AI Software Engineer (LLM Systems)

About the company

About Cosign.ai Labs, Inc.
Cosign.ai Labs is building the control layer for AI-powered decision making.

Most AI products today generate answers. Thats not the hard part anymore. The hard part is deciding what should be done, what risks are acceptable, and when humans should step in. Thats where Cosign comes in.

We build systems that sit on top of large language models and turn them into structured, governed workflows. Instead of asking AI for opinions, our platform encodes rules, judgment frameworks, and escalation paths so users can actually act on AI outputs with confidence.

Our first product focuses on contracts. Cosign helps individuals and companies analyze, draft, and negotiate agreements using AI without needing to be legal experts. Under the hood, we combine LLM reasoning with deterministic logic to produce structured outputs that are consistent, auditable, and aligned with user-defined risk tolerance.

Were not trying to replace professionals. Were building tools that let people operate at a much higher level, with AI handling the heavy lifting and Cosign ensuring it stays within guardrails.

Role details

Role Summary
Design and build the core AI systems powering Cosign.ai. This includes LLM integrations, agent workflows, and scalable backend systems.

What Youll Do

Build and optimize LLM-powered features (analysis, drafting, automation)
Design agentic workflows combining reasoning + deterministic systems
Integrate APIs, embeddings, vector databases, and retrieval systems
Improve latency, cost efficiency, and reliability of AI systems
Work closely with product to ship fast and iterate based on usage
Stay on top of new models, tools, and capabilities (and actually use them)
Requirements

Strong experience in backend engineering (Python, Node, etc.)
Deep familiarity with LLMs, prompt design, RAG systems, and agent frameworks
Experience with real-world AI product deployment (not just demos)
Ability to balance speed vs. quality in a startup environment
Mild obsession with making things work better, faster, cheaper

Compensation

Base Salary
$140K $200K

Equity
1.0% 3.0%