Uber Android Engineer Interview

The Recruiter Introduction Chat at Uber is a 30-minute session where they aim to build a connection and grasp your background. The recruiter, known for being helpful and friendly, typically delves into behavioural and get-to-know-you questions. So, this includes enquiries like “Can you share a bit about your professional background and what led you to Android development?”

Don't be surprised if they throw in some basic technical questions; those are also reportedly common. If you do well in this round, the recruiter will schedule a virtual phone screen with an Android Engineer at Uber.

The second round of the Uber Android Engineer Interview, conducted virtually for one hour, primarily focuses on assessing your coding skills and problem-solving abilities. During this phase, you can expect to be presented with LeetCode-style coding questions, often falling into the Easy to Medium difficulty range. For instance, Implement a HashMap.

Overall, it's an interactive session designed to assess how you work in a collaborative environment. So, don't hesitate to ask questions and use the opportunity to articulate your thought process. The emphasis is not just on presenting a correct solution but also on your ability to approach problems, communicate your reasoning, and adapt to different scenarios.

Interview Questions:

• Implement a function to reverse a singly linked list.
• Find the length of the longest substring without repeating characters in a given string.
• Given a binary tree, return the level order traversal of its nodes' values.
• Given a collection of intervals, merge overlapping intervals.
• Given n non-negative integers representing the histogram's bar height, find the area of the largest rectangle in the histogram.

Once you've successfully completed the virtual screening, you'll be invited on-site for an additional five rounds of interviews at Uber's premises. These include:

1. Walk-in with Recruiter (15 mins)
2. In-depth Android Coding (1 Hour)
3. HM Chat (1 Hour)
4. System Design and Architecture (1 Hour)
5. Coding Round (1 Hour)
   

Walk-in with Recruiter

The Walk-in with the Recruiter lasts about 15 minutes and is a straightforward session serving as a general walkthrough of what a day at Uber typically looks like for employees. The recruiter is open to any questions you may have, whether they pertain to Uber, the company culture, details about upcoming rounds, or any specific inquiries you might have. 

It's a great opportunity to set the tone for the day and gather valuable insights before diving into the subsequent interviews. 

In-depth Android Coding

So, this is essentially the first round which revolves around your role as an Android engineer.  It spans a duration of one hour, during which you're provided with a sample project in a .zip file. Your task is to open it in Android Studio and integrate a specified feature, adding a practical, hands-on element to the assessment. 

Another common question is “Given a restCall with cities/countries, populate a recyclerview to match a given design.”

So, this might seem like a simple, straightforward round but it can be complicated. Why? Because the sample code provided might be outdated or poorly written, potentially lacking any recognizable architecture. Additionally, REST calls will typically be mocked, and you'll need to find the best way to use functions in a big mess of code.

Here's a tip: Focus on making things work rather than making your code perfect. Since you get the problem on the spot, be ready to adapt. Ask questions and collaborate with your interviewers. And explain your steps out loud throughout so they know you are aware of the technical components that go behind Android development. This approach is akin to the hands-on coding assessments for Meta iOS Engineers, where practical coding and problem-solving skills are evaluated.

HM Chat

During the HM Chat, you engage with a hiring manager for an hour where you delve into behavioural questions and past experiences. For instance,

• Tell me about the most difficult challenge you've faced and how did you overcome it? Or 
• Have you ever had to deal with a difficult coworker?
• Have you been responsible for improvements made to the DevOps process in your team?
  

Here, you will need to bring up examples of past projects to effectively answer these questions. Highlight your interpersonal and problem-solving using real-world scenarios from your professional history. This will make your claims more impactful. 

After the HM chat, you'll have a 1 hour lunch break prior to the challenging Design and Architecture round. This is a chance to catch up with Uber employees and learn more about the internal day-to-day operations at Uber.

System Design and Architecture Round

In the System Design and Architecture Round (Round 4), you'll have a 1-hour session where the first 30 minutes are dedicated to discussing the design of a project you're familiar with, preferably one you've contributed to. 

The remaining 30 minutes involve the interviewer presenting a new problem for you to design and architect. You'll be tasked with designing the architecture for a complete Android product or feature.

This round is not about writing code; it's more like a chat where you use a virtual whiteboard. You might draw diagrams or explain how things should work. 

Preparing for this interview might be a bit tricky because it's very interactive, and there's no one "right answer" for design problems. Here are some tips to help you get ready:

• If the interviewer asks a broad question like "How would you design the front-end for a messaging system?" don't panic. It's your job to guide the discussion. They want to know how well you can solve a challenging engineering design problem, and if you can come up with a solution for a big problem that involves connecting different ideas. So, begin with asking clarifying questions, as many as needed, to gather the details you need to come up with a solution. For instance,
• How many users are we talking about?
• What should the waiting experience be like?
• What are the speed requirements for messages?
• What features do we need?
• Then move smoothly from big-picture ideas to specific details. Describe what components you'd need, how they fit together, and how you'd solve the problem. It's a good exercise to think about how you'd create complicated, large-scale systems, for instance, a system for a big tech company like Uber. Or you might think about designs you've already made. Consider what worked well and what didn't. Look at different solutions and talk about the good and bad parts of each. Show that you can make smart choices about balancing these tradeoffs. 
• Show them that you know basic Android parts like Activities, Views, Fragments, and Services. Also, use your experience to explain how more advanced parts might work. And design everything that happens on the phone. You don't need to go too much in depth — just say which server tools you'd use. Make sure to factor in phone limitations like battery, bandwidth usage, and storage. Explain how you'd handle tasks happening in the background.
• Lastly, try to get some interview-like practice and insights into what it's really like to interview for this round. You can seek help from an Android engineer at Uber; they can provide valuable guidance and even provide feedback to help refine your answers. You can connect with an Android Engineer at Uber via Prepfully here—book a practice session directly.

Coding Round (Algorithms & Data Structures)

The Coding Round (Algorithms & Data Structures) is quite similar to the Virtual phone screen round. You'll be given coding problems from platforms like LeetCode—you'll need to code in Kotlin, Java, or C++. 

The key here is to show how you think through problems and write your code. Explain your steps as you go, and don't stress about small errors since they won't compile your code.

Practise different types of problem-solving techniques like sorting and recursion. Also, make sure you're comfortable with common data structures like arrays, stacks, hash tables, trees, and graphs. This will help you handle the challenges thrown at you in this interview.
Check out the Facebook Network Engineer and Tinder iOS Engineer guides for additional insights.

Interview Questions

• Implementing HashMap
• Design the system for a board game
• Performing binary search with duplicate values
• Tell me about a difficult challenge you've faced and how you handled it
• Design an Elevator system, considering yourself as an elevator company. Include only classes and interfaces. The system should handle multiple elevators in a building, with each elevator servicing only a subset of floors.
• Design a system to implement two functions: add(int val) and query(int val). The query(int val) function should return the largest value less than or equal to the input.