Machine Learning Engineer, Model Evaluation

About Xenonstack
XenonStack is the fastest-growing Data and AI Foundry for Agentic Systems, enabling enterprises to gain real-time and intelligent business insights.
We Deliver Innovation Through

• Agentic Systems for AI Agents → akira.ai
• Vision AI Platform → xenonstack.ai
• Inference AI Infrastructure for Agentic Systems → nexastack.ai
  

Our mission is to accelerate the worlds transition to AI + Human Intelligence by making AI agents reliable, explainable, and enterprise-ready.
THE OPPORTUNITY
We are seeking an LLM Reliability & Evaluation Engineer to ensure that large language models (LLMs) and agentic AI systems meet enterprise-grade standards of accuracy, safety, and trustworthiness.
This role focuses on evaluating, benchmarking, and stress-testing LLMs in real-world workflows, building frameworks for reliability, robustness, and continuous improvement. If you thrive at the intersection of AI research, applied testing, and responsible deployment, this is the role for you.
Key Responsibilities

• Evaluation Frameworks
• Design and implement LLM evaluation pipelines covering accuracy, robustness, safety, and bias.
• Develop automated systems for benchmarking models on enterprise-relevant tasks.
• Reliability Engineering
• Conduct stress tests, adversarial testing, and edge-case evaluations.
• Build tools to measure latency, consistency, and error recovery in multi-turn interactions.
• Metrics & Monitoring
• Define KPIs such as factual accuracy, hallucination rate, toxicity, and compliance alignment.
• Establish real-time monitoring for drift, anomalies, and performance regressions.
• Collaboration & Alignment
• Partner with ML engineers, product managers, and domain experts to align evaluation with business objectives.
• Work with Responsible AI teams to implement ethical, explainable, and compliant evaluation practices.
• Continuous Improvement
• Feed insights from evaluation into fine-tuning, RLHF/RLAIF pipelines, and model selection.
• Maintain a central repository of test cases, benchmarks, and evaluation results.
• Research & Innovation
• Stay current with state-of-the-art LLM evaluation techniques, from academic benchmarks to applied enterprise metrics.
• Explore automated evaluation using agentic test harnesses and synthetic data generation.
  

Skills & Qualifications
Must-Have

• 3–6 years in AI/ML, NLP, or applied model evaluation.
• Strong understanding of LLM architectures, prompt engineering, and failure modes.
• Hands-on with evaluation frameworks (Eval harnesses, Ragas, OpenAI Evals, DeepEval).
• Proficiency in Python and libraries like LangChain, LangGraph, LlamaIndex, Hugging Face.
• Experience with vector databases, RAG pipelines, and knowledge graph integration.
• Familiarity with bias/fairness testing and Responsible AI frameworks.
  

Good-to-Have

• Experience with reinforcement learning (RLHF, RLAIF) and reward modeling.
• Exposure to agentic evaluation frameworks (multi-agent stress testing, synthetic user simulators).
• Knowledge of compliance and safety requirements for BFSI, GRC, or SOC use cases.
• Contributions to open-source evaluation libraries or research papers.
  

WHY SHOULD YOU JOIN US

• Agentic AI Product Company
  

Ensure reliability in cutting-edge AI platforms that are redefining enterprise adoption.

• A Fast-Growing Category Leader
  

Be part of one of the fastest-growing AI Foundries, powering Fortune 500 enterprises with trustworthy AI.

• Career Mobility & Growth
  

Grow into roles such as AI Systems Architect, Responsible AI Engineer, or Reliability Engineering Lead.

Looking to get Placed? Try our Placement Guarantee Plan

Get Hired
• Global Exposure
  

Work on enterprise-scale evaluation challenges across BFSI, Healthcare, Telecom, and GRC.

• Create Real Impact
  

Your evaluations will directly shape production-grade AI agents used in mission-critical systems.

• Culture of Excellence
  

Our values — Agency, Taste, Ownership, Mastery, Impatience, and Customer Obsession — empower you to innovate fearlessly.

• Responsible AI First
  

Join a company that prioritizes trustworthy, explainable, and compliant AI.
XENONSTACK CULTURE – JOIN US & MAKE AN IMPACT!
At XenonStack, we believe in shaping the future of intelligent systems. We foster a culture of cultivation built on bold, human-centric leadership principles, where deep work, simplicity, and adoption define everything we do.
Our Cultural Values

• Agency – Be self-directed and proactive.
• Taste – Sweat the details and build with precision.
• Ownership – Take responsibility for outcomes.
• Mastery – Commit to continuous learning and growth.
• Impatience – Move fast and embrace progress.
• Customer Obsession – Always put the customer first.
  

Our Product Philosophy

• Obsessed with Adoption – Making AI accessible, reliable, and enterprise-ready.
• Obsessed with Simplicity – Turning complex evaluation challenges into seamless, automated frameworks.
  

Be part of our mission to accelerate the worlds transition to AI + Human Intelligence — by making AI agents not just powerful, but trustworthy and reliable.