What is a Security Engineer at Aircall?

As a Staff Security Engineer, Product Security at Aircall, you are the primary defender and strategic architect of our core communication platforms. Aircall is revolutionizing the cloud telephony space by seamlessly integrating voice communications with the business tools our customers use every day. In this role, you are not just finding vulnerabilities; you are building a resilient, scalable security culture that protects millions of real-time voice interactions, sensitive customer data, and complex API integrations.

Your impact extends across the entire product ecosystem. You will work closely with engineering and product teams to secure our web applications, backend services, and cloud infrastructure. Because Aircall handles highly sensitive VoIP data and integrates with massive platforms like Salesforce and HubSpot, the security challenges you face will be uniquely complex. You will be expected to balance rigorous security standards with the high-performance, low-latency requirements of real-time communication.

This is a senior, highly strategic position. As a Staff Security Engineer, you will operate at a high level of autonomy, influencing the technical roadmap and mentoring other engineers. You will define how we approach threat modeling, shape our DevSecOps pipelines, and ensure that security is built into our products by design, rather than bolted on as an afterthought. Expect a dynamic environment where your technical depth and leadership will directly shape the trust our customers place in Aircall.

Common Interview Questions

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Getting Ready for Your Interviews

Preparing for a senior security role at Aircall requires a strategic mindset. We are looking for candidates who can seamlessly blend deep technical expertise with pragmatic, business-enabling problem-solving. You should approach your preparation by mastering the following key evaluation criteria:

Role-Related Knowledge – This evaluates your deep technical expertise in Product Security, application security (AppSec), and cloud infrastructure. Interviewers will look for your mastery of secure coding practices, vulnerability management, and modern authentication protocols. You can demonstrate strength here by fluently discussing how you have secured complex, cloud-native applications and mitigated advanced attack vectors.

Problem-Solving Ability – We want to see how you approach ambiguity and structure complex security challenges. In the context of Aircall, this often means conducting threat models on new features or designing secure architectures for real-time data flows. You will excel by showing a logical, methodical approach to identifying risks and proposing scalable, pragmatic mitigations.

Leadership and Influence – As a Staff Security Engineer, your ability to lead without direct authority is critical. We evaluate how you drive security initiatives, mentor peers, and influence cross-functional teams like engineering and product. Strong candidates will share concrete examples of how they have championed a security-first culture and successfully negotiated security requirements with product managers.

Culture Fit and Values – Aircall thrives on collaboration, transparency, and continuous learning. Interviewers will assess how you navigate conflict, handle mistakes, and collaborate with developers. You can stand out by demonstrating empathy for engineering teams and framing security as an enabler rather than a roadblock.

Interview Process Overview

The interview process for a Staff Security Engineer at Aircall is rigorous, collaborative, and designed to evaluate both your technical depth and your strategic vision. You will begin with an initial recruiter screen to align on your background, expectations, and the core requirements of the role. This is followed by a hiring manager interview, which focuses heavily on your past experiences, your approach to product security, and your alignment with Aircall’s mission.

As you progress to the technical rounds, expect deep dives into architecture, threat modeling, and application security. Unlike processes that rely on obscure trivia, our technical interviews are highly practical. You will be asked to review architectures, identify flaws in system designs, and discuss how you would implement security controls in a modern cloud environment. We prioritize your thought process, your ability to communicate risks clearly, and your pragmatism in finding solutions.

The final stages involve cross-functional and leadership interviews. You will meet with senior engineering leaders and peers to discuss how you influence teams, drive security culture, and handle pushback. Throughout the process, Aircall emphasizes a conversational, two-way dialogue; we want you to interview us just as much as we are interviewing you.

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This visual timeline outlines the typical progression from your initial screening calls through the technical deep-dives and final leadership rounds. Use this to pace your preparation, ensuring you review deep technical concepts early on while reserving time later to refine your behavioral and leadership narratives. Note that the exact sequence of technical rounds may shift slightly depending on interviewer availability.

Deep Dive into Evaluation Areas

To succeed in the Aircall interview process, you must demonstrate mastery across several core domains. Below is a breakdown of the primary evaluation areas, what they entail, and how you can prepare.

Threat Modeling and Architecture Review

This area is critical because Aircall continuously ships new features and integrations that must be secure by design. Interviewers will evaluate your ability to look at a complex system, identify potential threat vectors, and propose robust security controls. Strong performance means you can systematically break down an architecture, prioritize risks based on business impact, and design pragmatic defenses.

Be ready to go over:

• Data flow analysis – Mapping how sensitive data (like PII or VoIP streams) moves through a system and identifying trust boundaries.
• Threat frameworks – Utilizing methodologies like STRIDE or PASTA to systematically uncover vulnerabilities in proposed designs.
• Mitigation strategies – Designing scalable security controls such as rate limiting, encryption in transit/at rest, and zero-trust principles.
• Advanced concepts (less common) – Securing WebRTC architectures, voice-specific attack vectors (like SIP toll fraud), and complex microservices mesh security.

Example questions or scenarios:

• "Walk me through how you would threat model a new integration between Aircall and a third-party CRM like Salesforce."
• "If we are designing a new real-time transcription service for voice calls, what are the primary security risks, and how would you mitigate them?"
• "Describe a time you found a fundamental architectural flaw late in the development lifecycle. How did you handle it?"

Application Security and Vulnerability Management

As a Product Security expert, you are the last line of defense against application-layer attacks. This area tests your knowledge of common vulnerabilities, secure coding practices, and how to embed security tooling into the CI/CD pipeline. We look for candidates who can go beyond simply running a scanner to actually understanding the root cause of vulnerabilities and helping developers fix them.

Be ready to go over:

• OWASP Top 10 and beyond – Deep understanding of injection, broken authentication, SSRF, IDOR, and modern API security flaws.
• Security tooling – Practical experience integrating SAST, DAST, and SCA tools into development pipelines without slowing down engineering velocity.
• Authentication and Authorization – Mastery of OAuth 2.0, SAML, OIDC, and role-based access control (RBAC) implementations.
• Advanced concepts (less common) – Bypassing modern WAFs, exploiting complex race conditions, and cryptographic implementation flaws.

Example questions or scenarios:

• "How would you explain the impact of an Insecure Direct Object Reference (IDOR) vulnerability to a junior developer, and how would you guide them to fix it?"
• "We want to implement a new SAST tool across 50 engineering teams. How do you roll this out to ensure high adoption and low friction?"
• "Walk me through the flow of OAuth 2.0. Where are the most common security pitfalls when developers implement it?"

Cloud Security and DevSecOps

Aircall operates entirely in the cloud, meaning our infrastructure security is deeply intertwined with our product security. You will be evaluated on your ability to secure AWS environments, manage identity and access, and ensure that our infrastructure as code (IaC) is secure by default.

Be ready to go over:

• AWS Security – Deep knowledge of IAM, S3 policies, Security Groups, VPCs, and AWS-native security services.
• Container and Kubernetes Security – Securing Docker images, managing Kubernetes RBAC, and understanding container escape vectors.
• Infrastructure as Code (IaC) – Writing secure Terraform configurations and implementing automated checks for misconfigurations.
• Advanced concepts (less common) – Cloud-native incident response, advanced AWS IAM privilege escalation paths, and serverless security.

Example questions or scenarios:

• "How do you ensure that developers cannot accidentally expose an S3 bucket or an internal API to the public internet?"
• "Describe your approach to managing secrets and credentials in a highly distributed microservices environment."
• "If an alert triggers showing unusual cross-account IAM role assumption in our AWS environment, what are your immediate next steps?"

Leadership and Cross-Functional Influence

As a Staff Security Engineer, your technical skills must be matched by your ability to lead. This area evaluates how you drive consensus, mentor others, and build a security-conscious culture. Strong candidates demonstrate emotional intelligence, strategic thinking, and the ability to align security goals with business objectives.

Be ready to go over:

• Stakeholder management – Balancing product deadlines with essential security requirements.
• Mentorship – Elevating the security knowledge of the broader engineering organization through training or champion programs.
• Strategic planning – Building and executing a multi-quarter product security roadmap.
• Advanced concepts (less common) – Leading incident response communications with executive leadership or managing external bug bounty relationships.

Example questions or scenarios:

• "Tell me about a time you had to block a major product release due to a critical security issue. How did you manage the relationship with the product manager?"
• "How do you scale security knowledge across an engineering team of 200+ developers when you are the only security engineer?"
• "Describe a major security initiative you proposed, designed, and drove to completion. What was the impact?"

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