Recently many students are preparing Roblox oa 2026 , here I share a classmate’s latest Roblox OA review, covering two high-frequency questions: matrix missing value sorting question and stock return maximization question. This article will fully present the question ideas, code implementation, and potential test points to help you master everything from logical reasoning to code optimization.
Roblox interview overall process
1. Resume submission and application review
After submitting your resume, Roblox's system or recruiting team will conduct a preliminary review of the application materials. Candidates who meet the job requirements will receive an Online Assessment (OA) invitation.
2. Online Assessment (OA)
Roblox’s OA is the first step in the hiring process and is used to assess a candidate’s overall abilities (not just coding, but also problem-solving, analytical and communication skills):
- OA may include multiple modules, such as:
- Problem-Solving tasks (logic/reasoning type)
- Situational judgment/decision-making questions
- Coding challenge (possibly on HackerRank or CoderPad)
- There may also be behavioral/communication writing questions, etc.
- After completion, the results will be used to decide whether to advance to the next round.
3. Recruiter phone/initial contact
After passing the OA, the recruiting team usually arranges a short phone call or video communication to introduce the team, confirm information, and understand the candidate's motivations.
4. Technical interview / virtual on-site interview
If you successfully pass the previous OA and preliminary screening, you will enter a more in-depth technical interview stage, including:
- 1–2 rounds of technical programming interviews
- System design or architecture questions (depending on the position)
- Behavioral interview or project experience discussion
These interviews are usually conducted via video conference, but in-person interviews may also be arranged.
5. Offer and internal review
After the technical interview is completed, Roblox will submit the candidate's resume, OA performance, and interviewer ratings to the internal review committee. If all stages are passed, HR will notify you to issue an offer.
Problem 1: Missing Value in 4×4 Squares and Rearrangement
Problem Description
You are given a large matrix composed of several 4×4 submatrices. Each 4×4 block contains unique numbers from 1 to 16, but one number is missing in each block Your task is to find the missing value in each 4×4 submatrix, then sort all submatrices in ascending order based on their missing value (keeping the Your task is to find the missing value in each 4×4 submatrix, then sort all submatrices in ascending order based on their missing value (keeping the original order for ties), and finally reassemble them into one complete matrix.
Approach
Python code implementation
def solution(mat): n = len(mat[0]) // 4
n = len(mat[0]) // 4
sub_matrices = []
for i in range(n): sub = [row[4*i:4*(i+1)] for row in mat].
sub = [row[4*i:4*(i+1)] for row in mat]
total = 136
current_sum = sum(sum(row) for row in sub)
missing = total - current_sum
sub_matrices.append((missing, sub))
sub_matrices.sort(key=lambda x: x[0])
result = []
for row in range(4).
new_row = []
for _, sub in sub_matrices.
new_row.extend(sub[row])
result.append(new_row)
new_row.append(new_row)
summary of an exam point
- Slicing and reorganizing 2D arrays
- Sorting stability (tiebreak by original order)
- Python List Derivative and Matrix Manipulation Proficiency
Problem 2: Maximize Stock Bot Revenue
Problem Description
You are given two arrays. prices And algo, where prices[i] represents the price of the stock on day i, and algo[i] indicates the bot's action: 0 means "buy", and 1 means "sell".
You can choose a consecutive window of k days and force the bot to sell (set algo[i] = 1 within that window). Return the maximum total revenue achievable after applying this change.
Approach
- Compute original revenue
- If
algo[i] == 1, addprice[i] - If
algo[i] == 0,subtractprice[i]
- If
- Use sliding window to find best gain
- Converting a buy (0) to sell (1) increases revenue by
2 * price[i] - Compute the maximum sum of such changes over any k-day window.
- Converting a buy (0) to sell (1) increases revenue by
- Final revenue
final_revenue = original_revenue + max_window_gain
Python code implementation
def solution(prices, algo, k).
original_revenue = 0
for price, action in zip(prices, algo): original_revenue += price if action == 1 else -price
original_revenue += price if action == 1 else -price
changes = [2 * price if action == 0 else 0 for price, action in zip(prices, algo)]
max_change = current_change = sum(changes[:k])
for i in range(k, len(changes)): current_change += changes[i.d.].
current_change += changes[i] - changes[i - k]
if current_change > max_change.
max_change = current_change
return original_revenue + max_change
summary of an exam point
- Sliding Window Technique
- Time complexity optimization O(n)
- Python
zipwith list-deductive applications - Logic modeling of investment income scenarios
Summary and recommendations of experience
The difficulty of Roblox OA is mainly in the flexible use of data structures and the completeness of algorithmic thinking.
These two questions, although the semantics are not complex, but the implementation is easy to get stuck in the matrix partition and window movement logic. It is recommended that you focus on mastering them when brushing up:
- Array slicing, matrix splicing operations
- Prefix Sum and Sliding Window Tips
- Code Stability and Boundary Control
From practical experience, most of the students who passed Roblox OA performed better in terms of logical clarity and code standardization. If you have enough time, you can practice more questions similar to Google Kick Start or LeetCode Medium, which are similar in style.
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