Christian's Portfolio

• Monitored, triaged, and investigated security alerts using enterprise SIEM and EDR platforms (Splunk, CrowdStrike), performing log analysis to identify true positives, prioritize severity, and escalate high-severity notables per established procedures to support day-to-day Security Operations Center (SOC) functions.
• Participated in incident response investigations spanning phishing, malware, business email compromise, and account compromise scenarios, using Microsoft Defender, Microsoft Entra ID, and Microsoft Purview to analyze indicators of compromise and support containment, remediation, and incident timeline documentation.
• Contributed to identity and access management reviews in Microsoft Entra ID, including Conditional Access policy validation and sign-in log analysis.
• Conducted vulnerability assessments and supported vulnerability management using Nucleus, incorporating threat intelligence to prioritize findings, validating and verifying results, coordinating remediation and mitigation efforts with IT teams, and tracking remediation status in Jira.
• Supported endpoint security operations through CrowdStrike, including host containment and remote remediation via PowerShell scripting, while automating incident response tasks through Fusion SOAR workflow development.
• Performed detection engineering in Splunk, creating, tuning, and modifying correlation searches and detection logic mapped to the MITRE ATT&CK framework to reduce false positives and improve alert accuracy.
• Configured and maintained security tools to established baselines, including Microsoft Entra Conditional Access policies, Palo Alto firewall rules, and CrowdStrike detection exclusions.
• Participated in firewall and network log architecture reviews using Palo Alto and Panorama, analyzing rule usage and traffic patterns to improve log filtering, ingest efficiency, and network visibility.
• Contributed to the development of a Shadow AI usage monitoring dashboard in Splunk, tracking AI application adoption, unique users, and usage trends to improve enterprise visibility into unsanctioned AI tool usage.
• Supported PCI DSS and HITRUST compliance audits by collecting and validating evidence for external auditors, and conducted risk assessments for new software prior to enterprise deployment.
• Helped maintain and improve internal security documentation, playbooks, and runbooks in Confluence, and supported the onboarding of a Managed Detection and Response (MDR) solution, collaborating with IT, security, and the vendor's team to strengthen enterprise security processes.

Skills Applied: Incident Response, SIEM/EDR Monitoring (Splunk, CrowdStrike), Vulnerability Management, Detection Engineering, Identity & Access Management, Security Automation (SOAR), Firewall & Network Security, PCI DSS / HITRUST Compliance

• Conducted undergraduate research in network security focused on radio frequency fingerprinting (RFF), physical-layer device authentication, and adversarial wireless signal analysis.
• Contributed to early survey research on whether RF fingerprints are truly unique but unclonable, reviewing work on transmitter hardware impairments, fingerprint feature types, channel effects, CNN-based classification, and GAN-based adversarial signal generation.
• Gained hands-on experience with HackRF One, USRP N200, GNU Radio Companion, and 802.11 Wi-Fi signal processing by building and modifying flowgraphs for wireless reception, transmission, frame decoding, and MAC address extraction.
• Configured and debugged SDR capture pipelines, including GNU Radio flowgraphs, UHD/USRP networking, Wi-Fi decoding blocks, file sinks, and scripts for organizing captured frames by MAC address.
• Captured over-the-air 802.11 Wi-Fi data across multiple campus locations, including 8.5K+ decoded frames, 300+ unique MAC addresses, and device-specific datasets filtered for downstream RF fingerprinting experiments.
• Ran captured RF data through a CNN classifier and GAN-based signal generation pipeline to evaluate closed-set model performance against unknown real devices and synthetic attacker-like signals.
• Prepared known, unknown, and attack-device data splits to support open-set recognition experiments and evaluate classifier behavior across real and synthetic RF samples.

Skills Applied: RF Fingerprinting & Device Authentication, IEEE 802.11 Wireless Security, Software-Defined Radio (HackRF One, USRP N200, GNU Radio Companion), Python, Adversarial Machine Learning (GANs), CNN Classification, Open-Set Recognition, Signal Processing

Senior Capstone | UCSC Procurement and Supply Chain Services Department

• Developed a full-stack compliance automation platform for UCSC Financial Affairs to help auditors review OneCard transaction data more efficiently.
• Built application workflows for uploading Excel transaction files, parsing and normalizing records, running rule-based and AI-assisted compliance checks, reviewing flagged purchases, saving auditor notes, managing uploaded batches, and exporting reviewed results.
• Combined JSONLogic-based compliance rules with Vertex AI/Gemini evaluation to flag high-risk and ambiguous transactions and provide reviewer-facing explanations.
• Contributed to core platform features including transaction review, batch management, role-based access behavior, export functionality, auditor feedback handling, and AI prompt iteration.
• Collaborated directly with UCSC procurement and financial stakeholders to refine compliance logic, improve exception handling, and align the platform with real audit workflows.
• Supported a project targeting 50,000+ annual OneCard transactions, reaching 72.5% accuracy on auditor-validated complex test batches.

Skills Applied: React, TypeScript, Firebase, Vertex AI / Gemini, JSONLogic, Full-Stack Development, Compliance & Audit Support, Stakeholder Collaboration