My Tekion SDE-1 (Backend) Interview Experience

Interviewing at Tekion for the SDE-1 (Backend) position was a memorable learning journey. The overall interview process gave me valuable insights into how Tekion evaluates candidates both technically and behaviorally.

In this blog, I will walk you through the entire interview process, including question types, coding problems, design discussions and key preparation tips for future candidates. Here, I have also included all the interview questions that were asked during my interviews.

Round 1: Online Assessment (Coding)

• Difficulty: Medium
• Duration: 60 minutes
• Mode: Remote

The process began with an online assessment consisting of three algorithmic problems designed to test problem-solving skills and data structure fundamentals.

Problem 1: Minimum Cost Path in a Grid

• Type: Dynamic Programming

Find the minimum cost to move from the top-left to the bottom-right corner of a grid, navigating around obstacles. You could only move right or down and each cell had an associated cost.

My Approach:

• I implemented a DP table to store the minimum cost at each cell, using the formula:

dp[i][j] = cost[i][j] + min(dp[i-1][j], dp[i][j-1])

• This ensured an optimal solution with O(n²) complexity.

Problem 2: Length of the Longest Arithmetic Progression

• Type: Dynamic Programming + Hash Map

Given an array, find the length of the longest arithmetic progression (AP) that can be formed from its elements.

My Approach:

• I sorted the array and used a hash map of differences to keep track of AP lengths dynamically.
• For every pair (i, j), I calculated the difference diff = arr[j] - arr[i] and updated dp[j][diff] = dp[i][diff] + 1.

Problem 3: Minimum Number of Stops to Reach Target

• Type: Greedy Algorithm

You are given a target distance and a list of fuel stations. Find the minimum number of stops required to reach the target, assuming you start with a certain amount of fuel.

My Approach:

• I used a max-heap to keep track of the best refueling options as I moved forward.
• While my solution worked, I felt there was room for space optimization.

Result: I managed to solve all three problems successfully, though I noted that my third solution could have been optimized further.

Round 2: DSA + Logical Thinking

• Difficulty: Medium
• Duration: 60 minutes
• Mode: Remote

This round was focused entirely on Data Structures and Algorithms. The interviewer tested my analytical reasoning and efficiency in solving classical DSA problems.

Problem 1: 8-Ball Weighing Puzzle

Out of 8 identical-looking balls, one is heavier. You can use a balance scale only 3 times to find the heavier ball.

My Approach:

• I applied a divide-and-conquer strategy, dividing the balls into three groups to minimize comparisons.
• After each weighing, I reduced the search space by one-third until the heavier ball was identified.

Problem 2: Product of Array Except Self

Given an array nums, return an array where each element is the product of all other elements except itself without using division.

My Approach:

• I computed two auxiliary arrays:

  • Prefix product: product of all elements before the current index.

  • Suffix product: product of all elements after the current index.

• Then combined them to get the final answer in O(n) time and O(1) extra space.

Result: The discussion went smoothly, the interviewer appreciated my step-by-step explanation and dry runs.

Round 3: Low-Level Design (LLD)

• Difficulty: Medium
• Duration: 60 minutes
• Mode: Remote

This round tested my object-oriented design skills, Java fundamentals and ability to design scalable systems.

Discussion Topics:

• Past project architecture : design decisions, scalability and patterns used.

• Java + Mockito: detailed discussion on mocking, dependency injection and unit testing using TDD.

Design Problem: Elevator System

Design an elevator system for a multi-floor building that efficiently handles multiple requests.

Key Considerations:

• Elevator scheduling (up/down requests)

• Prioritization logic

• Handling multiple elevators

Modular class design for extensibility

I designed the system using OOP principles, defining classes like Elevator, Request and Scheduler. Focused on clean modular design, thread-safe request handling and optimized scheduling algorithms. The interviewer appreciated my detailed approach and design clarity.

Round 4: Hiring Manager (HM) Discussion

• Difficulty: Medium
• Duration: 60 minutes
• Mode: Remote

This round combined technical and behavioral evaluation. The hiring manager assessed not only my technical depth but also my problem-solving attitude and team communication style.

Technical Topics:

Java Concurrency: Discussion around threads, synchronization and common pitfalls like race conditions and deadlocks. I explained how I used synchronization blocks and thread-safe collections in past projects.

Behavioral Questions:

• Tell me about a time when you disagreed with your team on a technical decision.

• How do you manage tight deadlines while maintaining code quality?

• What's your approach when handling production issues under pressure?

These questions aimed to evaluate my collaboration, communication and decision-making abilities in real-world situations.

Preparation Tips for Future Candidates

If you're preparing for Tekion's SDE-1 (Backend) interview or similar roles, here's what I'd recommend:

• Master DSA fundamentals : Arrays, Linked Lists, Trees and Dynamic Programming.

• Focus on Java concepts : Concurrency, Collections, OOP principles and Exception handling.

• Practice System Design : Start with Elevator System, Cache Systems and Request Schedulers.

• Work on communication : Clear explanation and structured thinking go a long way.

• Mock interviews : Practice with peers or mentors to refine your articulation and timing.