Uber Software Engineer Interview Guide

The Phone screen is a 45-minute telephonic interview with the recruiter. Here, the recruiter asks questions related to your CV and work experience, if any. The basic aim of this exercise is to test the candidate's motivation for the role and to know if he/she meets the experiential and cultural fit for the role and the company. Candidates who are fresh out of college should be thorough with their CV, and any projects or internships they might have done while at college.

Most asked interview questions in the Phone Screen.

• Why do you want to pursue a career in software engineering?
• Why Uber?

The technical screen is a one-hour interview with the hiring manager and an Uber software engineer. This round is aimed at assessing your technical skills in the following areas:

• Coding Aptitude
• Systems Design
• Algorithms and Data Structures

Coding Aptitude 

The coding aptitude section of the technical screen will feature questions that test the general programming abilities of the candidate. The focus will primarily be on object-oriented programming. Students need to be proficient in at least one of the programming languages among C++, Java, and Python. Candidates who are good at all these programming languages will be in a better position as compared to other candidates. Candidates are asked 2-3 questions that need to be attempted through an online shared code editor.

Most commonly asked Coding questions in the Technical screen:

• Given an array of integers, return a new array such that each element at index i of the new array is the product of all the numbers in the original array except the one at i.
• Given a sorted array a[ ] and a number p, write a function that counts the occurrences of p in a[ ].
• Write a code to add an element in the middle of a linked list.
• Can you write a function to convert a sorted list into a binary search tree?

System Design

Systems design is the process of defining the architecture, product design, modules, interfaces, and data for a system to satisfy specified requirements. Companies such as Uber need candidates with good system design abilities to help them solve real problems that they might be facing through the tangible application of knowledge.

Most commonly asked System Design questions

• Explain the design elements of a search engine.
• Tell us your approach to designing a web crawler. When should it be used?
• Design a recommendation system?
• How would you design a garbage collection system?
• Tell me how you would design a chat application like Whatsapp or Facebook messenger?

Algorithm and data structures 

Data structure is a fundamental concept of any programming language, essential for algorithmic design. It is used for the efficient organization and modification of data.

Most commonly asked algorithm and data structures questions

• What is the requirement for an object to be used as a key or value in HashMap?
• Given an integer n, write a function to compute the nth Fibonacci number.
• Write an algorithm to remove duplicates from a given array in Java?
• Write an algorithm to find all pairs of an integer array whose sum is equal to a given number?

The onsite round is an extended version of the phone screen. It is conducted at one of  Uber's campuses and consists of 5-6 interviews covering various sections like:

• Data structures and algorithm
• Database management
• System design
• Coding aptitude
• Behavioural aptitude

Each of the 5-6 interviews in the onsite round is 1-hour long. Questions in the onsite round are more in-depth as compared to the technical screen. In addition to the 4 interview topics covered in the technical screen, the onsite round features an additional interview on behavioural aptitude.

Data structures and algorithm

The questions here will involve the application of data structures concepts, such as arrays, linked list, stack, queue etc to write algorithms.

Most commonly asked Data Structures and Algorithm question in the onsite round

• Write an algorithm to find the sum of two linked lists using Stack.
• Write an algorithm to print all nodes of a given binary tree using inorder traversal without recursion.
• Write an algorithm to swap two numbers without using the third variable.

Database Management

Database management refers to the process of manipulation and control of data by companies to meet necessary conditions throughout the entire data lifecycle of a project or software system. Uber focuses on assessing a candidate's database management skills, especially their SQL abilities.

Most commonly asked database management questions in the onsite round

• Describe BLOB in MySQL. What is it used for?
• State the difference between VARCHAR and CHAR. Give examples of cases where you would prefer using one over the other.
• Differentiate between Data Definition Language (DDL) and Data Manipulation Language (DML).
• In MySQL, where are FEDERATED tables used?

System Design

In the course of their role of building software and systems, software engineers often run into tasks that involve system design.

Here are the most commonly asked System Design questions in the Onsite Round

• Are you aware of URL Shorteners? How would you design a URL Shortening service like goo.gl or bit.ly?
• Design the front end of an online cupcake selling company.
• Suggest 3 changes to Uber's front end design. How would these changes be useful?
• Design an audio streaming service.

Coding Aptitude

Coding is one of the most fundamental skills that software engineers are expected to be good at. Uber expects candidates to be proficient in any or all of  Go, Python, Ruby, Java, and C/C++ programming languages.

Candidates will face 2-3 coding questions in the allotted one hour of the coding interview.

Most commonly asked Coding questions in the onsite round

• You are given a string. Write a function to find all non-single letter substrings that are palindromes.
• Suppose you are given a positive integer, x. Write a code to print all possible combinations of positive integers that add to the number x.
• Write a code to search for a given number in a sorted array, with unique elements, that has been rotated by some arbitrary number. Assume that the array does not have duplicates. Return null if the given number does not exist in the sorted array.

Behavioural 

The Behavioural interview will consist of questions to assess behavioural aspects of your personality. You may be asked situational questions as to how you tackled a particular question. Interviewers may also be interested in knowing what drives you to become a software engineer, or what is your motivation for choosing Uber.

The important thing to keep in mind in behavioural interviews is to speak your mind and be honest in your replies. There is always a possibility of back and forth between you and the interviewers over a question or an answer, so be ready for that.

Most commonly asked questions in the Behavioral section

• Why Uber?
• Why software engineering?
• Where do you see yourself 10 years down the line?

• Follow the "Think out loud" approach to let the interviewers know your approach to the answer, and avoid rushing to answer.
• Do not hesitate to ask clarifying questions.