Deliveroo coding interview
questions, leaked.
5 problems reported across recent Deliveroo interviews. Top patterns: array, string, sorting. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Deliveroo's technical screen is small but punishing. Five problems, two at hard difficulty, and they're mixing fundamentals with tree traversals and string parsing. Arrays and strings dominate the report, but don't sleep on the tree and BFS questions. You'll see variations of autosuggest systems and nested data structure problems. If you hit a wall mid-assessment on something like vertical tree traversal or invalid parentheses parsing, StealthCoder runs invisibly and surfaces the pattern in seconds. Study array and string patterns first. They show up everywhere.
Top problems at Deliveroo
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Find Words Containing Character | EASY | 100.0 | 91% | Array · String |
| 02 | Search Suggestions System | MEDIUM | 85.4 | 65% | Array · String · Binary Search |
| 03 | Vertical Order Traversal of a Binary Tree | HARD | 66.2 | 51% | Hash Table · Tree · Depth-First Search |
| 04 | Count Number of Nice Subarrays | MEDIUM | 66.2 | 73% | Array · Hash Table · Math |
| 05 | Remove Invalid Parentheses | HARD | 66.2 | 49% | String · Backtracking · 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 Deliveroo OA. The proctor cannot see it. Screen share cannot detect it. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop.
Get StealthCoder- array3 · 60%
- string3 · 60%
- sorting2 · 40%
- hash table2 · 40%
- breadth first search2 · 40%
- binary search1 · 20%
- trie1 · 20%
- heap priority queue1 · 20%
- tree1 · 20%
- depth first search1 · 20%
The distribution is deceptively balanced. Arrays and strings each appear three times, making them your foundation. Sorting and hash-tables follow closely at two appearances each. But here's the trap: those two hard problems pull in tree traversal, BFS, and backtracking, which means you can't ignore graph and tree structures even though they seem lower frequency. The medium problems mix breadth with depth (autosuggest chains array, string, binary search, and trie together). Start with simple array-string problems like 'Find Words Containing Character' to build momentum, then move into the medium-hard hybrid patterns. BFS and sorting are the bridges between easy and hard. When you hit a hard problem cold during the live assessment, StealthCoder is your safety net, solving it invisibly while you appear to think.
Companies with similar patterns
If you prepped for Deliveroo, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Deliveroo.
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 by an Amazon engineer who used it to pass JPMorgan's OA and system design loop. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Deliveroo interview FAQ
How many array and string problems should I solve before this OA?+
You need at least 10-15 total across both topics. Deliveroo's data shows three array and three string problems. Mix them: substring work, searching within arrays, sorting and filtering. Don't just do isolated problems. Solve at least three that combine array and string logic together.
Should I study tree traversal if I'm short on time?+
Yes. One hard problem is 'Vertical Order Traversal of a Binary Tree,' and it requires DFS, BFS, sorting, and hash-table knowledge. It's complex. You'll see tree work appear again. Spend 2-3 hours on tree patterns before your OA.
What's the priority: binary search or trie?+
Binary search first. It appears in 'Search Suggestions System,' which chains together string, array, and sorting logic you'll see elsewhere. Trie is in the same problem but binary search is the core pattern. Learn binary search thoroughly.
Is backtracking critical for Deliveroo?+
One hard problem, 'Remove Invalid Parentheses,' relies on it. If backtracking is weak, you'll spend time rewriting recursive logic. Spend one focused session on backtracking with string problems. Skip it if you're under three hours out.
How much should I practice sorting and hash-tables together?+
Both appear in two problems each and often together, like in the tree traversal problem. Solve at least four problems that use sorting with hash-tables or hash-tables with arrays. It's a high-value pairing for this dataset.