I review AI agents for prompt-injection risks, unsafe tool calls, and silent evaluation failures. Deliverables: threat model, reproducible attack cases, severity-ranked findings, fixes, and pytest regression gates. Security reviews start at $100/hour; general AI, evaluation and data engineering: $80/hour. GitHub: https://github.com/arthi-arumugam-git. Skills: AI agents, LLM evaluation, prompt injection / AI security, Python, data engineering, BigQuery, Azure, MCP. EXPERIENCE: Lumen Technologies (Oct 2025 – Nov 2026) — Informatics Consultant, Network Engineering, Technology & Security (Remote): shipped a Vertex AI/Gemini agent for BigQuery SQL optimisation with structured-output validation before production DDL; cut bytes scanned 94% (565 MB to 35 MB). Migrated Oracle PL/SQL to BigQuery for the Quantum Fiber divestiture to AT&T; owned PUC reporting across eight US states; automated a 3,800-cell daily report from 45 minutes to 30 seconds. CodeSizzler — Data Analyst, AI & Cloud Platform Engineering (Remote, Jan 2024–Oct 2025): designed Walgreens supply-chain architecture on Microsoft Fabric OneLake with scikit-learn anomaly detection across 200+ stores: stockouts down 30%, inventory cost down 20%. Architected Grab real-time ingestion on Azure Data Factory, Synapse and Power BI. Delivered healthcare Snowflake platforms, manufacturing SQL optimisation, and a seven-unit ABARTA rollout with $42K annual saving. Network Rail — Project Management Assistant (United Kingdom, Hybrid, Apr–Dec 2023): Excel/Power BI/IRIS KPI reporting, surfaced 12 high-risk safety issues, automated SharePoint/Power Automate reporting to reduce manual effort 30%. Cognizant — Programming Analyst Trainee (Chennai, India, Dec 2019–May 2020): six-month Core Java, Spring Boot, HTML/CSS and SQL programme; built a grocery-shopping prototype with MySQL. EDUCATION: M.Sc. Management (Business Specialisation), Queen Mary University of London, 2021–2022. School of Business Scholarship. Thesis: ad personalisation, data privacy and consumer behaviour. B.Tech Information Technology, St. Joseph’s College of Engineering, Anna University, 2016–2020. 8.23/10. Thesis: real-time cyberbullying detection using NLP and Naive Bayes. CERTIFICATIONS: Microsoft Power BI Data Analyst Associate — 2024; Microsoft Azure Data Engineer Associate — 2024; Google Cloud Professional Data Engineer — 2024; Microsoft Fabric Data Engineer Associate — 2025.