20 Automotive Cybersecurity (ISO 21434) Interview Questions for EV Engineers

Connected EVs are a target-rich attack surface. ISO 21434 (the automotive cybersecurity engineering standard) is now mandatory for new vehicle programmes under UNECE R155. Cybersecurity engineers + architects are in heavy demand and the interview bar has risen quickly.

Standards + lifecycle

• Walk through the ISO 21434 lifecycle phases.
• What's the relationship between ISO 21434, UNECE R155 + R156?
• Define TARA (Threat Analysis + Risk Assessment) and walk through the steps.
• What's a Cybersecurity Assurance Level (CAL) and how is it derived?

Architecture + hardware

• Walk through secure-boot for an EV ECU. Cover root-of-trust + signature verification + rollback prevention.
• What's the role of a Hardware Security Module (HSM) like Infineon SHE or AURIX HSM?
• Walk through key-storage + key-rotation for a 10-year vehicle lifecycle.
• Explain the zonal vs domain vs central-compute architecture cybersecurity trade-offs.

OTA + connectivity

• Walk through a secure OTA-update flow. Cover authentication + integrity + atomic update + rollback.
• What's the difference between TLS termination at the gateway vs at each ECU?
• Walk through V2X PKI architecture for ETSI / SCMS deployments.
• How do you handle SOTA (software-over-the-air) vs FOTA (firmware-over-the-air) differently?

Threat modelling + incident response

• Walk through a TARA on the charging-port communication interface.
• What attack vectors target charging-network roaming + payment flows?
• How do you detect a CAN-bus intrusion on a moving vehicle?
• Walk through the cybersecurity incident-response process for a deployed fleet.

Behavioural + organisational

• How do you push security requirements into a team that's behind on schedule?
• Describe a time you found a vulnerability in an existing system.
• How do you coordinate cybersecurity with functional-safety (ISO 26262)?
• What's the most underestimated cybersecurity risk in Indian EV today?

Where to go from here

Automotive cybersecurity interviews test breadth across standards + architecture + cryptography + incident-response + organisational soft skills. Prepare specific scenarios + named-product references (Infineon AURIX, Cypress secure boot, ARM TrustZone, GlobalPlatform). The candidates who win interviews demonstrate both the technical depth and the organisational pragmatism that gets security work done in real product teams.

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