Preparing for an interview at Johnson Controls requires a balanced approach. You must demonstrate deep technical competency while showing that you can communicate complex engineering concepts to non-technical stakeholders.

Role-Related Knowledge – You must master the fundamentals of your specific track. For hardware-centric roles, review digital electronics, control systems, and basic electrical engineering. For cybersecurity-centric roles, focus on network protocols, cryptography, and OT/ICS security frameworks.

Problem-Solving Ability – Interviewers want to see how you structure your thoughts. When presented with a complex system failure or security vulnerability, break the problem down systematically and explain your reasoning out loud.

Leadership & Value Alignment – Johnson Controls highly values integrity, customer focus, and safety. Be prepared to share stories that demonstrate how you take ownership of projects and prioritize the safety and security of the end user.

Collaboration & Teamwork – Because security systems touch multiple departments, you must prove you can work across disciplines. Expect questions that test your ability to bridge the gap between software developers, field technicians, and project managers.

The interview process for a Security Engineer at Johnson Controls is structured to evaluate both your technical depth and your cultural fit. Depending on the seniority of the role and the location, the process typically spans three to four distinct stages.

The journey begins with an initial screening, which may be a quick conversational phone call with a recruiter or a short 10-to-15-minute Teams meeting with the hiring manager. This initial touchpoint is designed to assess your interest, verify your basic qualifications, and ensure you understand the company's core mission. For campus recruitment or entry-level positions, this stage may also include an online technical and aptitude test consisting of rapid-fire questions covering basic electronics, control systems, and quantitative reasoning.

If you pass the initial screen, you will move into the core technical evaluation phase. This often involves a panel or "board" interview where you will present your past projects and answer deep-dive technical questions. In some locations and teams, you may also participate in a group interview or collaborative exercise designed to evaluate how you communicate, share ideas, and work with others to solve complex engineering problems.

This visual timeline illustrates the typical progression from your first contact to the final decision. Candidates should use this roadmap to pace their preparation, focusing first on high-level company research and basic technical fundamentals, before diving deep into system design and behavioral scenarios for the panel and board stages.

To succeed at Johnson Controls, you must perform well across several distinct evaluation areas. Understanding what interviewers look for in each area will help you tailor your preparation.

Hardware, Electronics & OT Systems

For roles involved in physical security systems and building automation, a strong grasp of electronics and operational technology is mandatory. Interviewers want to know you can design and troubleshoot the physical components of a security network.

Be ready to go over:

• Control System Theory – Feedback loops, open vs. closed systems, and system stability.
• Digital Electronics – Logic gates, microcontrollers, and signal processing.
• Hardware Integration – Connecting sensors, relays, card readers, and IP cameras to centralized controllers.
• Advanced concepts (less common) – Modbus/BACnet protocols, PLC programming, and electrical load calculations for security panels.

Example scenarios:

• "Explain how you would troubleshoot a communication failure between an access control panel and an electromagnetic door lock."
• "How would you design a backup power system for a security hub that must remain operational for 24 hours during a blackout?"

Cybersecurity & Network Architecture

With the rise of smart buildings, securing the networks that control physical infrastructure is paramount. You will be evaluated on your ability to protect systems from unauthorized access and cyber threats.

Be ready to go over:

• Network Segmentation – Designing VLANs and firewalls to isolate OT networks from IT networks.
• Secure Protocols – Implementing HTTPS, SSH, TLS, and 802.1X in device communications.
• Vulnerability Management – Identifying, assessing, and patching firmware vulnerabilities in edge devices.
• Advanced concepts (less common) – Threat modeling for smart building ecosystems and implementing Zero Trust architectures in OT environments.

Example scenarios:

• "How would you secure a network of 500 IP security cameras distributed across a campus against unauthorized access?"
• "Walk me through how you would configure a firewall to allow secure remote maintenance of a building's access control system."

Collaborative Problem-Solving & Group Dynamics

Johnson Controls frequently uses group interviews or panel presentations to see how you perform in a team setting. They are looking for engineers who can advocate for secure designs without alienating teammates.

Be ready to go over:

• Active Listening – Showing respect for other candidates' or team members' ideas during group exercises.
• Constructive Feedback – Challenging technical assumptions politely and productively.
• Clear Communication – Translating complex technical risks into business impacts.

Example scenarios:

• "During a group system-design exercise, another engineer proposes a solution that compromises network security for lower cost. How do you handle this?"
• "Describe a time you had to convince a client or project manager to adopt a more secure but expensive engineering design."