What Network Engineers Actually Do
Network engineering spans traditional and cloud environments.
Traditional Networking
Physical infrastructure:
- LAN/WAN design — Campus and wide-area networks
- Routing — BGP, OSPF, network path optimization
- Switching — VLAN configuration, spanning tree
- Firewalls — Network security boundaries
- Load balancing — Traffic distribution
- Wireless — WiFi infrastructure
Cloud Networking
Virtual infrastructure:
- VPC design — Cloud network architecture
- Connectivity — VPN, Direct Connect, peering
- Security groups — Cloud firewalls
- DNS — Route 53, Cloud DNS
- CDN — Content delivery networks
- Service mesh — Application networking
Network Operations
Day-to-day management:
- Monitoring — Network performance and availability
- Troubleshooting — Connectivity and performance issues
- Capacity planning — Growth and scaling
- Documentation — Network diagrams and procedures
- Automation — Configuration management, scripting
Network Engineering Specializations
| Specialization | Focus |
|---|---|
| Traditional Network Engineer | Routers, switches, physical infrastructure |
| Cloud Network Engineer | VPCs, cloud connectivity, virtual networks |
| Network Security Engineer | Firewalls, IDS/IPS, network security |
| Network Automation Engineer | Infrastructure as code, scripting |
| Wireless Engineer | WiFi, mobile networking |
Skills by Experience Level
Junior Network Engineer (0-2 years)
Capabilities:
- Basic network troubleshooting
- Configure simple network devices
- Understand TCP/IP fundamentals
- Follow established procedures
- Basic monitoring and alerting
Learning areas:
- Advanced routing protocols
- Network design
- Automation skills
- Security implementation
Mid-Level Network Engineer (2-5 years)
Capabilities:
- Design network solutions
- Implement complex configurations
- Troubleshoot advanced issues
- Automate routine tasks
- Work with cloud networking
Growing toward:
- Architecture decisions
- Large-scale design
- Specialized expertise
Senior Network Engineer (5+ years)
Capabilities:
- Architect network solutions
- Lead network projects
- Multi-site/multi-cloud design
- Evaluate new technologies
- Mentor junior engineers
Interview Focus Areas
Networking Fundamentals
Core knowledge:
- "Explain the OSI model and where common protocols fit"
- "How does TCP three-way handshake work?"
- "What happens when you type a URL in a browser?"
- "Explain the difference between routing and switching"
Routing & Switching
Protocol knowledge:
- "When would you use OSPF vs BGP?"
- "Explain VLANs and when to use them"
- "How does spanning tree prevent loops?"
- "Walk me through packet flow through a network"
Cloud Networking
Modern infrastructure:
- "Design a VPC for a three-tier application"
- "How do you connect on-premises to cloud?"
- "Explain security groups vs NACLs"
- "How would you implement multi-region networking?"
Troubleshooting
Problem-solving:
- "Users report slow network. How do you troubleshoot?"
- "A server can't reach another server. Walk me through diagnosis"
- "How do you identify network bottlenecks?"
Common Hiring Mistakes
Ignoring Cloud Evolution
Traditional network engineers may lack cloud skills. If you're cloud-first, ensure candidates understand VPCs, cloud connectivity, and infrastructure as code. Don't assume physical networking skills translate automatically.
Expecting Only Cloud
Cloud network engineers may struggle with physical infrastructure. If you have data centers or complex physical networks, evaluate traditional skills alongside cloud experience.
Undervaluing Automation
Modern network engineering requires automation. Engineers who can only configure manually will struggle with scale. Python, Ansible, and infrastructure as code are increasingly important.
Over-Specifying Vendor Experience
Cisco vs Juniper vs Arista matters less than understanding concepts. Strong network engineers learn new vendors quickly. Don't eliminate candidates for vendor-specific gaps.
Recruiter's Cheat Sheet
Resume Green Flags
- Mix of traditional and cloud networking
- Automation experience (Python, Ansible)
- Specific protocol expertise
- Troubleshooting examples
- Certifications (CCNA, AWS networking)
- Network design experience
Resume Yellow Flags
- Only traditional or only cloud
- No automation skills
- Cannot explain protocols used
- Only monitoring, no implementation
Technical Terms to Know
| Term | What It Means |
|---|---|
| TCP/IP | Core internet protocols |
| BGP | Routing protocol between networks |
| VPC | Virtual Private Cloud network |
| VLAN | Virtual LAN segmentation |
| SDN | Software Defined Networking |
| DNS | Domain Name System |
| Load Balancer | Distributes traffic across servers |
| VPN | Encrypted network tunnel |
Where to Find Network Engineers
Top network engineers are found at ISPs, data center operators, cloud providers like AWS and Google, and enterprises with complex infrastructure. Professional communities like NANOG, Cisco DevNet, and local network engineering meetups are excellent sources. Certifications like CCNA/CCNP holders often congregate on Reddit's r/networking and tech-focused Discord servers.