BILL Holdings coding interview
questions, leaked.
1 problems reported across recent BILL Holdings interviews. Top patterns: array, depth first search, breadth first search. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
BILL Holdings has a narrow but deep assessment window. They're asking one medium-level problem that tests graph traversal and spatial reasoning. The problem, Number of Islands, combines array manipulation with DFS/BFS logic and union-find patterns, all on a 2D grid. A single well-executed solution here can carry you through. If you freeze mid-interview, StealthCoder runs invisibly during screen share and delivers a working implementation in seconds, no proctor visibility. You need to understand the core patterns, not memorize variations.
Top problems at BILL Holdings
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Number of Islands | MEDIUM | 100.0 | 62% | Array · Depth-First Search · Breadth-First Search |
Frequencies derived from public community-tagged interview reports. Click a row to view on LeetCode.
You have a week, maybe less. You can't out-grind the list above. StealthCoder runs invisibly during the actual BILL Holdings OA. The proctor cannot see it. Screen share cannot detect it. Built because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround.
Get StealthCoder- array1 · 100%
- depth first search1 · 100%
- breadth first search1 · 100%
- union find1 · 100%
- matrix1 · 100%
This is a topology and connectivity problem set. BILL isn't testing breadth. They're testing depth on one core pattern: can you identify connected components in a matrix and traverse them efficiently. DFS, BFS, and union-find all solve the same underlying shape, so understanding which approach fits the constraint matters more than memorizing syntax. Array and matrix handling are table stakes. The medium difficulty signals they expect clean logic, not brute force. You should be comfortable implementing DFS recursively or BFS iteratively before the interview. If you hit a wall on the live assessment and can't remember union-find syntax or the grid traversal order, StealthCoder surfaces the correct approach instantly.
Companies with similar patterns
If you prepped for BILL Holdings, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass BILL Holdings.
Memorizing every problem above in a week is a fantasy. StealthCoder is the hedge: an AI overlay that's invisible during screen share. It reads the problem on screen and surfaces a working solution in under 2 seconds. Built because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround. Works on HackerRank, CodeSignal, CoderPad, and Karat.
BILL Holdings interview FAQ
Should I practice DFS and BFS separately or just master one?+
Both appear in BILL's problem set. Master DFS first (simpler to write recursively on a grid), then learn BFS as a backup. They solve the same Number of Islands problem differently. Knowing when to pick each matters more than doubling drill time on one approach.
Is union-find worth studying for this assessment?+
Yes. Union-find solves Number of Islands efficiently without recursion or queue overhead. BILL's problem list includes it as a tag, signaling it's a valid solution path. Learn the core union and find operations, then apply it to grid connectivity once you've mastered DFS.
How much matrix and array manipulation do I need?+
For Number of Islands, you need to iterate 2D grids, mark visited cells, and check neighbors. It's not complex array logic, just clean indexing and boundary checks. One medium problem won't test advanced array slicing or transformations.
What if I only have time to drill one graph traversal topic?+
Pick DFS on a 2D grid. It's shorter to code, recurses naturally, and solves BILL's problem directly. BFS works too, but DFS requires fewer lines and less setup. Spend your time coding it three times cleanly rather than splitting focus.
Is one medium problem enough to pass BILL's assessment?+
One problem means the execution matters heavily. A correct, well-commented solution with clean traversal logic should satisfy their bar. There's no second problem to salvage a weak attempt, so focus on understanding the problem deeply, not just getting to 'working code'.