Essential Work Samples for Hiring Top Application Security Engineers

Application security engineers play a critical role in protecting an organization's digital assets and ensuring the security of software applications throughout their lifecycle. As cyber threats continue to evolve in sophistication, hiring the right security talent has never been more important. The challenge lies in effectively evaluating candidates beyond their certifications and interview responses.

Traditional interviews often fail to reveal a candidate's true capabilities in identifying vulnerabilities, implementing security controls, and collaborating with development teams. While a candidate may articulate security concepts well, their practical skills in applying these concepts might not match their theoretical knowledge. This disconnect can lead to costly hiring mistakes.

Work samples provide a window into how candidates approach real-world security challenges. By observing candidates perform tasks similar to those they'll encounter on the job, hiring managers can gain valuable insights into their technical abilities, problem-solving approaches, and communication skills. These practical exercises reveal not just what candidates know, but how they apply that knowledge.

For application security engineers specifically, work samples should evaluate core competencies like vulnerability assessment, secure coding practices, threat modeling, and security architecture design. The following exercises are designed to comprehensively assess these skills while providing candidates with a realistic preview of the role's responsibilities.

Activity #1: Code Review for Security Vulnerabilities

This exercise evaluates a candidate's ability to identify security vulnerabilities in code, a fundamental skill for application security engineers. It tests their knowledge of common security flaws, secure coding practices, and their ability to communicate findings effectively to development teams.

Directions for the Company:

• Prepare a code sample (approximately 100-200 lines) containing 5-7 deliberate security vulnerabilities of varying difficulty. Include issues like SQL injection, XSS vulnerabilities, insecure authentication, and improper error handling.
• Provide the code in a format that's easy to review (e.g., GitHub repository, PDF, or shared document).
• Allow candidates 45-60 minutes to complete the review.
• Have a senior security engineer available to discuss the findings afterward.

Directions for the Candidate:

• Review the provided code sample and identify as many security vulnerabilities as possible.
• For each vulnerability found, document:
• The location in the code
• The type of vulnerability
• The potential impact if exploited
• Recommended remediation steps
• Prioritize the vulnerabilities based on risk level.
• Be prepared to explain your findings and recommendations as if you were communicating with a development team.

Feedback Mechanism:

• After the candidate presents their findings, provide feedback on one vulnerability they identified well (including their remediation approach) and one vulnerability they missed or misunderstood.
• Give the candidate 10 minutes to reconsider the missed vulnerability and propose a solution, or to improve their initial remediation approach.

Activity #2: Threat Modeling Exercise

This exercise assesses a candidate's ability to think systematically about security threats and risks, a crucial skill for proactively identifying and addressing security concerns before they become vulnerabilities.

Directions for the Company:

• Create a simplified architecture diagram of a web application with various components (e.g., web servers, databases, authentication services, third-party integrations).
• Include a brief description of the application's purpose, user types, and data handled.
• Provide the candidate with the STRIDE threat modeling framework if they're not already familiar with it.
• Allow 45-60 minutes for the exercise.

Directions for the Candidate:

• Review the provided architecture diagram and application description.
• Create a threat model that identifies potential security threats to the system using the STRIDE framework (Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, Elevation of Privilege).
• For each identified threat:
• Describe the potential attack vector
• Assess the potential impact
• Suggest security controls to mitigate the risk
• Prioritize the threats based on risk level (considering likelihood and impact).
• Be prepared to present and discuss your threat model.

Feedback Mechanism:

• Provide feedback on the comprehensiveness of the threat model and the effectiveness of the proposed mitigations.
• Highlight one threat the candidate identified particularly well and one area where their analysis could be improved.
• Allow the candidate 10 minutes to refine their approach to the area needing improvement.

Activity #3: Security Incident Response Simulation

This exercise evaluates a candidate's ability to respond to security incidents effectively, demonstrating their analytical thinking, decision-making under pressure, and communication skills during crisis situations.

Directions for the Company:

• Create a detailed scenario of a security incident, such as a potential data breach, suspicious system behavior, or a reported vulnerability.
• Include relevant logs, alerts, or other artifacts that the candidate would need to analyze.
• Prepare a list of stakeholders the candidate might need to communicate with during the incident.
• Allow 45-60 minutes for the exercise.

Directions for the Candidate:

• Review the security incident scenario and supporting materials.
• Develop an incident response plan that includes:
• Initial assessment of the situation
• Steps to contain and investigate the incident
• Methods to identify the root cause
• Remediation actions
• Communication plan for different stakeholders (executives, technical teams, customers)
• Document your findings and recommendations in a brief incident report.
• Be prepared to role-play a briefing to technical and non-technical stakeholders.

Feedback Mechanism:

• Provide feedback on the candidate's incident response approach, focusing on their technical analysis and communication strategy.
• Highlight one aspect they handled well and one area where their response could be improved.
• Give the candidate 10 minutes to revise their approach to the area needing improvement.

Activity #4: Security Architecture Design Challenge

This exercise assesses a candidate's ability to design secure systems and integrate security controls into application architecture, demonstrating their knowledge of security principles, frameworks, and best practices.

Directions for the Company:

• Create a scenario for a new application or feature that needs security architecture design (e.g., a new payment processing system, user authentication service, or data storage solution).
• Provide business requirements, constraints, and compliance considerations.
• Include any existing architecture components that need to be integrated with.
• Allow 60 minutes for the exercise.

Directions for the Candidate:

• Review the provided scenario and requirements.
• Design a security architecture that addresses the security needs of the application, including:
• Authentication and authorization mechanisms
• Data protection controls (encryption, access controls)
• Security monitoring and logging
• Secure communication channels
• Compliance with relevant standards (e.g., OWASP, NIST, PCI DSS)
• Create a diagram or visual representation of your security architecture.
• Document the rationale behind your design decisions and any assumptions made.
• Be prepared to present and defend your design.

Feedback Mechanism:

• Provide feedback on the security architecture design, focusing on its completeness, practicality, and alignment with security best practices.
• Highlight one strong aspect of the design and one area that could be improved.
• Allow the candidate 15 minutes to refine the identified area of their design based on the feedback.

Frequently Asked Questions

How long should we allocate for these work samples in our interview process?

Each exercise is designed to take 45-60 minutes, plus time for feedback and discussion. We recommend selecting 1-2 exercises that best align with your specific needs rather than attempting all four in a single interview cycle. The exercises can be conducted during an onsite interview or as a take-home assignment with a follow-up discussion.

Should we expect candidates to complete these exercises perfectly?

No. These exercises are designed to assess problem-solving approaches and thought processes, not just correct answers. Look for candidates who demonstrate sound security principles, methodical approaches, and the ability to learn from feedback, even if they don't identify every vulnerability or threat.

How should we evaluate candidates who use different methodologies than what we expected?

Security professionals often develop unique approaches based on their experience. Evaluate the effectiveness of their methodology rather than strict adherence to a specific framework. If their approach is sound and addresses the core security concerns, consider it a demonstration of valuable diverse thinking that could benefit your team.

Can these exercises be adapted for different seniority levels?

Yes. For junior roles, simplify the scenarios and provide more guidance. For senior roles, increase the complexity of the vulnerabilities, add architectural challenges, or include business constraints that require security trade-offs. You can also adjust expectations for the depth and breadth of the solutions based on experience level.

How do we ensure these exercises don't disadvantage candidates from different backgrounds?

Provide clear instructions and necessary context for all exercises. Allow candidates to ask clarifying questions before beginning. Consider offering a choice between exercises that test the same skills but in different contexts, allowing candidates to select scenarios where they feel most comfortable demonstrating their abilities.

Should we share these exercises with candidates in advance?

For some exercises, particularly the more complex ones like the Security Architecture Design Challenge, providing the scenario in advance can allow candidates to showcase their best work without time pressure. For others, like the Security Incident Response Simulation, real-time problem-solving is part of what you're evaluating. Consider which approach best matches the actual job requirements.

Implementing these work samples will significantly improve your ability to identify top application security talent. By observing candidates tackle realistic security challenges, you'll gain insights into their technical skills, problem-solving approaches, and communication abilities that traditional interviews simply cannot reveal.

For more resources to enhance your hiring process, check out Yardstick's AI Job Descriptions, AI Interview Question Generator, and AI Interview Guide Generator.

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