At Plexus, a Systems Engineer plays a critical role in designing, implementing, and maintaining the robust technology infrastructure that powers global product design and manufacturing services. Because Plexus partners with leading brands across highly regulated industries—such as healthcare, life sciences, aerospace, and defense—the reliability, security, and scalability of its internal systems are paramount. As a Systems Engineer, you are not just managing servers; you are directly enabling the engineering and manufacturing teams to deliver life-saving and mission-critical products to the market.

This role requires a unique blend of traditional on-premises systems administration and modern cloud integration. You will have a direct impact on optimizing network infrastructure, securing hybrid Active Directory environments, and scaling cloud operations in Microsoft Azure. Working out of major hubs like Neenah, WI or supporting global operations, you will tackle complex system challenges that demand high availability, strict compliance, and seamless cross-functional collaboration.

The position is both intellectually challenging and highly rewarding, offering the chance to work with cutting-edge enterprise tools. Successful candidates at Plexus thrive on solving complex technical puzzles, collaborating with multidisciplinary teams, and demonstrating a strong passion for continuous learning and technological evolution.

The interview process at Plexus evaluates both your technical depth and your alignment with the company's collaborative culture. The following questions are representative of what you can expect, compiled from real candidate experiences across various seniority levels. They are grouped by core competency to help you structure your preparation.

Active Directory & Windows Server Administration

This category evaluates your core systems administration skills, focusing on the Microsoft ecosystem which forms the backbone of the Plexus corporate infrastructure.

• How do you troubleshoot a Group Policy Object (GPO) that is failing to apply to a specific subset of organizational units (OUs)?
• Explain the difference between Active Directory (AD) replication topologies and how you would diagnose a replication delay.

Preparing for an interview at Plexus requires a balanced approach. You must demonstrate deep technical competency while remaining highly approachable, collaborative, and communicative. The hiring team looks for well-rounded engineers who can translate technical complexity into business value.

Role-Related Knowledge – You must possess a strong grasp of the Microsoft ecosystem, virtualization, networking, and cloud technologies. Be ready to discuss real-world deployment, configuration, and troubleshooting scenarios rather than just theoretical concepts.

Problem-Solving & Presentation Ability – For mid-to-senior roles, your ability to structure complex problems and present solutions to a technical audience is heavily scrutinized. You will need to show that you can think systematically, evaluate trade-offs, and defend your architectural choices under questioning.

Collaboration & Communication – Because Systems Engineers interact with diverse teams—including software developers, project managers, and manufacturing plant IT personnel—clear and empathetic communication is essential. You must demonstrate that you are a supportive teammate who values collective success over individual recognition.

Continuous Learning & Passion – Plexus values engineers who are genuinely curious and proactive about their professional growth. Sharing your personal labs, open-source contributions, or self-driven learning paths can set you apart from other candidates.

The interview process at Plexus is designed to evaluate both your technical capabilities and your alignment with company culture. It typically begins with a casual screening call and culminates in a rigorous, interactive technical review.

The initial phase focuses on understanding your background, career goals, and fundamental technical knowledge. If you pass this stage, you will move into a deeper technical assessment. For advanced or senior roles, this includes an on-site presentation where you will present a technical topic or past project to a panel of engineers and managers.

The timeline above outlines the typical progression from the initial application to the final decision. Candidates should use this timeline to pace their preparation, ensuring they have thoroughly polished their technical presentation well before the on-site loop. While the process is comprehensive, be prepared for potential communication delays, as scheduling coordinates multiple senior team members.

To succeed at Plexus, you need to understand the key areas where the technical team will focus their evaluation. Expect your interviewers to drill deep into these domains.

Microsoft Ecosystem & Active Directory

Active Directory and Windows Server management are core to the Systems Engineer role at Plexus. Interviewers will evaluate your ability to manage, secure, and scale these environments.

Be ready to go over:

• Group Policy Management – Designing, inheritance, filtering, and troubleshooting GPOs at scale.
• Identity & Access Management – Managing user lifecycles, role-based access control (RBAC), and directory services security.
• PowerShell Automation – Scripting for bulk administration, monitoring, and automated provisioning.
• Advanced concepts (less common) – Active Directory Federation Services (ADFS), multi-forest trusts, and disaster recovery planning for domain controllers.

Example questions or scenarios:

• "A user reports that a newly deployed software package is missing from their machine. How do you verify if the GPO targeted at their OU is applying correctly?"
• "Describe how you would design an Active Directory structure for a newly acquired business unit with 500 users."

Cloud Infrastructure & Azure Integration

As Plexus continues its cloud journey, demonstrating proficiency in hybrid cloud architectures and Microsoft Azure is vital.

Be ready to go over:

• Hybrid Identity – Azure AD Connect, single sign-on (SSO), and multi-factor authentication (MFA).
• Cloud Resource Management – Provisioning virtual machines, configuring virtual networks (VNets), and managing storage accounts.
• Cost Optimization – Utilizing Azure Advisor, managing reservations, and sizing resources appropriately.
• Advanced concepts (less common) – Infrastructure as Code (IaC) using Terraform or ARM templates, and Azure DevOps pipelines.

Example questions or scenarios:

• "How would you design a highly available application architecture in Azure that spans multiple regions?"
• "What security measures would you implement to protect a public-facing web server hosted in Azure?"

Network & Infrastructure Fundamentals

A solid grasp of networking ensures you can support complex manufacturing and corporate environments without relying solely on the dedicated network team.

Be ready to go over:

• Core Protocols – Deep understanding of TCP/IP, DNS, DHCP, and HTTP/S.
• Network Security – Firewalls, network security groups (NSGs), VPNs, and secure remote access.
• Performance Diagnostics – Using tools like Wireshark, traceroute, and ping to isolate network bottlenecks.

Example questions or scenarios:

• "An application server in our DMZ cannot communicate with an internal database. Walk us through your troubleshooting steps."
• "Explain how DNS routing works when a user attempts to access an internal intranet site from a remote VPN connection."

Technical Presentation & Communication

For senior positions, the on-site presentation is the most critical hurdle. You will present to a panel of 5-6 technical team members.

Be ready to go over:

• System Architecture Design – Presenting a complex system you designed or migrated, explaining the "why" behind your technical choices.
• Handling Q&A – Defending your design choices calmly and constructively under technical scrutiny from the panel.
• Presentation Skills – Structuring a clear, engaging slide deck and managing your time effectively.

Example questions or scenarios:

• "Why did you choose that specific backup strategy over a multi-region replication model in your project?"
• "How did you manage stakeholder expectations when this migration project faced unexpected downtime?"