SIG coding interview
questions, leaked.
7 problems reported across recent SIG interviews. Top patterns: array, simulation, string. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
SIG's interview hits you with seven problems across a narrow range: one easy, four medium, two hard. Arrays dominate the list, appearing in five out of seven reported questions. Simulation and string manipulation show up repeatedly. If you're interviewing there, you're walking into a gauntlet of array traversals, matrix simulations, and tree validations. The good news: the problem set is small and predictable. The bad news: when you're live on their assessment and your mind blanks on spiral-matrix logic or binary-search-tree validation, there's no time to Google. That's where StealthCoder runs invisible in the background, surfacing a working solution the moment you need it.
Top problems at SIG
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Validate Binary Search Tree | MEDIUM | 100.0 | 34% | Tree · Depth-First Search · Binary Search Tree |
| 02 | Text Justification | HARD | 92.2 | 48% | Array · String · Simulation |
| 03 | Number of Black Blocks | MEDIUM | 71.1 | 39% | Array · Hash Table · Enumeration |
| 04 | Block Placement Queries | HARD | 71.1 | 17% | Array · Binary Search · Binary Indexed Tree |
| 05 | Kth Largest Element in an Array | MEDIUM | 71.1 | 68% | Array · Divide and Conquer · Sorting |
| 06 | Add Binary | EASY | 71.1 | 56% | Math · String · Bit Manipulation |
| 07 | Spiral Matrix | MEDIUM | 71.1 | 54% | Array · Matrix · Simulation |
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 SIG 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- array5 · 71%
- simulation3 · 43%
- string2 · 29%
- hash table1 · 14%
- enumeration1 · 14%
- binary search1 · 14%
- binary indexed tree1 · 14%
- segment tree1 · 14%
- tree1 · 14%
- depth first search1 · 14%
Array problems anchor this interview. Five of the seven problems touch arrays, and they span multiple patterns: spirals, binary search on sorted arrays, enumeration across blocks, and heap-based selection. Start there. Simulation and string manipulation appear in three and two problems respectively, often intertwined with arrays (text justification combines both). Tree problems are lighter in volume but harder: Validate Binary Search Tree sits at medium difficulty and tests recursion and constraint checking. Binary-indexed-tree and segment-tree problems appear in Block Placement Queries, a hard problem that ties arrays to range queries. Don't underestimate the math and bit-manipulation surface area. When you hit the live assessment, array drills come first, tree validation second. If you freeze on a segment-tree query or a simulation edge case mid-OA, StealthCoder is your hedge, solving it in seconds while the proctor sees nothing but your thinking.
Companies with similar patterns
If you prepped for SIG, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass SIG.
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.
SIG interview FAQ
How many array problems should I solve before SIG's interview?+
Drill at least 10 to 15 array problems beyond the five reported here. Arrays appear in over 70 percent of SIG's problems. Focus on spiral traversal, binary search variants, and enumeration patterns. You'll see array manipulation in almost every round.
Is tree knowledge required for SIG, or can I skip it?+
Don't skip trees. Validate Binary Search Tree is a medium-difficulty problem reported in their set. Tree traversal (DFS) and BST constraint checking are live-interview staples. Spend three to five hours on recursion and in-order validation.
What's the hardest topic I'll face at SIG?+
Block Placement Queries combines array, binary search, binary-indexed-tree, and segment-tree concepts into one hard problem. It's the outlier. If range queries and tree data structures aren't in your toolkit, start there and budget extra time.
Should I prioritize simulation problems or string manipulation?+
Simulation first. Three problems involve simulation logic, including Text Justification (hard) and Spiral Matrix (medium). Both require careful state management and edge-case handling. String work is secondary but tied to simulation, so they reinforce each other.
Can I pass SIG's interview without knowing segment trees?+
You can try, but Block Placement Queries (reported hard) uses both binary-indexed-tree and segment-tree. If you see it live and haven't studied those data structures, you're guessing. Budget four to six hours on range-query trees before the OA.