Just finished HubSpot The questions are directly LeetCode high-frequency original questions. If you usually answer questions well enough, there will be basically no major problems this round.
Coding wheel
The questions are directly LeetCode high-frequency original questions. If you usually answer questions well enough, there will be basically no major problems this round.
The question encountered in this round of interviews is "Sum of Two Numbers II - Input Ordered Array", a high-frequency question on LeetCode. Question requirements: Given an array of integers arranged in ascending order Numbers, find the sum of two numbers equal to the target value Target, return their subscripts (subscripts start from 1).
Problem-solving ideas
A pointer Left Starting from the head of the array, another pointer Right Start from the end of the array. Calculated every time Numbers[left] + numbers[right] Compare with target value:
- If it is equal to the target value, return directly
[left+1, right+1] - If it is less than the target value, it means a larger number is needed.
LeftMove right - If it is greater than the target value, it means that a smaller number is needed.
RightShift left
In this way, the answer can be found in one traversal, and the time complexity is O(n), space complexity O(1).
Reference code (Python)
Def twoSum(numbers, target):
left, right = 0, len(numbers) - 1
while left < right:
current_sum = numbers[left] + numbers[right]
if current_sum == target:
return [left + 1, right + 1] # The question requires the subscript to start from 1
elif current_sum < target:
left += 1
else:
right -= 1
return [] # If there is no solutionSystem Design (SD) Wheel
This round of questions is very classic:Design Netflix / YouTube ——Design a large-scale video streaming system.
This type of question is called the "Hello World" of SD interviews. It is not difficult to answer, but it is not easy to answer it well.
Problem-solving ideas
Start with requirements clarification and distinguish between functional requirements and non-functional requirements. Functional requirements include video uploading, video playback and search functions; non-functional requirements mainly focus on high concurrency, low latency and high availability. In the video playback scenario, usability is more important than consistency, because users care more about smooth video playback rather than strictly synchronizing the latest status every time.
Next is the core component design. I focused on the three major modules of CDN, Blob Storage and Metadata database. CDN ensures low latency for global users to access videos; Blob Storage (such as S3) is used to store original videos and transcoded video files; the Metadata database stores the title, description and user information of the video. Since more reading is done and less writing is done, it can be combined with caching to optimize performance. The data flow and interaction between components also need to be considered during design to ensure that the system is scalable and reliable.
Finally, there is the video processing process: the user uploads the video → enters the queue → the transcoding service generates different definition versions → stores it in Blob Storage → CDN warm-up. This process ensures that videos can be quickly distributed and played after uploading, while supporting high concurrent access.
My experience is that when talking about system design, you must be clear and organized: first talk about the requirements, then show the high-level architecture, and finally go into the core components. At the same time, the interviewer is very concerned about your ability to make trade-offs in design, such as caching strategies, database selection, and CDN usage strategies. Using a whiteboard or online drawing tool to draw the entire process will make the plan more intuitive and make it easier for the interviewer to understand your thinking.
Summary and suggestions
- Coding: Review the questions thoroughly, communicate ideas first, and proactively check the complexity after writing.
- System Design: Practice more classic questions. The key is to have clear architectural ideas and be able to clearly explain the role and trade-off of each component.
- Communication is important: Whether it is Coding or SD, the interviewer hopes to see that you have clear logic, clear ideas, and can take the initiative to discuss.
Let us help you
If you are about to participate in an interview with HubSpot or other major North American SaaS companies, but you are not confident enough in the coding or system design aspects, don’t worry! Programhelp provides professional Interview assistance service, we have helped hundreds of students successfully obtain OFFER, so that you can also meet the interview challenge in the best condition.
