Array Questions at Tekion: What to Expect

Array questions dominate Tekion's technical interviews, making up 18 of their 23 most frequently asked problems. This heavy focus isn't an accident. Tekion builds cloud platforms for the automotive industry, which involves processing large streams of real-time data—vehicle telemetry, inventory lists, customer records, and transaction logs. These data sets are fundamentally sequential and indexable, making arrays the core structure for manipulation, transformation, and analysis in their systems. Mastering array algorithms demonstrates your ability to handle the foundational data flows at the heart of their products. If you're interviewing at Tekion, consider array proficiency non-negotiable.

What to Expect — Types of Problems

The array problems at Tekion test a blend of fundamental logic and practical application. You can expect three primary categories:

1. In-Place Array Manipulation: Problems requiring you to modify the array without using extra space, such as moving zeros, removing duplicates from a sorted array, or applying rotations. These test your understanding of two-pointer techniques and careful index management.
2. Subarray & Prefix Sum Analysis: Questions involving finding subarrays that meet a sum or product condition, or calculating ranges efficiently. These assess your ability to optimize beyond brute-force O(n²) solutions using hashing or sliding windows.
3. Sorting & Searching Variants: While not always pure "sort an array" tasks, many problems build on sorted array logic. Expect challenges like finding a missing number, a duplicate, or the minimum in a rotated sorted array, which require modified binary search.

The problems often have a "practical" feel, mirroring data processing tasks you might encounter on the job, rather than purely abstract algorithm puzzles.

How to Prepare — Study Tips with One Code Example

Your preparation should be systematic. First, ensure you have absolute mastery over the two-pointer technique (for in-place operations and sorted arrays) and the sliding window/hash map pattern (for subarray problems). Practice drawing out the array and pointer movements on a whiteboard. Always discuss edge cases—empty arrays, single elements, all identical elements, or maximum-size inputs.

A critical pattern is the "Two-Pointer for In-Place Swaps or Fills," commonly used for problems like moving zeros or removing elements. The key is to use one pointer (write or insertPos) to track the position for the next valid element and another (current) to scan through the array.

def moveZeroes(nums):
    """
    Moves all zeros to the end in-place.
    """
    insert_pos = 0  # Tracks position for next non-zero element

    for current in range(len(nums)):
        if nums[current] != 0:
            nums[insert_pos], nums[current] = nums[current], nums[insert_pos]
            insert_pos += 1
    # No explicit return needed; modifying in-place

Recommended Practice Order

Tackle the problems in order of increasing conceptual complexity to build confidence:

1. Start with basic in-place operations (Remove Duplicates from Sorted Array, Move Zeroes).
2. Move to two-pointer problems on sorted arrays (Two Sum II, 3Sum).
3. Then tackle sliding window and prefix sum problems (Maximum Subarray, Subarray Sum Equals K).
4. Finally, practice the tricky search variants (Find Minimum in Rotated Sorted Array, Search in Rotated Sorted Array).

For each problem, time yourself, write clean code on the first try, and verbalize your reasoning as if in an interview.

Practice Array at Tekion