When interviewing sysadmin candidates, focus on three pillars: technical expertise, problem-solving approach, and cultural fit. The modern sysadmin role blends traditional system administration with DevOps practices, requiring knowledge across multiple domains.

Start with fundamental questions that reveal the candidate's system architecture understanding:

# Example technical questions:
1. "Walk me through troubleshooting a sudden 500% CPU spike on production servers"
2. "How would you secure SSH access across 200 servers?"
3. "Explain your process for zero-downtime deployments"

Look for answers demonstrating methodical thinking. Strong candidates will mention:

• Monitoring tools (Prometheus, Nagios)
• Log analysis (ELK stack, journalctl)
• Configuration management (Ansible playbooks)

Present real-world scenarios like:

# Sample scenario
"At 3 AM, the on-call engineer receives alerts about failing database 
connections. The application is throwing 'too many connections' errors. 
Walk me through your diagnostic process and resolution steps."

Evaluate their approach to:

• Impact assessment (checking dashboards first)
• Triage methodology (connection pooling vs. queries analysis)
• Communication plan (status pages, stakeholder updates)

Modern sysadmins should demonstrate IaC proficiency. Present a Terraform challenge:

# Requested solution example
resource "aws_instance" "web" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"
  
  tags = {
    Name = "InterviewWebServer"
  }
  
  user_data = <<-EOF
              #!/bin/bash
              yum install -y nginx
              systemctl start nginx
              EOF
}

Conduct a tabletop exercise simulating a security breach:

# Incident timeline example
1. Unusual outbound traffic detected
2. Unauthorized AWS IAM role created
3. Cryptominer process running on multiple nodes

Assess their containment strategy, forensic approach, and post-mortem process.

Technical skills alone aren't sufficient. Include questions about:

• Documentation practices (Runbooks, Wiki standards)
• Mentoring junior team members
• Handling priority conflicts between teams

Admin scripting is crucial. Provide a Python challenge:

# Sample problem: Parse server logs
import re
from collections import defaultdict

def analyze_logs(logfile):
    error_counts = defaultdict(int)
    ip_pattern = r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}'
    
    with open(logfile) as f:
        for line in f:
            if 'ERROR' in line:
                ip = re.search(ip_pattern, line)
                if ip:
                    error_counts[ip.group()] += 1
                    
    return dict(error_counts)

Assess alignment with your team's values through questions like:

• "Describe your ideal post-incident review process"
• "How do you stay current with emerging technologies?"
• "Share an example of improving an existing process"

---

When interviewing sysadmin candidates, focus on practical demonstrations rather than theoretical knowledge. Create a lab environment (or use containers) where candidates can:

# Example troubleshooting scenario you might provide
#!/bin/bash
# Server throwing 500 errors - diagnose
LOG_FILE="/var/log/nginx/error.log"
if [[ ! -f "$LOG_FILE" ]]; then
    echo "Error: Log file missing. Checking alternatives..."
    journalctl -u nginx --no-pager | grep -i error
else
    tail -n 50 "$LOG_FILE" | grep -A5 -B5 "500"
fi

Present problems requiring automation solutions. For example:

# Sample task: Write a script to monitor disk space
#!/bin/bash
THRESHOLD=90
ALERT_EMAIL="admin@company.com"

df -h | awk -v threshold=$THRESHOLD '
    NR>1 {
        gsub(/%/,"",$5);
        if ($5 > threshold) {
            print "ALERT: "$6" is at "$5"% usage"
            # Add email alert logic here
        }
    }'

Describe a broken network situation and ask for troubleshooting steps:

# Example correct approach you'd want to see
ping 8.8.8.8 # Check basic connectivity
traceroute example.com # Identify routing issues
nslookup example.com # Check DNS resolution
netstat -tuln # Check local services
tcpdump -i eth0 port 80 # Packet capture

Ask about implementing secure configurations:

# Example SSH hardening they should know
Port 2222
PermitRootLogin no
MaxAuthTries 3
LoginGraceTime 1m
AllowUsers admin_user deploy_user

Even for on-prem roles, cloud knowledge is essential:

# AWS CLI example they might need to write
aws ec2 describe-instances \
  --query 'Reservations[*].Instances[*].[InstanceId,State.Name,PublicIpAddress]' \
  --output table

Present collaboration scenarios like:

# Ask how they'd handle this CI/CD pipeline failure
#!/bin/bash
# Failed deployment rollback process
if [[ "$DEPLOY_STATUS" != "success" ]]; then
    git reset --hard $LAST_GOOD_COMMIT
    docker-compose down && docker-compose up -d
    send_slack_alert "Rollback executed for $SERVICE_NAME"
fi

Always follow technical questions with "why" probes to understand their reasoning process behind solutions. Combine whiteboard design sessions with hands-on terminal work for comprehensive evaluation.