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Security Engineer Penetration Testing

Hallmark Global TechnologiesSan Jose, CA🇺🇸United StatesPosted 1 Sept 2026

Quick Overview

Seniority
Mid Senior
Work mode
On Site
Location
San Jose, CA, United States
Posted
Yesterday
AWSMachine LearningOWASPActive DirectoryAzureBashGoogle CloudGraphQLLLMPenetration TestingPowerShellPythonREST

Job Description

Job Title: Security Engineer Penetration Testing

Location: San Jose, CA Onsite

Contract

Role summary

We are seeking a highly skilled Security Engineer specializing in Penetration Testing to strengthen our o ensive security capabilities. This role is responsible for identifying vulnerabilities across applications, infrastructure, cloud environments, and emerging AI/ML systems, including Large Language Models (LLMs) and GenAI platforms. The ideal candidate combines deep technical pentesting expertise with hands-on experience in AI security, enabling proactive defense against sophisticated and evolving threats.

Key Responsibilities:

Application & API Security Testing

  • Perform black-box, gray-box, and white-box penetration testing of:
    • Web applications, APIs (REST/GraphQL), and mobile platforms

Identify vulnerabilities including:

  • Authentication/authorization flaws
  • Injection attacks
  • Business logic vulnerabilities
  • Session Management
  • Information Gathering
  • Data Validation, Governance and Transfer
  • Configuration Management

Conduct secure code reviews and validate SAST/DAST findings

Infrastructure & Network Penetration Testing

Execute penetration testing across:

  • Enterprise networks (internal/external)
  • Cloud platforms (AWS, Azure, Google Cloud Platform)
  • Hybrid environments

Perform:

  • Privilege escalation and lateral movement
  • Active Directory assessments (Kerberos, NTLM, etc.)

Identify misconfigurations and control weaknesses

AI/ML & GenAI Security Testing

Conduct security assessments on:

  • LLM-based applications and AI copilots
  • Machine learning models and pipelines

Perform:

  • Prompt injection and jailbreak testing
  • Data leakage and model abuse scenarios
  • Adversarial ML attacks (evasion, poisoning)

Assess:

  • RAG (Retrieval-Augmented Generation) pipelines
  • Model APIs, plugins, and agent frameworks
  • E ectiveness of AI guardrails and controls

Red Teaming & Adversary Simulation

Simulate real-world attack scenarios across:

  • Applications, infrastructure, and AI systems

Develop multi-stage attack chains combining:

  • Traditional and AI-specific techniques

Support purple team exercises with SOC and detection teams

Automation & AI-Driven Security Testing

Leverage AI tools to:

  • Automate vulnerability discovery
  • Generate test cases and attack payloads
    • Develop custom tools/scripts using:
  • Python, Bash, PowerShell, or Go

Enhance scalability and repeatability of pentesting processes

Reporting & Stakeholder Engagement

Deliver:

  • Executive-level summaries (CIO/CISO ready)
  • Detailed technical reports with reproduction steps

Provide:

  • Risk-based prioritization aligned to business impact
  • Actionable remediation guide

Collaborate with:

  • Engineering, Cloud, SOC, and DevOps teams

Required Qualifications

Experience

5+ years in penetration testing, red teaming, or o ensive security

Proven experience testing:

  • Web applications, APIs, and infrastructure

Hands-on exposure to cloud security and enterprise environments

Technical Skills

Strong knowledge of:

  • OWASP Top 10 / API Top 10
  • OWASP Top 10 LLM
  • Network and infrastructure pentesting
  • Identity and Active Directory exploitation

Experience with tools such as:

  • Burp Suite, Metasploit, Nmap
  • BloodHound, Mimikatz, Nessus

AI Security

Understanding of:

  • LLM architectures and GenAI use cases
  • RAG pipelines, embeddings, and vector databases

Experience with:

  • Prompt injection testing
  • AI red teaming or model security assessments

Exposure to:

  • LangChain, Semantic Kernel, or similar frameworks

Programming

Proficiency in:

  • Python (required)
  • Scripting (Bash/PowerShell)

Ability to develop:

  • Custom testing tools and exploit scripts

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