ServiceNow Coding Interview Questions
26 ServiceNow coding interview problems with full optimal solutions — 15 easy, 8 medium, 3 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an ServiceNow interviewer values, and a FAQ section.
Showing 10 problems of 26
- #4easysometimes asked
4. Remove Duplicates from Sorted Array
Strip duplicates from a sorted array in place, returning the new length. ServiceNow uses this to test the slow/fast two-pointer pattern they apply when collapsing repeated ticket events into a single change record.
- #5easysometimes asked
5. Remove Element
Remove every occurrence of a target value from an array in place, returning the new length. ServiceNow uses this to confirm you understand in-place compaction — the same trick they use when purging soft-deleted incident rows from a result buffer.
- #7easysometimes asked
7. Plus One
Given a digit array representing a non-negative integer, return the array after adding one. ServiceNow uses this to test carry-propagation hygiene — the same shape they apply when incrementing record version counters in their CMDB.
- #8easysometimes asked
8. Merge Sorted Array
Merge nums2 into nums1 (which has trailing zero slots) so that nums1 stays sorted, in place. ServiceNow uses this to test the back-to-front three-pointer trick — the same shape they apply when blending two priority queues without an auxiliary buffer.
- #9easysometimes asked
9. Binary Tree Inorder Traversal
Return the inorder traversal of a binary tree's node values. ServiceNow asks this to confirm recursion fluency and to see if you can write the iterative stack-based version — the same trick they use when walking approval-chain trees in their workflow engine.
- #10easysometimes asked
10. Same Tree
Given two binary trees, decide whether they are structurally identical and have equal values. ServiceNow asks this to verify recursive tree equality fluency — the same shape they apply when diffing two snapshots of a workflow definition.
- #11easysometimes asked
11. Symmetric Tree
Given the root of a binary tree, check whether it is a mirror of itself. ServiceNow asks this to confirm you can write a paired recursion (compare left.left with right.right, left.right with right.left) — useful in any mirrored workflow validation.
- #13easysometimes asked
13. Path Sum
Determine if a binary tree has a root-to-leaf path whose node values sum to a target. ServiceNow favors this to test recursive tree traversal under a constraint, which mirrors how their workflow engine evaluates cumulative cost thresholds in approval chains.
- #14easysometimes asked
14. Pascal's Triangle
Generate the first numRows of Pascal's triangle. ServiceNow uses this to verify candidates can build and index 2-D arrays correctly — a skill directly relevant to their report-grid and matrix-based workflow analytics features.
- #15easysometimes asked
15. Single Number
Find the one element in an array that appears exactly once when all others appear twice. ServiceNow uses this to test bit-manipulation awareness and O(1)-space thinking — skills that surface when candidates discuss efficient event-deduplication in high-volume incident streams.