Bloomberg interview notes, page 8 of 14

Large Enterprises

Most of these Bloomberg write-ups come from Software Engineers (130), then Product Managers (2) and Data Analysts (1). The most reported rounds are the technical phone screen (100), the behavioral / leadership round (8), the onsite coding round (8) and the system design round (8).

133 interview notes · updated Oct 2026

Bloomberg·Software Engineer·Technical Phone Screen

Jun 2026

Bloomberg SWE interview with a string manipulation problem involving wildcards. Pretty straightforward recursion/backtracking territory but still worth knowing cold.

Given a string containing '0', '1', and '*' characters, replace each '*' with either '0' or '1' and return all possible resulting binary strings.

“Classic backtracking setup.”

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Bloomberg·Software Engineer·Technical Phone Screen

Jun 2026

Bloomberg coding round, one question the whole time. The problem was a linked list addition variant and they wanted two different approaches, so it wasn't just 'write the code and leave.' Felt okay about it but never heard back on outcome.

You have two linked lists where each node holds a single digit, most significant digit first. Add the two numbers they represent and return the result as a linked list. Walk through at least two approaches.

“The two-approach requirement is what tripped me up a little.”

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Bloomberg·Software Engineer·Technical Phone Screen

Jun 2026

Bloomberg SWE coding round, just one algorithm question about the Collatz sequence. Pretty straightforward if you've seen it before, less so if you haven't.

Given an integer n, write a function that returns the number of steps needed to reach 1 using these rules: if n is even, divide it by 2; if n is odd, multiply by 3 and add 1.

“Classic Collatz conjecture problem.”

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Bloomberg·Software Engineer·Technical Phone Screen

Jun 2026

Bloomberg SWE interview with a tree problem that sounds easy until you actually think through all the edge cases. Decent question, left me second-guessing my complexity analysis afterward.

You're given an unordered list of nodes, each with an id and a set of child ids (no parent pointers). Find the root of the n-ary tree. Also explain your algorithm, data structures, time/space complexity, and how you'd handle invalid inputs like multiple roots, cycles, or missing node references.

“My first instinct was just 'collect all child ids into a set, then find whichever node id isn't in it, that's your root.' Which is right, but they kept pushing on the validation side and I fumbled a bit there.”

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Bloomberg·Software Engineer·Technical Phone Screen

Jun 2026

Two coding problems back to back for a Bloomberg SWE round. The first was a string decoding thing with nested brackets, the second was a grid pathfinding problem with a fuel mechanic. Both leaned pretty heavily on knowing your data structures.

Given an encoded string where k[substring] means the substring is repeated k times (and encodings can be nested), write a function to return the fully decoded string.
Given an m x n grid with a start cell, target cell, blocked cells, and gas station cells, find the minimum number of steps to reach the target. Moving costs 1 fuel, gas stations refill your tank, and you start with a full tank of given capacity. Return -1 if unreachable.

“Stack-based solution is the move here.”

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Bloomberg·Software Engineer·Technical Phone Screen

Jun 2026

Bloomberg SWE interview with a greedy/sorting problem about splitting people across two cities at minimum cost. Pretty classic algorithmic setup but the constraint of exactly n per city is what makes it interesting.

You have 2n people, each with a cost to fly to city A or city B. How do you split them so exactly n go to each city and the total flight cost is minimized?

“My first instinct was brute force and i caught myself before saying it out loud, which was a small win.”

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Bloomberg·Software Engineer·Onsite - Coding / Algorithms

Jun 2026

Bloomberg SWE interview, five coding questions across what felt like a single technical session. Mix of classic binary search stuff, a design problem, and some grid BFS. Nothing too wild but the follow-ups on the first question caught me off guard.

Given a sorted array, find the first and last index of a target value. Return [-1, -1] if not found. Follow-ups: how do you handle efficient range queries if the array only grows at the end with larger values? What if insertions can happen anywhere while keeping the array sorted?
Design a data structure that supports adding a participant by ID, removing by ID, and picking a uniformly random participant, all in expected O(1) time.
Given a string of lowercase letters and balanced parentheses, return all characters that appear at the maximum nesting depth, preserving their order.
On an m x n grid of houses and empty cells, place one turret to protect the maximum number of houses within Manhattan distance k.
Find the shortest path from the top-left to the bottom-right of a grid, where you can break through at most k walls. Return -1 if no path exists.

“The base problem is just two binary searches, fine.”

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Bloomberg·Software Engineer·Technical Phone Screen

Jun 2026

Bloomberg SWE technical phone screen that went sideways fast. The interviewer pushed past the standard sliding window answer and wanted something else entirely, and I had nothing.

Given a string, find the length of the longest substring without repeating characters. Then explain an approach that does NOT use a sliding window or move a left pointer.

“I nailed the sliding window version, complexity and all.”

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Bloomberg·Software Engineer·Technical Phone Screen

Jun 2026

Bloomberg SWE interview with a bucketing/classification problem that looks deceptively clean on paper but has a bunch of edge cases once you start coding. The binary search path felt natural to me but they pushed on the linear merge approach too, which I hadn't thought through carefully beforehand.

Given a sorted boundaries array and an input array, classify each element into the bucket it falls into based on consecutive boundary pairs. Return the bucket index for each element or the grouped buckets, and discuss both an O(n log k) binary search approach and an O(n + k) merge-style approach.

“Started with binary search since the boundaries are sorted, felt pretty solid there.”

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Bloomberg·Software Engineer·Onsite - Behavioral / Leadership

Jun 2026

Bloomberg SE behavioral interview, about an hour, no system design at all which I didn't expect. Pretty focused on leadership and project depth, so if you're coming in thinking it'll be technical you might be caught off-armed like I was.

Walk me through the most challenging project you've worked on, in depth.
Looking back, what would you change about how you approached that project if you were starting it from scratch?
As a team lead, how would you handle a teammate who is being unreasonable or difficult to work with?
How do you decide how to distribute tasks across your team?

“This one ate up a lot of time.”

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