Meta OA has always been notorious for being "stuck in time + heavy on logic" among North American manufacturers, and this release is no exception.
My round was 4 questions / 45 minutes, and the overall difficulty was medium to high, but the questions were very "Meta" - focusing on code fluency and boundary details rather than pure algorithmic volume.
I successfully AC'd all four questions this time, and the whole experience was both intense and awesome. Here's the full replay, including questions, thoughts, time pacing, and summaries.
Topics + Ideas
T1: Dynamic Rating Tracker
You are given a list of rating changes for a website.
The initial rating is 1500. After applying all changes, return both the final rating and the highest rating ever achieved.
Question : Simulate the process of changing the score of a website. Each number represents one score change (which may be positive or negative), and requires the output of the final score and the highest ever score.
Idea:
initialization cur = 1500,max_rating = 1500. Iterate through the array of changes:
- Update Current Score
cur += delta - as
cur > max_ratingUpdate top scores
Return[final_rating, max_rating].
Points of Attention:
- If all changes are negative, the maximum score remains 1500
- Return to the format required by the question
Complexity: O(n) time, O(1) space.
T2: Bus Schedule Time Gap
Given a list of bus departure times (in HH:MM format) and a current time, return how many minutes have passed since the last bus departed. If no bus has If no bus has departed yet, return -1.
Question : Input the bus departure schedule and the current time to calculate how many minutes it has been since the last departure.
Idea:
Convert all times to minutes (e.g. "08:30" → 510).
Then:
- The current time is also converted to minutes.
- Find all ≤ current time departure moments.
- If it exists, take the maximum value and return the difference; if not, return -1.
Points of Attention:
- Returns 0 if the current time is equal to the departure time.
- Unsorted inputs need to be sorted first
- Ensuring non-negative outcomes
Complexity: O(n log n) if sorted, O(n) otherwise.
T3: Zigzag Subarray Count
Count the number of contiguous subarrays where adjacent elements alternate between even and odd numbers.
Question : Count the number of consecutive subarrays of an array with alternating parity.
Idea:
Using Variables count Records the length of the sawtooth sequence ending with the current element. Iterate through the array:
- If the current element has a different parity than the previous element, the
count += 1 - Otherwise
count = 1
accumulate at every stepcountuntil (a time)total.
Points of Attention:
- Subarrays of length 2 are also counted
- Watch out for boundaries to prevent arrays from going out of bounds
Complexity: O(n) time, O(1) space.
T4: Memory Allocator
Implement a memory allocator that supports two operations.
- Allocate memory (aligned to 8 bytes).
- Free memory by ID.
If allocation or freeing fails, return -1.
Problem: Implement a simplified version of a memory manager.
Idea:
Simulate memory space with a one-dimensional array (0 is free, 1 is occupied) and maintain a hash table alloc_map:alloc_map[id] = [start, size]
Distribution:
- Iterate through memory to find the first contiguous free block aligned by 8 bytes.
- If successful, marks and returns the starting address, otherwise returns -1.
Release:
- If the ID exists, clear the corresponding area and delete the record; otherwise, return -1.
Points of Attention:
- 8-byte alignment:
start % 8 == 0 - Repeated releases need to be determined
- Insufficient allocation to return -1
Complexity: O(n) for Allocate, O(1) for Free.
II. Summary of overall experience
Meta OA's four questions are very engineering in style, not testing difficult algorithms, but examining code implementation skills, thinking logically and boundary control.
My pacing this time was roughly as follows:
- Average 7 minutes for the first two questions.
- The third question will take about 10 minutes.
- Last question 18 minutes (debugging while writing)
The key point of the overall pass rate is:
- Question Familiarity: It helps to practice more LeetCode simulation and design type questions for this type of question.
- Boundary error-proofing: note empty inputs, single elements, formatted outputs.
- Time Management: Do not exceed 12 minutes per question.
III. Background of trainees
This student is from the US East Computer Science Master's program, usually has a good foundation for brushing up, but several times before the OA was stuck in the hidden case due to errors in details.
Passed the online interview this time with a remote voice assist from Programhelp.
IV. FAQ Frequently Asked Questions
Q1: Is Meta OA algorithmic or implementation biased?
A: Bias implementation. More about logical clarity, boundary control, and engineering habits than pure algorithmic difficulty.
Q2: Can I skip questions and go straight to the next one?
A: Yes, but it is advisable to go through all the questions quickly and prioritize to ensure that the questions that you can think of in seconds are taken.
Q3: Is there a limit to the code language?
A: Meta supports mainstream languages (Python, C++, Java, JS), Python expression efficiency is the highest, but pay attention to the time complexity.
Q4: Will the test samples be in card format?
A: Yes. Output formatting, case, and return type errors are all considered Wrong Answer. it is recommended to prepare input and output templates in advance.
Q5: What kind of assistance does Programhelp provide?
A: We provide remote and untraceable voice assists, including: real-time pacing cues, boundary reminders, and debugging strategies to help candidates complete efficiently within the time limit.
Still struggling with fall recruiting?
Many students prepare OA for Meta, Google, Amazon, Stripe and other big manufacturers, often due to time pressure or boundary problems resulting in incomplete AC.
Programhelp Provides a full, unobtrusive remote assisting service that covers the whole process:
- OA Practical Accompaniment (HackerRank / Codility / Codesignal Full Platform)
- Real-time voice prompts + Debug rhythm guide
- Simulated VO and System Design Answer Structure Training
- Behavioral Interview (Behavioral) and Technical Q&A Synchronized Coaching
The team has helped students successfully pass written tests and interviews at companies like Meta, Citadel, TikTok, Stripe, Amazon, and more.
If you, too, want to get on board for Fall 2025, check out Programhelp's one-stop shop for help.
Extended Reading
- NVIDIA OA Real Questions | Arrays and Stacks Question Review
- Stripe SDE Interview Review | Debug + System Design Practical Summary
- Databricks DS Interview Process | Recruiter → Case Study Full Explanation
