Medium eBay Interview Questions: Strategy Guide

Medium questions at eBay typically focus on practical problem-solving with clean, efficient code. They test your ability to handle real-world data structures and algorithms under interview constraints, often with a slant toward scenarios involving transactions, listings, or data streams. Expect problems on arrays, strings, trees, and graphs that require a solid grasp of core patterns.

Common Patterns

eBay's Medium problems frequently test these algorithmic patterns. Mastery here is key.

Two Pointers & Sliding Window: Used for array/string manipulation, finding subarrays, or deduplication.

def max_subarray_sum(nums, k):
    window_sum = sum(nums[:k])
    max_sum = window_sum
    for i in range(k, len(nums)):
        window_sum += nums[i] - nums[i - k]
        max_sum = max(max_sum, window_sum)
    return max_sum

Tree & Graph Traversal: BFS and DFS appear often, especially for hierarchical or relational data.

def dfs(node, target):
    if not node:
        return False
    if node.val == target:
        return True
    return dfs(node.left, target) or dfs(node.right, target)

Hash Maps for Frequency/Index Tracking: Essential for problems involving anagrams, pairs, or caching.

Time Targets

Aim to solve a Medium problem within 25-30 minutes in an interview setting. Break this down: spend 5-7 minutes understanding the problem and discussing edge cases, 10-12 minutes writing the initial solution, and 5-8 minutes testing and optimizing. If you hit 20 minutes without a working approach, state your current reasoning and ask for a hint. Efficiency matters more than raw speed—clear logic and communication are critical.

Practice Strategy

Don't just solve problems; simulate the interview. For each of eBay's 38 Medium questions:

1. Timebox strictly: Use a 30-minute timer.
2. Verbally articulate your steps: Explain your reasoning as you would to an interviewer.
3. Write production-ready code: Include meaningful variable names and handle edge cases.
4. Review optimal solutions: If your initial solution isn't optimal, analyze the gap and re-solve the problem the next day. Focus on the patterns above, as they form the core of eBay's question set. Quality repetition beats quantity.

Practice Medium eBay questions