My Uber SDE-1 Interview Experience

Cracking an interview at Uber is a dream for many software developers. I recently had the opportunity to participate in the Uber SDE-1 placement. Although I didn't make it to the final round, the experience taught me a lot about where I stood, how Uber evaluates candidates and what to improve for the future. Here's my complete Uber interview experience with interview questions.

Application Journey

I applied for Uber through uber carrer.

Even though I couldn't clear all rounds, I consider this interview a valuable experience to assess my strengths and weaknesses. It showed me exactly what I needed to improve for future interviews.

Round 1 : Online Coding Round (Easy)

• Duration: 90 Minutes
• Platform: Online Coding Platform
• Format: 12 Questions -> 10 MCQs + 2 Coding Problems

This was a moderate-level test. With a decent command of Linux, DSA and basic programming, you can comfortably crack it.

Coding Problems:

1. Longest Common Subsequence

• Difficulty: Moderate

Given two strings, find the length of their longest subsequence that appears in both strings (not necessarily contiguous).

Input: s1 = "abcde", s2 = "ace"
Output: 3
Explanation: LCS is "ace"

My Approach:

• Recognized it as a Dynamic Programming problem.

• Created a 2D DP array (dp[i][j]) to store intermediate results.

• The answer was found at the bottom-right cell of the DP matrix.

2. Rearrange Linked List

• Difficulty: Moderate

Reorder a singly linked list such that all nodes from the second half are reversed and merged alternately with nodes from the first half.

Input: 1 -> 2 -> 3 -> 4 -> 5
Output: 1 -> 5 -> 2 -> 4 -> 3

Concepts: Linked List Manipulation, Reversal, Two-Pointer

My Approach:

• Find the middle of the linked list.

• Reverse the second half.

• Merge both halves alternately.

Round 2 : Technical Round (Medium)

• Duration: 60 Minutes
• Format: 2 Problems + Conceptual Questions

This round tested both data structure understanding and database knowledge.

Coding Problems:

1. Deletion in Doubly Linked List

• Difficulty: Easy

Delete a given node from a doubly linked list while maintaining proper link connections.

My Approach:

• Update the next of the previous node and the prev of the next node to skip the target node.

• Handle edge cases for head or tail deletion.

Interviewer wants to understood my knowledge on node connections and pointer adjustments. Interviewer also discussed self-balancing tree concepts related to efficient data management.

2. SQL Question

Problem:

Write a query to find the student with the second-highest marks.

My Approach:

• Used a nested query to exclude the maximum and then find the next maximum.

SELECT MAX(marks)
FROM students
WHERE marks < (SELECT MAX(marks) FROM students);

Round 3 : System Design

• Duration: 60 Minutes

1. System Design : Online Food Delivery System (Moderate)

Design a scalable food delivery platform like Uber Eats or DoorDash that supports user interaction, order management, delivery tracking and payments.

Key Considerations:

• Users: Customers, Restaurants and Delivery Partners

• Features: Search restaurants, place orders, real-time delivery tracking and secure payments

• API flow and user interface considerations

• Real-time updates for tracking

Database Design:

• Tables for Users, Orders, Restaurants, Menus and Deliveries

Scalability:

• Use caching, load balancers and a microservices-based architecture