SoFi Coding Interview Questions
25 SoFi coding interview problems with full optimal solutions — 13 easy, 10 medium, 2 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an SoFi interviewer values, and a FAQ section.
Showing 13 problems of 25
- #1easyfoundational
1. Two Sum
Find two indices whose values sum to a target — a hash-map warmup SoFi uses to gauge baseline fluency before loan-calculation rounds.
- #2easyfoundational
2. Valid Parentheses
Validate bracket matching using a stack — SoFi uses this to gauge fluency with stack-based parsers for transaction-rule strings.
- #3easyfoundational
3. Merge Two Sorted Lists
Merge two sorted linked lists — SoFi maps this to merging two sorted streams of loan-payment events.
- #4easyfoundational
4. Remove Duplicates from Sorted Array
Dedupe a sorted array in-place — SoFi uses this as a stand-in for deduping repeated loan-disbursement records.
- #5easyfoundational
5. Remove Element
In-place removal of a target value — at SoFi this becomes filtering reversed transactions from a payment batch.
- #6easyfoundational
6. Search Insert Position
Binary search for the insertion point of a value — SoFi uses this to gauge fluency with sorted-array lookups in their loan-amortization tables.
- #7easyfoundational
7. Maximum Subarray
Find the contiguous subarray with the largest sum — SoFi frames this as finding the best contiguous return window in a portfolio's daily PnL series.
- #8easyfoundational
8. Plus One
Increment a number stored as a digit array — SoFi uses this as a warmup for big-integer arithmetic that appears in their interest-precision code.
- #9easyfoundational
9. Same Tree
Given two binary trees, check if they are structurally identical with the same node values — a recursion warm-up SoFi uses when modeling account hierarchy comparison.
- #10easyfoundational
10. Symmetric Tree
Determine if a binary tree is a mirror of itself — SoFi uses this to gauge tree-recursion intuition before scaling up to portfolio-balance trees.
- #11easyfoundational
11. Maximum Depth of Binary Tree
Return the height of a binary tree — SoFi uses this as a starter to verify candidates can write clean DFS, since loan-portfolio risk trees can grow deep across guarantor chains.
- #12easyfoundational
12. Pascal's Triangle
Generate the first numRows of Pascal's triangle — SoFi uses this to test whether candidates can derive each row from the previous, a pattern that mirrors compounding interest schedules.
- #13easyfoundational
13. Single Number
Find the element that appears exactly once when every other element appears twice — a classic O(1) space problem SoFi uses to filter out brute-forcers.