration & Orchestration: Multi-model architecture (Claude, GPT, Gemini) with intelligent fallback, context management, and cost optimization.
- Tool & API Integration: Build and maintain integrations with 30+ external services (Gmail, Slack, Notion, Calendar, financial APIs, legal tools) via MCP and direct APIs.
- Guardrails & Safety: Human-in-the-loop approval gates, data isolation, audit logging, and compliance enforcement at the framework level.
- Production Systems: Monitoring, alerting, reliability engineering for AI systems that serve paying clients 24/7.
- Platform Features: AI-powered client-facing features — cap table management, virtual data rooms, Word document generation and redlining, workflow automation, intelligent routing, and investor reporting tools.
What We're Looking For — Required
- 5+ years of software engineering experience with production systems at scale.
- Strong experience with LLM/AI integration in production (not just prototypes).
- Full-stack capability: you can build the API, the integration, and the UI.
- Experience with Next.js, TypeScript, and PostgreSQL (we use Supabase).
- Understanding of LLM reliability patterns — when to use AI vs. deterministic logic, how to handle hallucinations, context window management.
- Startup comfort — you've worked in environments where you own problems end-to-end.
- Strong debugging skills under production pressure.
Preferred
- Experience building multi-agent systems or AI agent frameworks.
- Familiarity with MCP (Model Context Protocol) or similar tool-use architectures.
- Experience with cloud platforms (Railway, Vercel, AWS, or GCP).
- Background in regulated industries (legal, healthcare, fintech) where guardrails matter.
- Open source contributions or public technical writing.
- Experience with real-time systems (webhooks, streaming, event-driven architectures).
- Familiarity with financial/legal data structures (cap tables, equity instruments, corporate records) and document processing (Word/DOCX generation, redlining, version tracking).
Compensation
- Base salary plus equity.
- Remote-first (US time zone overlap required).
