Bloomberg Fresher Interview Questions
Bloomberg sells financial data, news and analysis to people who work in finance, including through the Bloomberg Terminal. A campus hire is not expected to know markets already. Prepare to show strong fundamentals in data structures, care about numbers being exactly right, and college projects where speed and correctness both mattered. Show that you can pick up finance words quickly. What to show here: careful fundamentals and care that every number is right. Each question below has what the interviewer is checking, an answer frame and a sample spoken answer to adapt.
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1. Tell me about a college project where you found that a number your own program produced was wrong. How did you find it and what did you do next?
- Describe the project and the number that was wrong.
- Explain how you noticed it.
- Show how you traced the cause.
- Say what check you added so it could not come back.
“In my final year project, your project, my program printed an average that looked too neat. I worked the same sum by hand for a few rows and got a different answer. I traced it and found I was dividing whole numbers, so the decimal part was dropped. I fixed the type, then told my teammates because two of their charts used my output. After that I added a small test that compares the program to a hand-worked example. It took little time and caught one more mistake later, which was your result.”
Weak answers say the numbers were never wrong, or fix the bug quietly without telling the people who used the output.
2. Finance has many words a computer science student has never heard, like bond, yield or bid. Tell me about a time you had to learn an unfamiliar subject fast to finish a piece of work.
- Name the subject and why you needed it.
- Explain how you learned: who you asked, what you read.
- Show how you checked that you understood.
- Share what you built with it.
“During my internship at your company I had to build a small report for an accounts team, and I did not know their terms. I wrote down every word I did not understand in the first meeting and asked one team member to explain them with a real example. Then I wrote the rules back in my own words and asked her to correct them. Two of my notes were wrong, which was good to learn before coding. The report worked on the first review. I would learn market terms the same way, one real example at a time.”
Weak answers pretend to know the subject already, or describe building something without ever checking their understanding with an expert.
3. Prices for thousands of shares arrive every moment. Which data structures would you use to keep the latest price of each share and also show the ten biggest movers of the day?
- Use a hash map from share symbol to latest price for quick lookup.
- Work out the change from the opening price on each update.
- Keep a heap or a sorted structure for the biggest movers.
- Explain the cost of an update and of reading the top list.
“For the latest price I would use a hash map with the share symbol as the key, so each update and each lookup is quick. For the biggest movers I need ranking. I would store the opening price with each share and work out the change on every update. Then I would keep a small heap of the top movers, or a balanced tree ordered by change, and adjust it when a share moves in or out of the list. I would also ask how often the screen reads the list, because if it reads rarely, sorting only when asked may be simpler.”
Weak answers sort the full list on every price update, or name a structure without saying what each operation costs.
4. Why can it be risky to store a share price in a floating point variable, and what would you use instead?
- Explain that binary floating point cannot hold many decimal fractions exactly.
- Give a simple example of a sum that comes out slightly off.
- Offer options: whole numbers of the smallest unit, or a decimal type.
- Mention rounding rules and comparing values.
“Floating point stores numbers in binary, and many decimal fractions have no exact binary form. So a price can be held as a value that is a tiny bit off. One value is harmless, but after adding many of them, or comparing two prices for equality, the error shows. I would store the price as a whole number of the smallest unit, with the number of decimal places kept beside it, or use a decimal type if the language has one. I would also agree one rounding rule and apply it in one place, not in every function.”
Weak answers say floating point is fine if you round at the end, or cannot explain where the error comes from.
5. Two updates for the same share reach your program in the wrong order because of the network. How does the program decide which price is the newer one?
- Do not trust arrival order.
- Use a sequence number or a time stamp set by the source.
- Keep the last sequence seen for each share and drop older updates.
- Say what to do when a gap shows that an update is missing.
“I would not use the order of arrival, because the network can change it. Each update should carry a sequence number from the source, or at least the time the source created it. My program keeps the last sequence number it applied for each share. If a new update has a lower number, it is old and I drop it. If the number jumps ahead, I know something is missing, so I would ask the source to send it again or reload the current state. I prefer sequence numbers over clocks, since two machines rarely agree on the exact time.”
Weak answers use the time the message arrived, or never consider that an update might be lost.
6. A user types the first letters of a company name and wants suggestions at once. Which structure would you build for this, and how would you rank the suggestions?
- Name a structure for prefix search, such as a trie.
- Explain how a lookup walks the letters typed.
- Describe ranking, for example by how often a company is searched.
- Mention memory use and names typed with small mistakes.
“I would use a trie, where each node is one letter and a path spells a name. When the user types, I walk down the letters and collect the names below that node. To avoid collecting a huge list, each node can keep a short list of its most searched names, so the answer is ready at once. For ranking I would use how often people pick each company. A simpler choice is a sorted list with binary search on the prefix, which uses less memory. In a college project I built your project with the sorted list first, then measured.”
Weak answers scan every name on each key press, or ignore ranking so the most useful company is buried.
7. On your first small task you ship a change, and the next morning a user reports that one screen now shows yesterday's closing price as the live price. What do you do?
- Tell your mentor or lead at once with what you know.
- Confirm the problem and check whether your change caused it.
- Undo the change if that is the fastest safe fix.
- Find the cause, add a test and write down what happened.
“I would tell my mentor straight away, even before I know the cause, because a wrong price on screen can hurt someone's decision. Then I would check if I can see the problem myself and whether it started with my change. If it did, I would ask to roll the change back first, since that protects users fastest. After that I would find the real cause calmly, write a test that fails on the old code, and fix it properly. I would also write a short note on what happened, so others can learn from my mistake.”
Weak answers try to fix it alone and quietly, or spend a long time searching for the cause while users still see the wrong price.
8. Why do you want to start your career building software for people who work in financial markets, and why Bloomberg?
- Say what kind of engineering problem interests you.
- Connect it to what Bloomberg makes: financial data, news and the Terminal.
- Be honest about what you still need to learn.
- Say how you want to grow.
“I enjoy problems where data arrives fast and still has to be exactly right. In my college project, your project, the hardest and most fun part was keeping results correct while updates kept coming. Bloomberg provides financial data and news that people use to make real decisions in the moment, so that problem is the daily work here at a much larger size. I do not know finance well yet, and I would like to learn it alongside the engineering. I want to become someone who can be trusted with systems where a small error matters.”
Weak answers talk only about the brand or the office, or show no idea what the company's products do.
No figures on this page: pay depends on the level, the city and the offer in front of you. When the offer comes, the free salary negotiation script helps with that part.
The questions above are the prep. On the real call, ClapAssist helps with the ones you did not practice.
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