Network engineer

A network engineer designs, deploys or operates the networks that connect an organisation’s sites, equipment and services. They turn connectivity needs into technical choices, then help maintain the availability and security of communications. The balance between design and support varies by role: spelling it out prevents hiring against a title that is broader than the actual responsibilities.

The work may begin with analysing how the network will be used and writing specifications. The engineer then selects or justifies a topology, capacity, connectivity solutions and network security measures. On a deployment project, they may configure equipment, organise tests and coordinate those involved. In operations, they monitor performance, investigate the cause of an incident, fix the problem and keep documentation up to date. One role may combine these activities, or they may be divided among several specialists.

The network may be physical or virtual, local or wide area, wired or wireless. Connectivity to cloud services falls within the role when a hybrid architecture or virtual network calls for it. The presence of cloud services in the organisation does not, by itself, require expertise in a particular provider. Likewise, a network engineer may configure access controls or help secure communications without bearing sole responsibility for the entire cybersecurity policy.

Network engineer, systems and network administrator, and cloud architect: who does what?

• Network engineer: the role may combine network design, deployment and incident resolution. Its authority over architectural choices should be made explicit.
• Systems and network administrator: the remit may also include systems. Monitoring and configuration tasks overlap with those of a network engineer; the title alone does not distinguish the profiles.
• Cloud architect: if the need concerns a connection to a virtual network, define which connectivity decisions belong to the network engineer and which fall under cloud architecture.

Reporting lines and the division of decisions depend on the organisation. When defining the role, state who sets network standards, who approves an architectural change and who responds when an incident affects several environments.

Hiring a network engineer should start with a specific need: creating connectivity, changing existing infrastructure or handling incidents more effectively. The level of expertise required depends on that priority. An organisation expecting architectural decisions needs someone who can relate user needs to capacity, availability and security parameters. If it mainly needs day-to-day operations, diagnosis, configuration and documentation carry more weight.

A poorly defined remit can leave decisions without an owner. Asking one person to define the architecture, provide local support and make every cybersecurity decision blurs the hiring criteria. Conversely, restricting the search to familiarity with one equipment brand can obscure the ability to reason about topology or isolate a fault. The existing equipment matters, but it should be linked to the duties actually assigned.

Illustrative case: a company connects another site to its network and experiences interruptions after deployment. If the need centres on design, assess capacity planning, connectivity paths and validation tests. If it centres on operations, assess the available measurements, the diagnostic method and how the fix would be documented.

Network security also needs a defined remit. Access controls, authentication and protecting communications may be part of network work. The organisation should nevertheless clarify who sets the rules, who applies them to equipment and who decides when availability conflicts with restricted access. This division helps assess the expected autonomy and cooperation with other specialists.

Finally, the environment shapes the role’s constraints: local or wide area networks, remote sites, virtual services and coordination of providers. Describe the incidents to be handled and the authority to change a configuration. Any requirement to be available outside normal hours should follow from the arrangements for service continuity and the applicable framework, rather than be assumed for all network engineers.

• Analyse user needs and turn them into network connectivity specifications.
• Design a topology and justify choices about capacity, availability and security.
• Configure network equipment and routing functions in line with the agreed specifications.
• Prepare tests and validate a network change before it goes live.
• Coordinate the technicians or providers involved in a network deployment.
• Monitor performance and identify network anomalies.
• Diagnose incidents, apply a fix and document their cause.
• Maintain the diagrams, configurations and procedures needed for operations.

A scientific course of study, a French BUT degree, a French licence degree or French preparatory classes can lead to engineering studies in telecommunications and networks. The Cnam also illustrates a continuing education route for working professionals. These are possible routes into the profession; the responsibilities a person has held then determine their fit for a role.

A focus on design calls for needs analysis, writing specifications and choosing a topology or network capacity. Depending on the role, the engineer may apply an established architecture, design a component within a defined framework or take responsibility for major network decisions. A focus on operations calls for configuration, monitoring, incident diagnosis and documenting interventions. Routing, wireless access points or virtual connectivity may also be useful, depending on the infrastructure.

Training provides technical foundations that experience can deepen in either direction. When changes affect several services or providers, coordination is also a useful acquired skill. A qualification and length of experience alone do not establish a person’s autonomy in the assigned tasks.

To assess this profile, link each stage to the networks your organisation needs to design or operate. A criteria grid and references can support the decision.

1. Set the criteria before the interview

Build a criteria grid linked to the role’s tasks. Distinguish what can be checked in the application from what needs to be explored in an interview, and set out how to check each criterion. Then separate design, deployment and operations responsibilities. For each, note the expected outcome and necessary autonomy. Someone applying an approved design need not demonstrate the same level of decision-making as someone choosing the topology and capacity parameters. Prioritise skills according to your infrastructure: routing, wireless networking, monitoring, access controls or cloud interconnection. Identify what can be learnt after starting the role. Link each criterion to a real task and state the expected use of any products mentioned.

2. Examine past work

Ask the candidate to choose a network change they helped make. Have them explain the initial need, specifications, technical choices and their part in the decisions. An anonymised diagram or procedure may help clarify their contribution. For an operations profile, ask instead how an incident was detected, which indicators they consulted and what was documented after the fix. Their explanation distinguishes work they did themselves from work they only observed. If they cannot describe the constraints or tests, check the true extent of their role.

3. Present a case close to the role

Present a simplified network, symptoms and a few performance measurements. Ask the candidate to put forward hypotheses, choose checks and explain what would lead them to revise their diagnosis. If the role includes design, also ask how they would relate capacity and availability needs to a topology. This lets you observe their reasoning without requiring an answer tied to a vendor absent from your environment. Explaining trade-offs and limits is a positive sign; proposing a configuration change without first checking is a warning sign.

4. Observe communication and coordination

Ask how the candidate would tell users about an incident and then organise an intervention by technicians or providers. Listen for whether they distinguish established facts, hypotheses and decisions that need approval. For a cross-functional role, also explore how they would work with systems, cloud and security teams where their responsibilities overlap. A useful answer identifies the people involved and the decision at issue. Be wary of an answer that gives the network engineer sole responsibility for every cybersecurity decision.

5. Check references and reach a decision

With the candidate’s consent, take professional references to clarify criteria still to be checked. Ask for concrete examples from the context in which they worked together. For this role, ask in particular what types of incidents or deployments were assigned to the candidate and how much autonomy they had. Compare these accounts with the work described and the criteria set at the outset. If your team lacks sufficient network expertise, ask a specialist who can explain their criteria to assess the diagram or practical case. The final decision should rest on the role’s remit and observed abilities, rather than familiarity with a piece of equipment alone.