Software Engineer - Agent Eval & Harness
Company: AryaXAI
Location: Mumbai, Maharashtra (Remote)
Type: Full-time
Remote: Yes
Posted: 2026-08-01
About this role
Lexsi Labs is the leading frontier AI lab focused on building aligned, interpretable, and safe superintelligent systems. While that is the vision, the mission is to build safety aware autonomous systems in the extreme near term. Our research work spans areas like AI alignment methodologies, interpretability-led system design, and foundational model research across structured, tabular, and new autonomous system designs. We published about 25+ papers in the past 15 months across leading conferences including ICLR, ICML, WWW, IJCNN, MICCAI and EurIPS. Our labs are located in India (Mumbai and remote), Paris, and London.
We operate with a flat structure, high autonomy, and a strong bias toward engineers who take full ownership of what they build, from architecture to production behavior.
## The Role
Our current sprint on building autonomous systems for complex problems, across software engineering, data science, and AI research, involves building the harness, execution substrate and evaluation system, and each is designed to run inside a customer's environment rather than ours.
This role sits underneath all three agents. The coding agent, the data science agent and the AI engineering agent look different from the outside, but they are the same system underneath: a loop that plans, acts, observes, recovers, and knows when to stop. You will build that shared layer, and the evaluation system that tells us whether any change to it made things better. Both halves matter equally. A harness we cannot measure is a harness we cannot improve.
## What you'll work on:
Harness
- The core agent loop and its execution model, covering orchestration, concurrency, sub-agent coordination, cancellation, timeouts, checkpointing and resume.
- Context and state management for long-running tasks, including retention, compaction, and how an agent reasons over what it has already done.
- The shared tool protocol, its schemas, versioning, and the internal libraries every agent team...