Judging from the feedback from candidates that ProgramHelp has actually led, Bloomberg SWE has a very stable technical style:
We do not rely on extreme algorithms to win candidates, but use project details, engineering judgment and code quality to screen out candidates who "only know how to write questions but have never done the system".
If the projects on your resume are actually done, this process is not a disadvantage;
But if the project is too packaged, this interview will be very uncomfortable.
Bloomberg SWE Interview Process Overview
There are two rounds of technical interviews in total:
- 3 interviewers per round
- One of them is a shadow (auditor), mainly recording performance
- Each round of the process is highly consistent
Each round will go through:
- Short self-intro
- Digging deeper into resume projects
- Coding or engineering scenario questions
It should be emphasized that Bloomberg does not treat project discussions as small talk, but as part of the formal assessment.
First round of Technical Interview
Self-intro and project digging
After the self-introduction, the interviewer will start directly from the items on your resume and follow the points you mentioned.
Common inquiries include:
- Why choose this technical solution
- Were there any other options at the time?
- Can it still hold up after doubling the data size or concurrency?
- What is the most likely problem after this design goes online?
From the perspective of ProgramHelp, this paragraph is actually testing whether you have actually participated in system design, rather than just writing functional code.
Coding Question 1: Bracket matching and redundant bracket judgment
The question requirements are divided into two levels:
The first level is whether the basic bracket matching is legal.
The second level is the advanced requirement to determine whether there are redundant parentheses.
For example:
((a-d) + ((b+c)))
Although the brackets match exactly, b+c is surrounded by an extra layer of brackets that have no semantic value. In this case, false needs to be returned.
The key to this question is not the stack itself, but whether you realize:
Legal parentheses do not mean that the expression is reasonable
Common implementation ideas are:
- Use stack to handle bracket matching
- Each time a right parenthesis is encountered, check whether the corresponding left parenthesis actually contains an operator or a valid expression.
- If only a single variable or expression is wrapped, it is determined to be redundant.
This type of question is quite much in line with Bloomberg's style, focusing more on code quality and semantic judgment rather than algorithmic skills.
Coding Question 2: Multi-bank exchange rate aggregation system
The background of the question is a simplified exchange rate system:
- Different banks will continuously report exchange rates
- The new rate from the same bank will overwrite the old value
- When querying, it is necessary to return the average exchange rate of a certain currency pair in all banks
A typical feasible solution is to use multiple hash maps for split management, for example:
- Bank -> currency pair -> rate
- Currency pair -> sum
- Currency pair -> count
Things to note when adding rate:
- If the bank has reported the currency pair before
- You need to subtract the old value from sum first and then add the new value
- Avoid statistical duplication
The average value can be returned in O(1) when querying.
This question is superficially a data structure question, but it actually tests whether you have state update and consistency awareness.
Second round of Technical Interview
Deep digging of projects is still the main line
The self-intro and project discussion process in the second round is exactly the same as that in the first round, but the follow-up questions will obviously be more focused on project implementation:
- If this were Bloomberg's internal system, where would things be most likely to go wrong?
- Which designs are designed to cope with scale rather than current needs
From ProgramHelp’s experience, the second round is less tolerant of projects.
Engineering scenario question: High latency third-party API replacement
The questions in this round are more focused on system design and engineering judgment.
The given scenario is:
- A class internally calls a third-party API
- External code will loop through multiple instances of this class
- Now the original API is deprecated and needs to be replaced with a new API
- The latency of the new API is significantly higher
The interviewer's first question is usually: How can I reduce the overall latency impact?
Reasonable answers include:
- Asynchronous call
- Concurrency control
- Batching requests
- Is there cache space?
Then we will continue to ask:
What should I do if the batch upload fails?
What is examined here is the stability of the project, not "whether it will retry".
A more complete idea is:
- Distinguish whether retry is possible based on the error code returned.
- Use exponential backoff for transient errors
- Set the maximum number of retries
- Introduce fallback or failure recording mechanism when necessary
Bloomberg attaches great importance to whether you have production systems thinking on this type of issue.
Summary of core highlights of Bloomberg SWE interviews
Judging from ProgramHelp’s many practical experiences, this type of interview focuses on multiple aspects:
- Is the project real and can it withstand questioning?
- Does the code you write consider long-term maintenance?
- When facing system changes, can we make reasonable choices?
- Do you have basic but solid engineering judgment skills?
The algorithm difficulty itself is not extreme, but the requirement for "engineering sense" is quite clear.
ProgramHelp Experience suggestions
If you are preparing for Bloomberg SWE:
- Project preparation takes priority over solving puzzles
- Common data structure questions should be written very cleanly
- You must be very familiar with engineering concepts such as latency, retry, backoff, and coverage updates.
- When answering questions, start from the perspective of "what if this was an online system"
This type of company is more willing to offer offers to people who can write code stably and maintain the system for a long time.
Are you stuck with OA or having stage fright at the interview on your way to job hunting?
Want to compete with FAANG and other big companies but are unsure? A professional OA and interview service team will escort you throughout the entire process to help you easily overcome the difficulties of finding a job! OA ghostwriting covers all platforms such as HackerRank and Niuke.com, and all test cases pass 100%. There is no charge for failure, and remote traceless operation is more secure. Interview assistance is provided by North American CS experts in real time, and the precise thinking guidance far exceeds that of AI, allowing you to respond calmly;Proxy Interview Servicewith the help of camera switching and voice-changing lip-syncing technology, we can simulate and debug in advance, and cooperate with each other directly to get an offer. There is also a full set of packaged services, from OA to signing and negotiation, the whole process is followed up, a small deposit is paid in advance, and the balance is paid after receiving the offer, so you can rush to the big factory with zero risk. Mock interviews, resume packaging, algorithm coaching and other supporting services are all available. Customized solutions adapt to various job search needs, helping you avoid detours and quickly get your favorite offers!
