Cracking The Meta Coding Interview

Introduction

You can expect one coding round at the phone screen stage, and at least 2 at the onsite rounds. These rounds can be one of the most challenging, and also one of the easiest among the major tech companies. It all depends on how you prepare and there's an element of luck too. They tend to recycle questions (with variations), so it can be a walk in the park, but the tight time constraints make it difficult to figure things out on the fly. This guide will equip you with everything you need to know/do to maximise your chances. Let's start with some quick things to note about Meta coding interviews:

• Question Recycling: Meta often recycles interview questions, typically with variations, allowing candidates to potentially face familiar problems. This is both good and bad; more on this later.
• Tolerance for Bugs: While precision in coding is valued, Meta does not require perfect code and is known to be forgiving of minor bugs.
• Time Constraints: Meta interviews are extremely time-constrained; there is a need for quick recall, thinking, and rapid problem-solving.
• Hiring Bar: Given the competitive nature of these interviews, aim for a 'hire' decision in all rounds. In this market (2023/2024), we've seen candidates just miss out on an offer even after nailing 5 out of 6 coding questions.
• Career Impact: Meta ranks among the highest paying tech employers, with significant opportunities for rapid advancement for top performers. The effort put into preparing for their interviews can lead to substantial long-term benefits.

Meta Interview Conditions

Preparing for a Meta coding interview requires a deep understanding of the unique conditions you'll face. Here’s what to keep in mind as you prepare:

• No Code Execution: At Meta, you won’t have the opportunity to run your code during the interview. Being good at writing correct and optimal code, ideally on the first try, will improve your odds greatly.
• Time Constraints: Each Meta coding interview typically includes two questions to be solved in 35 minutes—this means about 15-20 minutes per question, encompassing easy to medium difficulty levels. Effective time management is critical; you need to allocate enough time not only for coding but also for dry-running your code and engaging with the interviewer.
• Mock Interviews: Meta provides an opportunity to participate in a mock interview with one of their interviewers. This can be scheduled through your career profile on their website. Failing this won't have any negative impact.
• Flexible Scheduling: Meta's interview scheduling is highly flexible; reschedule if you aren't confident enough. The bar and competition are so high that you're better off rescheduling than going in not interview-ready. More on what it means to be interview-ready later.
• Question Patterns: Meta is known to repeat interview questions, albeit with variations. While this could give you an edge if you encounter familiar problems, beware of the autopilot trap—solving a remembered problem rather than the one actually presented, which can lead to critical mistakes that are difficult to recover from.
• Interviewer Engagement: Effective communication with your interviewer is essential. You must demonstrate a clear understanding and articulation of your thought processes, coding decisions, runtime complexities, etc. Keeping the interviewer informed and engaged throughout your problem-solving process is key.
• Initial Icebreaker: Although coding is the primary focus, interviews typically start with a brief discussion about your past experience. This serves as an icebreaker and a gentle entry into the more intense coding challenges.
• Vague Questions: Unlike some online platforms, do not expect detailed questions with sample input and output. Be prepared to engage actively with your interviewer to clarify vague questions.
• Dynamic Programming: While important to understand, dynamic programming questions are rarely emphasized in Meta interviews, so deprioritize these in your preparation. There's a rumor that they've banned questions on this topic.

Checklist of Essential Skills for Meta Interviews

To succeed in a Meta coding interview, it's crucial to excel in specific skills that align with their evaluation criteria: Communication, Problem Solving, Coding, and Verification. The below checklist outlines specific skills you should focus on during your preparation; if you're good at all of these, you're interview-ready:

• Crafting Correct Solutions Quickly: You should be able to devise correct solutions within five minutes.
• Crafting Optimal Solutions Quickly: Being correct isn't enough; you also need to be able to come up with optimal solutions fairly quickly. You most likely won't have time to implement a suboptimal solution and then optimize it if the optimal solution is radically different.
• Avoiding Autopilot: You should be able to avoid the autopilot trap, where you solve a problem you remember rather than the one presented. You need to be good at sticking to the requirements of the problem.
• Time Management: You should have a time allocation for different phases e.g., for a 15-minute challenge: 3 mins for solution crafting, 5 mins to implement, 5 mins to dry-run, and 2 mins to engage with the interviewer. (You can see that time is tight)
• Writing Bug-Free Code Quickly: You need to be good at implementing your intended solution with little or no bugs.
• Dry Running Code: Since you can’t execute your code, practice dry running your solutions mentally. This means using test cases to verify your code and ensure it works as intended. If you haven't practiced this, you will likely struggle, especially if you're used to running your code.
• Context Switching: You should be comfortable switching between different cognitive tasks: from problem-solving and coding to engaging with the interviewer. This includes responding to hints, addressing questions that may seem tangential, and defending your decisions.
• Confidence and Body Language: Even if you're correct, coming across as unsure won't inspire confidence in the interviewer. You should be able to defend your decisions confidently and maintain positive body language throughout the interview.

If you are good at all of these and have practiced with Meta's questions, then you're interview-ready.

Recommended Preparation Strategies

Step 1: Build a Strong Foundation

• Identify Weaknesses: Start by assessing your understanding of data structures and algorithms. Identify areas where you need improvement and ensure to plug any gaps.
• ⚡ If you prefer some hand-holding and want an accelerated learning path, you can try out our crash courses here.
• 💡 You can also use our Diagnostic Tests to evaluate your knowledge and identify areas for improvement.

Step 2: Context Pre-Loading and Mental Problem Solving

Mental Run-Throughs: Go through a list of common Meta problems (around 100-200). Instead of coding the solutions at first, you can first mentally solve them i.e. attempt to come up with an optimal solution and layout the code mentally. If you can do it mentally, then coding it up is just typing. The advantage of doing this mentally is that the cognitive load is lower, and you can get to a state where you're familiar with Meta's problems in a shorter time. If you're stuck after 10 mins, check the solution and understand it.

• Try to code up the solutions to some of the problems, especially the ones you weren't able to solve mentally.

Step 3: Practice Under Time Constraints

Timed Practice: Simulate the interview environment by practicing coding under time constraints—aim to solve two problems within 35 minutes.

• Implementation: Focus on implementing both familiar and unfamiliar problems within these time limits.

Step 4: Human-in-the-Loop Mock Interviews

Mock Interviews: Engage in multiple mock interviews. Use the free mock interview offered by Meta and consider additional sessions with professional interviewers who can give realistic hire decisions and feedback. You can also mock with your friends, but mocking with an interviewer is strongly advised.

• Success Rate: Aim for a success rate of at least 80% in these mock sessions, which indicates readiness. For instance, if you undertake ten mock interviews, and are getting a hire decision in 8 or more, that's a good signal of your readiness.

Step 5: Coding Quickly with Minimal Bugs

Speed and Accuracy: Practice thinking of solutions in a programmatic way, and translate your solutions into code while minimizing errors.

• Skeleton code & checklists: Develop a habit of writing skeleton code and using checklists to ensure you implement your intent and cover all requirements. Do not rely on your short-term memory. Under pressure, you're likely to forget things, and one omission can lead to a no-hire decision. For example, if the problem asks for descending order, and you do an ascending order, this can cost you the offer.

Step 6: Avoid Burnout

Sustainable Preparation: Ensure you don't compromise your health during preparation. Get adequate sleep, take regular breaks, and maintain a balanced diet. Exercise, get sunlight, etc. You need to be in peak condition during your interviews.