Facebook Interview Questions

Facebook is the first acronym of FAANG companies. Known for its unique culture and supremely structured processes, Facebook is the technology world's undisputed king. If you are looking ahead to interviewing at Facebook, this article can open up many insights into the process and type of questions you can expect at the interview. 

The job and life at this tech giant are exceptionally rewarding but does not come easily. You will need to work hard and brush up all your skills to go through and crack the intensive rounds to reach the next stage. 

The interview process at Facebook is quite elaborate, and there is no stage you can take lightly right from the beginning. Here are some insights into the interview process at Facebook.

Preparing for Facebook Interview

Facebook is among the world's most technologically advanced companies with great scope for growth ahead. Preparing for the Facebook interview is not a tough nut to crack but requires dedication and exceptional expertise in your domain and language. There is no bar in terms of experience for a prospective candidate at Facebook. The only and most important requirement is expertise in programming and designing. 

One thing that you must keep in mind while sitting for any technical interview is that you must choose a preferred programming language that you can claim expertise in. You can mention multiple languages you feel comfortable working in but there must be one language you must select to pursue your interview with. This will help you in narrowing down the curriculum you have to read through to prepare for. Most mainstream languages like Java, C++, C, Python and JavaScript, along with several others are accepted at Facebook. 

Facebook Technical Interview Questions

As it is apparent from the structure of interviews, coding, and programming is the essence of the complete process accompanied by a great cultural fit. Coming to the technical part, Facebook focuses a lot on the basics and fundamentals of programming and its elements. 

You can find a majority of questions from four primary categories:

1. Algorithms
2. System Design
3. Product Design
4. Data Structures

Below are some questions that you can expect to be asked at your interview with Facebook. As discussed above, the questions predominantly cover the language you have mentioned expertise in but you can also find a fair mix of fundamentals questions as well. 

Facebook Interview Questions Based on Data Structures and Algorithms

The data types under which data is arranged in computer memory are called Data Structures. Following are the main categories of Data Structures;

1. Array
2. Linked list
3. Doubly linked list
4. Binary tree
5. Binary search tree
6. Graphs
7. Matrix
8. Stack 
9. Queue
10. Heap 
11. Hashing
12. Advanced data structure

The questions generally are a mix from these categories and will not be asked in a straightforward manner. You will be expected to look at the bigger or hidden picture and then approach the problem in a holistic manner. 

Here are commonly asked Data Structure and Algorithm questions at Netflix interviews;

1. Write a code to detect a loop in a linked list.
2. Without recursion, traverse a binary tree in Post order. 
3. Use stack to find the sum of two linked lists.
4. Write a code to find out the duplicate in an integer array of 1 to 1000 numbers. 
5. How will you add two numbers represented by linked lists.
6. Write a code to check if in a given linked list there exists a cycle? Explain the process how to find the starting node of it.
7. Write a code to count the distinct absolute values in a given sorted array.
8. Write a code to reverse the words in a given sentence without using any library method.
9. How will you detect and remove loop in a linked list.
10. State the Boolean Parenthesization Problem?
11. Write a code to remove duplicate nodes?
12. Write a code to check if the given string is a palindrome. 
13. Write a code to find out the largest and the smallest number, for a given integer array.
14. Write a code to conduct sorting using the quicksort algorithm, for a given integer array.
15. How will you print all the leaves of a given binary tree? 
16. Write a code to remove any duplicates in a given array without the use of any library?
17. For a given integer array, find all the pairs whose product is equal to a given number. 
18. How will you find a missing number in a given integer array of numbers 1 to 100?
19. How will you implement a radix sort algorithm?
20. How will you implement a bubble sort algorithm? 
21. Swap two numbers without making use of any third variable.

Facebook Interview Questions Based on Systems Design

The Systems design role is one of the most crucial roles at Facebook. Being an interactive platform, the system needs to be robust, dynamic and flexible all at the same time. It needs highly focused professionals who understand the system requirements and can make the best out of what is available. 

Here are some systems design questions you can expect at your Netflix interview;

1. If asked, how will you redesign the Instagram Newsfeed? Share your ideas about the kind of algorithm you will use. 
2. How will you design a universal file sharing and storage app similar to Dropbox or Google Drive?
3. If you were to design a web crawler, what all will you list in the requirements and pre-requisites?
4. What kind of application is Airbnb and justify why it should the way it is? 
5. Can you design an API rate limiter?
6. How important are the requirements determination at any phase of the project?
7. What types of documentation have you worked upon in system design? What is the right stage to prepare documentation? Is there any thumb rule?
8. Suppose we have a large URL for a given page, how will you shorten it?
9. What are the main concerns in designing social media platforms like Facebook or Instagram?
10. What are the major challenges in designing apps like Quora that are both a social media platform and a message board service?
11. Can you design a proximity server? 

Facebook Behavioral Interview Questions

Though each and every phase of the interview at Facebook is inclined towards accessing the programming skills of a potential candidate, the behavioral aspect holds equal importance too. Recruiters keep a keen eye on your body language, your social and professional adaptability, learning ability, and other skills, to name a few. 

Facebook is very specific and certain about its 5 core values. The recruiters give a go-ahead only to the people who are culturally fit and flexible enough to accommodate some personality changes in them. 

The skillset varies from role to role but the five core values are a must have in everyone who wishes to work at Facebook. If you have applied for a senior role, be prepared to answer questions based on but not limited to team handling, leadership, ownership, delegation, hierarchy etc. 

If you have applied for a beginner to mid level role, the questions will revolve around but not limited to receiving feedback, team working, mutual output, collaborations, hierarchy, time management and query handling. 

Here are some behavioral questions to expect at your upcoming Facebook interview;

Questions Based on Teamwork and Collaboration

Teamwork is foundational to every organization. No successful organization can work without cohesive teams that work together and towards a common goal. Among all the FAANG companies, Facebook is famous for its cross-functional teams and tasks that require every individual to be extra flexible and adaptable as per situation and requirement. 

Here are some teamwork and collaboration based questions asked at Facebook interviews;

1. How highly do you rate teamwork on a scale of 10?
2. Would you rather prefer working independently? (Do not answer this question in a Yes unless you have an undeniably rocking explanation to it)
3. Have you ever been into a challenging team situation? What did you do to move towards a resolution? 
4. How did you motivate your team? Was it effective?
5. If hired, what will be your contribution to our team culture?
6. How can you check the effectiveness of measures you take as a team lead?
7. What if for some time you work in an individual setup and later the company decides to move into a teamwork setup?
8. How good are you at taking and accepting failure?
9. Have you ever dealt with a team mate who eats up everyone credit? What did you do about it?
10. How good are your relations with your previous project team members? What if we want to talk to them?

Questions on Work-Life Balance and Handling Work Related Stress

Here are some work life balance questions Facebook recruiters can ask you;

1. Are you comfortable in working 7 days a week and stay till late in the office?
2. Describe your typical workday?
3. How seriously do you take hobbies and interests?
4. Did you ever leave a job because of a tough boss? 
5. How well do you take criticism? What will you do if you get criticised in front of your team?

Questions Based on Client Management Skills

Client management is an important aspect skill to have at Facebook. Irrespective of your role, you would be dealing with some clients within or outside the company. Given the fast pace and dynamically changing environment, managing all your clients will be one thing you need to ace as soon as possible.  

Here are some client management skills related questions you can expect;

1. What is your typical strategy while approaching and dealing with clients? Do you follow the same approach for all?
2. How do you prioritize your clients? What if you are required to deal with multiple clients on a day-today basis?
3. How will you justify a decision that cost you a valuable client?
4. List out the main trigger points that indicate the company CRM needs to be revamped?
5. How do you gain the trust of your clients? 
6. Do you have any testimonials from your previous clients?
7. What is your take on the latest market trends?

Questions Based on Relationship with Manager and Supervisor

Here are some questions based on relationship with manager asked at Facebook interviews 

1. Describe your boss in 1 line.
2. Who is an ideal boss in your eyes?
3. What was the biggest criticism you received from your boss? What did you do about it?
4. What if your boss is making a wrong decision regarding a client you know well about? How will you deal with this situation?

Questions Based on Adaptability

Here are some adaptability-related questions you may find helpful;

1. The culture of Facebook is quite different from your last organization. How are you planning to get settled?
2. How hungry are you for control? How do you react to situations you have no control over?
3. How will you accommodate sudden and abrupt last-minute changes from the client-side?
4. What strategy will you adopt to implement new technology or process within your team? 
5. How will you deal with resistance from your team on change?
6. What if one of the teammates follows inefficient practices? Have you ever compromised in such situations? What is your take on the same?

Questions Based on Facebook- Products and Company

1. What is your take on Facebook acquiring Instagram?
2. Are you sure you want to work at Faceook? Why?
3. What is your take on Facebook advertising?

Facebook Interview Questions Based on Past Projects

Past projects help recruiters understand the level of exposure you have had in your previous roles.   Recruiters at Facebook focus on learnings, challenges, and growth you have had in your past roles and projects. 

Here are some questions;

1. Were you ever part of a project you did not want to take up? If yes, how did you keep up your motivation levels?
2. What factors make working on a project tough?
3. How do you react to failure? Did you ever fail in any of your past projects?

Java Interview Questions Asked at Facebook Interviews

Java is among the most preferred languages at FAANG companies. Having expertise in Java can help you get the extra edge over other candidates while interviewing at most tech companies.  Here are some Java-based questions you can expect at your Facebook interview;

1. What are multiple inheritances? Can you do that in java? Give reason for your answer
2. Where do you declare Wait and Notify?  Give reason for your answer
3. What do you mean by string immutable?
4. How are passwords stored in Java? Is there any specific reason for it?
5. What do you mean by operator overloading? How does Java environment react to it?
6. What do you mean by Maps in Java? List all of them
7. List the number of ways you can handle exceptions in Java?

Python Interview Questions Asked at Facebook Interviews

1. Explain pickling and Unpickling. 
2. What do you mean by a dynamically typed language?
3. What is PEP8? What is its importance?
4. What do you mean by decorators in python?
5. Write a code to copy an object in python.
6. What do you mean by _init_ in python?
   

SQL Questions Asked at Facebook Interviews

1. Construct a SQL query to find the second highest age of students.
2. What do you mean by joins in SQL?
3. Write a SQL query to find out the maximum and minimum salary of employees in a company.
4. What is the full form of ACID?
5. Write a SQL query to find the count of employees working under project T2.
6. Write a SQL query to delete the duplicate rows in a database. 
7. Write a SQL query to find the current time and date.

Categorisation of Facebook Interview Rounds

The complete interview process at Facebook is categorised into two stages. Here is detailing of the stages:

Stage 1: Initial Technical Screen

This stage comprises four rounds that help the interviewer gauge your initial technical soundness along with what are your aspirations from the company and this role. The rounds are:

1. Introduction
2. Unfolding Career Aspirations
3. Coding related questions and tasks
4. General and technical questions

Though this round is named as the initial screening round, the recruiters at Facebook take it very seriously and expect the same from candidates. Even the initial questions on products, product life cycle, a challenging scenario, ideal use case or some personalised growth hack etc. Preparing for this stage requires a lot of homework and research to be done on Facebook as an evolving enterprise. 

This interview typically begins by the interviewers introducing themselves and giving a fair idea about what is done at Facebook and how. The panelists also deeply focus on judging your seriousness as a professional and gauge you for your vision and enthusiasm to join the company. 

Once through the behavioral stuff, a majority of the time will be spent on a shared coding editor platform. The panelists assign problems and tasks that are short and doable within 20 to 30 minutes. The agenda behind this task is not limited to examining candidates' coding skills but also what approach do they take to solve the problem. The last few minutes of stage 1 are spared for the candidate to ask questions about Facebook, the culture, the working style, expectations, how they approach a problem etc. Basically, the tables turn, and the candidates can ask whatever they want to know about the company, employees, work, and culture. 

Preparation Tip: Do not take this stage lightly. Right from the introduction to the type of questions you ask the panelists, you will be gauged for every single word you say, write and code. 

Make sure you practice the coding questions both by hand and on a simple text editor. In most cases, virtual interviews were conducted for stage 1, and the panelists used platforms and environments similar to a simple text editor for coding related questions. 

Re-run through all the algorithms and coding fundamentals before you sit for the interview. 

Learn to manage your time across all the problems given to you. Practice with a timer and stay true with the limits and deadlines while preparing. 

Keep your fundamentals strong. Even if you are an experienced coder, programmer, or engineer, there is a high possibility that your day to day activities and work does not involve fundamental elements of programming. Brush up your concepts on data structures, lists, arrays, heaps, trees. Also, side by side, make sure you run through the algorithms, sorting techniques, approaches, and theories. 

For the coding related questions, try to involve the interviewer by speaking what you are thinking. This will help them understand your approach to the question and also may drop you a hint or two if you get stuck somewhere. 

Be prepared to explain what lead you to do so. They will be highly interested in proper reasoning from your side for validating your thought process and approach. 

Do not go blank when asked for your future plans or growth plans in this role. Pause and reflect on why you're doing what you're doing and prepare and answer well in advance. Also, come prepared with at least two questions to ask the interviewers when given a chance. No questions show a lack of interest and confidence. 

Stage 2: Onsite Interview

Once you have cleared all the rounds of the first stage, you will be invited for an onsite round of interviews. This is stage 2 of the process and a more structured one. If you have made it through Stage 1, you can expect the Stage 2 to be more demanding and familiarizing at the same time. 

Stage 2 is divided into three sub-categories:

1. Coding Interview: This round will contain a set of questions similar to the ones asked at stage 1. The questions will come primarily from the language you have chosen with in-depth knowledge of it. This round would range between 20-30 minutes, followed by a short interactive round. 
2. Design Interview: The design interview at Facebook is quite a comprehensive one. The candidates are sorted on the basis of their expertise in the design environment. There are typically two types of such environments:
3. Systems Design
4. Product Design

Though the interviewers expect you to have a basic understanding of both the types, you will be allotted a panel that is specific to your expertise in designing. The idea is to help you stretch your comfortable horizons to tackle an unknown problem in a known environment. This way you will get an idea of how things work at Facebook and what kind of queries you might be expected to resolve. On the interviewer's part, they get to understand how you react to an unknown situation or what approach do you take in resolving a problem you are not familiar with. 

Preparation Tip: Walkthrough all your previous projects. What ever systems or projects you may have designed previously, on whatever scale, get a fair idea of it. Also, be prepared to answer tricky questions like "If you could, what would you change about it?", "Which part took you the most time?", "What was the one thing that put everything in place?", "Could you possibly think of a different way in which you could have designed this system?" etc. Avoid giving answers in a "no" unless you have a strong reasoning behind it. The purpose asking these questions is to understand how versatile you are and how well you can multi-task. 

Try to incorporate Facebook in your examples. Understand how Facebook works as a system and what is your take on the same as a systems designer. You might be asked for your ideas on scaling up the current system or what approach you would take if you were to redesign Facebook starting from scratch. 

Start reading early. Grasp as much information about famous design use cases as possible. You might get questioned about what went wrong with a particularly famous company that defaulted on its design part or a case study that requires analysis as a design engineer. 

Be very specific and clear about the requirements part. The fundamentals of successful design lie in appropriately identifying the requirements. Once you get on to the project, you will be expected to thoroughly go through the project details and raise requirements without a miss (adequate enough to get the project started and going). 

A similar approach would be followed for the Product design category. Questions will primarily focus on your previous projects. "How long did it take you to design a particular category of product?" "What were the major challenges you had to overcome while designing the product?", "If possible, what will you change about it?", "What if your mailing list overflows with mails?", "Have you ever dealt with system failures?", "What approach do you plan to take if there is a system failure?", "What is your back-up plan in case spammers attack the system?"

Most importantly, make sure that you are the one driving the discussion around the topic you are most comfortable in. Do not get stuck at a point or genre that you are not confident in. 

1. Behavioral Interview: This is the last stage of the interview. This part of the interview accesses the candidates for their cultural fitment. Though it is called a behavioral interview, the coding section is included in this part as well. Since Facebook is a technology-first company, they do not want to miss any chance that can help them get a better idea of a candidate's coding skills. 

The behavioral interview focuses mainly on figuring out if you could fit in the fast-paced, adhoc and mostly unstructured requirement environment at Facebook. 

For the behavioral part

• Focus on the core values of the company. Facebook has five core values that are - move fast, be bold, build social value, focus on impact and be open. The panelists typically give weightage to people who resonate with these or similar values and are ready to imbibe these in their daily practice. 
• Though there is no fixed syllabus for behavioral interviews, interviewers prefer asking questions relating to problem solving, motivation, leadership, collaboration and questions about yourself. 
• Make sure you have enough examples and instances to quote that back up almost every single achievement you have mentioned in your resume. 
• You can almost surely expect questions on conflict resolution, receiving feedback, giving feedback and related areas that tap sensitive human elements. 

Preparation Tip: Stay up-to-date with whatever is happening in the organization. Facebook is extremely fast-paced. Follow the news updates relating to Facebook and other daughter companies like Instagram etc. 

Stay true to yourself and the role you have applied for. Even if it points towards your failure or fault, speak the truth. 

Final Offer

The final offer is made by collaborating the total marks scored across both the stages and how strategically you approached the coding questions. The behavioral interview also holds a high weightage since recruiters are looking out for people who can adjust to the dynamic environment and culture across the organization. 

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