Facebook Network Engineer

DifficultymoderateRounds4

The role of a Facebook Network Engineer

The task of network engineers is to maintain high-availability network infrastructure in order to support the users' online and on-site IT activities. Network engineers work both internally within an organization and as consultants outside the organization, as well as computer network architects and security systems engineers.

Facebook is a global social networking company. Social media applications are developed by the company for people to connect via mobile devices, computers, and other devices. The application allows users to share opinions, ideas, photos, videos, and other activities online.

Role and responsibility

  • Define, document, and enforce system standards as well as configuring and installing the system to establish a networking environment
  • Design and execute new solutions, and improve the present environment's resilience
  • Manage network performance, troubleshoot problems and outages, schedule upgrades, and collaborate with network architects on network optimization
  • Use multiple sources of information to conduct data network fault investigations in local and wide area networks
  • Define and monitor access to network systems in order to ensure their security
  • Maintain firewall environments in compliance with IT security policies
  • Gather information and prioritize projects to report network operational status
  • Make sure data network equipment is up-to-date with stable firmware
  • Configure routers, switches, hosted IP voice services, and firewalls
  • Troubleshoot and resolve issues remotely if problems occur during the initial installation
  • Manage IP addresses and audit hosted devices in data centers
  • Communicate regularly with project management teams, third-line engineers, and service desk engineers
  • Contact customers via email and phone to capture initial requirements.

Skills/Qualifications required

  • Know and understand your employer's business and industry needs, as well as technical requirements
  • An understanding of the importance of customer focus and/or serving the needs of the user
  • A good communicator, particularly with nontechnical staff
  • An ability to handle a variety of tasks and pay attention to details
  • Ability to analyze and solve problems
  • A strong sense of teamwork and the ability to work with different teams, clients, and groups within an organization
  • A good sense of organization and the ability to prioritize.

Facebook Network Engineer salary

  • Entry-level salaries begin at around USD 123,588
  • Depending on your experience, you can expect to earn around USD 192,800 to USD 255,000.

Interview Guide

Facebook Network Engineer Interview process has four stages as under:

  • Recruiter Screen
  • Coding Phone Screen
  • Network Phone Screen
  • Onsite round

Recruiter Screen

Overview

It's a 30-minute telephonic interview, conducted by a recruiter/hiring manager. During the interview, you will usually be asked questions based on your resume and cover letter. In addition to being asked about your past experiences, you could also be asked behavioral questions. Communication is key in this environment.

Coding Phone Screen

Overview

It is a 45-minute telephonic interview with a Facebook network engineer. The interviewer will look to test your coding skills in programming languages such as Java, C, and Python. Live coding assessment will be done via a shared online code editor. There may also be a few theoretical questions related to fundamentals of programming.

Interview Questions

  • Write a function to draw the pattern, where the value of ‘n’ will be taken from the user, for n=4, pattern will be 1 2 3 4 5 6 7 8 9 10.
  • Write a function to find the smallest number, greater than a given number p, which does not have '11' in its binary representation.
  • What is JVM?
  • Explain inheritance and interface in Java.
  • Write a program to reverse a linked list.
  • Given an unsorted array, write a function which will accept the array and return the minimum difference between any pair.

Network Phone Screen

Overview

This is again a 45-minute telephonic interview with a Facebook network engineer. The interview will feature questions that will test your awareness and understanding of Border Gateway Protocol (BGP) and Open Shortest Path First (OSPF) concepts. You may also be asked questions on IPv6 and TCP/IP fundamentals.

Interview Questions

  • What is a carrier sense multiple access collision detect?
  • Describe how the tcp header in an IPv4 packet changes going from device to device, and which fields change within the header. Describe the same in IPv6.
  • Explain Split horizon in regards to BGP
  • How do you configure a dwdm multiplexer?

Onsite Round

Overview

The onsite round consists of 5 interviews, each about an hour long. The interview panel will consist of a Facebook software engineer, a network engineer, an HR manager, and a senior level executive. Here's a list of the 5 interviews in the onsite round:

  • 2 Networking interviews
  • Coding interview
  • System Design interview
  • Behavioural interview

Tips

  • Be thorough with networking concepts such as BGP, network architecture, TCP/IP protocols to do well in the two networking interviews.
  • Practice system design questions. Think holistically when you are given the system design problem.

Interview Questions

Most asked questions in the networking interviews:

  • Differentiate between LAN, WLAN, and MAN
  • There are 2 Vlans, named Vlan 10 and 20. Explain the process of the communication between these two Vlans.
  • Explain how a trunk port is configured between two switches?
  • Explain Load balancing for Unequal cost paths? ( Explain the scenario using the Variance method).
  • If an administrator makes any changes in the transparent mode, does it affect / advertise the change to the Switches in the network whose topology is as follows:

Sw1 (Transparent Mode) ---> Sw2 (Server Mode) ---> SW3 (Transparent mode)

  • Have you ever configured Switches, Multi layer Switches and Catalyst and Modular Switches? Tell us more.
  • What is STP and why is it used for?

Most asked questions in the Coding interview

  • Given a set of positive integers, write a function to check if it can be divided into two subsets with equal sum.
  • Write a function to find a subsequence of a given sequence in which the subsequence’s elements are first sorted in increasing order, then in decreasing order, and the subsequence is as long as possible.
  • Given a string and a dictionary of words, write a function to determine if the string can be segmented into a space-separated sequence of one or more dictionary words.

Most asked questions in the System Design interview:

  • Explain the concept of lower latency interaction?
  • Design a stock trading app
  • What do you understand by High Availability Design?
  • Design the frontend of a flower-selling e-commerce company.
  • Design a web crawler

Most asked questions in the Behavioural interview:

  • What draws you to a career in Network engineering?
  • What Facebook values appeal to you the most?
  • Tell us about an instance where you reached your goal.
  • Describe a conflict you had with a colleague.

Frequently Asked Questions

How many rounds are there in the Facebook Network engineer interview?

There are 4 rounds, namely: Recruiter Screen, Coding Phome Screen, Network Phone Screen, and Onsite ound