Machine Learning Engineer, Model Evaluation

About Xenonstack XenonStack is a Data and AI Foundry for Agentic Systems, enabling enterprises to design, deploy, operate, and scale intelligent agents across digital and physical environments.

About Xenonstack XenonStack is a Data and AI Foundry for Agentic Systems, enabling enterprises to design, deploy, operate, and scale intelligent agents across digital and physical environments.

We Build Enterprise-grade Platforms Across The Agentic Stack

• Akira AI — Reasoning and agent orchestration. Turn models into collaborative, policy-governed agents that learn and act together.
• ElixirData — Agentic analytics intelligence. Explainable, decision-centric analytics for measurable business outcomes.
• NexaStack — Agentic infrastructure automation. Secure, compliant AI deployment across cloud, edge, and on-prem.
• MetaSecure — Trust, compliance and defense. Continuous assurance with AI-BOMs, risk scoring, and agentic security.

Our mission is to accelerate the world’s transition to AI + Human Intelligence by making agentic systems reliable, responsible, and enterprise-ready.

THE OPPORTUNITY

We are seeking an Machine Learning Engineer, Model Evaluation 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.

• 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 m