Goldman Sachs OA has always been a bit "out of the ordinary". Unlike other financial companies that favor mathematical derivation or SQL cases, the questions it comes up with are more like algorithmic competitions - clear logic, high implementation requirements, and a bit of engineering flavor. The two questions I encountered this time, one of them is on data structure and the other one is on number theory optimization, both of them are quite ingenious, belonging to the type of "I will think about it for half a day after finishing it".
Interview Overview｜Goldman Sachs OA Overall Process and Difficulty Summary
This overall Goldman Sachs OA experience can be summarized in three words:Fast-paced, deep-thinking, detailed.
There are only two questions, but they are not "boilerplate" questions, but more like mini-systems questions that combine algorithms, implementations, and reasoning.
Testing process
- Platform: HackerRank
- duration: approximately 90 minutes (two questions)
- language restriction: Optional Python / C++ / Java
- difficulty: Upper-middle (more like hardcore logic questions, not biased towards math calculations)
Generally, Goldman's OA looks at three areas:
- Data structures and implementation capabilities: depends on your flexibility in choosing the right structure (queue, hash, sorted table, etc.);
- Algorithms and Complexity Control: The questions are not large, but they all require efficient realization within the time frame;
- Logic and Boundary Thinking: In particular, consider details such as data flow updates, synchronized deletions, and range statistics.
The style of the two questions this time was very typical:
- first question Log Buffer Analyzer favorable balance of trade System implementation + data structure synergy.;
- second question Password Lock Decryption favorable balance of trade Number Theory + Thought Optimization.
Question 1: Log Buffer Analyzer
Problem.
Implement a circular log buffer that stores logs with timestamps and tags.
Every time a new log comes in:
- If the buffer is full, delete the oldest one first;
- Then immediately "send" all logs with the same label and within the specified time frame;
- Finally, figure out how many were sent throughout the process.
Ideas
This question looks like an implementation question on the surface, but it actually tests your proficiency in combining data structures.
What I was doing was:
- expense or outlay queue Maintain the log order to ensure that the oldest can be deleted quickly;
- For each tag, create a sorted list Save timestamp;
- New logs are inserted with the binary search Find the number of logs with the same label in the "time range" and add it to the result;
- If the buffer is full, the header log and its timestamped records are deleted synchronously.
In fact, it is quite like the kind of system design "streaming log + time window" processing questions, focusing on synchronization of updates and boundary control.
With the right mindset, the whole process can be stabilized in the O(log n) Grade, very silky.
Question 2: Password Lock Decryption
Problem.
Given an integer array and a maximum upper bound, the
you can spend 1 unit of cost to change any element to a number ≤ upper bound.
Find a candidate number that is coprime with all elements after modification.
Define.
Lock Code = candidate_number - total_modification_cost
Goal: maximize the Lock Code.
Ideas
This question is actually quite interesting, it looks like a brain teaser, but it's essentially number theory + enumeration + gcd optimization.
- Enumerates candidates from the maximum limit downwards;
- For each candidate, compute its gcd with respect to each number in the array;
- If gcd > 1, it takes 1 to change this number;
- Then calculate lock code = candidate - modification cost;
- Finally the maximum value is taken.
The difficulty with this question is:
Sometimes the high candidate is big but the number of changes to be made is also big, rather than cost-effective.
Therefore, we need to find a balance between "high value" and "low modification cost".
Goldman Sachs OA Frequently Asked Questions FAQ
We have compiled some of the most frequently asked questions by our students when preparing for Goldman Sachs OA, and we hope that it will help you avoid pitfalls and take fewer detours in advance.
💬 Q1: On what platforms does OA at Goldman Sachs typically take place?
Usually in HackerRank It is conducted on the platform in the form of two programming questions.
There will be multiple hidden test cases for each question, and you will have to pass all of them to count as an "AC".
Also used in some years Codility Or CodeSignal The situation, but the question style is basically the same: biased logic + implementation, not brush the template can be seconds of the type.
💬 Q2: What is the approximate level of OA difficulty?
The whole belongs to moderately difficult.
It's not the kind of data structure that's just hard, but the logic is designed to be complex and boundary-rich.
Goldman's questions are generally "clean":
- The title page does not go around the bend;
- But you're needed.Combining multiple structures to solve problems.
This Log Buffer Analyzer, for example, is actually a combined exam of Queue + Binomial Lookup + Hash Table;
Password Lock Decryption uses gcd, pruning, and number-theoretic thinking.
💬 Q3: Does Python work? Will it time out?
It can be used, but it has to be written efficiently enough.
Python runs on HackerRank with a loose time cap, as long as there is no O(n^2) The violence of the operation is usually not a problem.
Recommended Use bisect Module,collections.deque and other built-in structures that can significantly increase speed.
If you are more familiar with Java or C++, then performance in Goldman Sachs OA will be more consistent.
💬 Q4: Is the examination focused on algorithms or implementation?
Both.
Goldman Sachs' OA is more of an "engineering mindset + algorithmic logic combination".
In a nutshell:
- You don't need to memorize templates;
- But you must be able to write fluid, scalable logic.
They're more interested in seeing if you can build a "reasonably efficient system" in a limited amount of time - not a violent pile of code.
💬 Q5: Are the topics fixed?
Not fixed, but not much variation.
Common question types include:
- Streaming data processing (Log/Buffer/Queue)
- Number theory and optimization (gcd, enumeration, minimum cost)
- Simulation + data structure synthesis questions
There will be slight changes from year to year, but the core idea is pretty much the same.
The Programhelp community has compiled a database of questions from the last three years that you can practice against.
💬 Q6: What if I fail part of the test?
If you don't pass all the tests, don't panic.
HackerRank's system only shows visible test cases, hidden ones don't pass generally:
- Incomplete boundary handling (e.g., not updating the tag map synchronously after deleting the head of the queue);
- Slightly higher time complexity (forgot to add pruning or bisection);
- Fractional / time range calculations when off by one.
You can resubmit (usually 2 chances) or contact the recruiter to explain the situation and resend the test link.
💬 Q7: How long does it take to receive an interview invitation after OA is passed?
Usually within 3 to 10 days.
Goldman's hiring process favors centralized batch processing, so there may be a wait.
After passing the OA, you will basically enter the Technical Phone Interview stage.
💬 Q8: How do Programhelp's assists work?
Programhelp offers two types of OA assistance:
- Real-time voice assistance: You write it yourself, and we remind you of logic points (e.g., bisection boundaries, gcd pruning) in real time with voice alerts.
- Remote and seamless online assistanceToDesk: Secure access through ToDesk helps you pass all test cases, no charge if you don't pass.
The whole process is seamless, secure, and compatible with major platforms such as HackerRank / Codility / CodeSignal.
Many students have used this service in Goldman OA, and it saves a lot of debugging time, as well as getting through hidden cases.
Want to take down Goldman Sachs OA?Don't take it on yourself!
At Programhelp, we've helped hundreds of students secure OA at top investment banks like Goldman Sachs, JP Morgan, Morgan Stanley, and more.
Whether it is a real-time voice assistant reminder, remote secure on-line ghostwriting, or simulated interviews to restore the question training, there are mature processes and security mechanisms.
The services we offer include:
OA Total Assistance: HackerRank / CodeSignal / Codility platforms with no trace assistance and superb pass rates;
Voice real-time alert system: Real-time prompts for key points in the background while you are working on a question, without interrupting or leaving a trace;
Question Review + Answer Logic Explanation: Help you quickly eat through Goldman OA common question types;
Mock Interview Boot Camp: Covers full modules on data structures, algorithms, number theory, and system design.
If you are also preparing for OA / Interviews at Goldman or other Finance majors these days, you can contact us directly.
You can pass the test without relying on luck. Let a professional help you with the hardest part.
