Uber continues to make strides in innovative solutions, with their foray into Generative AI for mobile testing in April 2024 being the latest example. To continue driving creative change, Uber requires machine learning engineers with a talent for solving complex logistical problems. The company offers competitive salaries and benefits, making it an attractive workplace if you want to enhance your skills and advance your career in machine learning.
This guide provides a detailed overview of the interview process at Uber. It includes commonly asked Uber Machine Learning Engineer interview questions and practical tips to boost your chances of securing the position.
Getting ready for an Machine Learning Engineer interview at Uber? The Uber Machine Learning Engineer interview span across 10 to 12 different question topics. In preparing for the interview:
Interview Query regularly analyzes interview experience data, and we've used that data to produce this guide, with sample interview questions and an overview of the Uber Machine Learning Engineer interview.
The Uber machine learning interview is a highly structured process with a rubric of skill sets on which you’ll be graded. This role requires deep knowledge of programming and machine learning algorithms. You can expect nuanced discussions around algorithms and their applications, so we recommend you take a few weeks to review supervised, unsupervised, semi-supervised, and reinforcement learning algorithms.
In addition to theoretical concepts, the interviewers will test your business sense, i.e., how well you apply concepts in real-world optimization scenarios. Look at the job description to understand the problems the team is solving.
Some of the challenges are data sparsity, delay in realizing the impact of actions, network effects, long-term behavioral changes in the driver community, and geo differences in driver values and Uber business. Because of the open-ended nature of these challenges, you can expect challenging case study problems in the Uber interview.
On a related note, check out our guide on preparing a solid interview strategy, or read about this ML engineer’s inspiring journey here if you’re stuck.
The process generally concludes in a month or so.
After you apply online, a recruiter will contact you to have an informal discussion about the role and team, your willingness to relocate, and your salary expectations.
A hiring manager will contact you to learn more about your work experience and cultural fit. At this stage, you may also be asked some high-level technical questions. Prepare some responses and study your past projects.
Common questions asked in this stage:
This round is sometimes skipped, but candidates are usually given a 75-minute coding test consisting of four questions at the medium-to-hard Leetcode level. Dynamic programming is the main skill that is tested. Some common problems that are given are:
You will then be invited to a series of technical interviews over video calls and in person. There may be up to 5 or 6 rounds. These are:
Here are some interview tips from Uber’s Careers page:
In this section, we’ll review the various interview questions that might be asked during an Uber machine learning interview.
You can expect a mix of technical and behavioral questions. Technical questions often cover fundamental machine learning concepts, like explaining different ML models, understanding the bias-variance trade-off, and addressing overfitting.
They also include systems design questions (for L5 and above), such as designing a ranking system. For behavioral questions, the interviewers evaluate your alignment with Uber’s values, past projects and conflict resolution, and motivation for joining Uber.
Check out this video on the types of ML engineer interview questions, or read our post on the types of machine learning questions commonly asked.
Uber engineers work closely with technical and non-technical team members. Expect data communication questions to test how well you convey complex technical information.
How to Answer
Focus on a specific instance where you broke down a technical issue for a non-technical audience. Use the STAR method of storytelling. Discuss the Specific situation you were challenged with, the Task you decided on, the Action you took, and the Result of your efforts.
Example
“In my previous role, I was tasked with explaining a complex cloud integration issue to a client unfamiliar with cloud computing. I compared the process to merging different departments within a company, each with its unique processes and data. I made sure to use minimal technical jargon. This helped the client grasp the challenges of the problem.”
Interviewers will want to know why you chose the ML engineer role at Uber. They want to establish whether you’re passionate about the company’s culture and values or your interest is more opportunistic.
How to Answer
Demonstrate knowledge of Uber’s work, culture, and the distinct opportunities that attract you to the company. Be honest and specific about how Uber’s offerings align with your career goals.
Example
“Working at Uber would be a fantastic opportunity to be part of a team that values innovation, promotes learning, and impacts millions of lives daily. I’m intrigued by Uber’s innovative approach to solving real-world transportation challenges, its global impact, and the opportunity to work with diverse teams.”
Given Uber’s focus on diversity and inclusion, the company would want to understand how well-versed you are in avoiding algorithmic prejudices.
How to Answer
Describe an instance where you identified bias in a dataset or analysis process, and highlight the impact of your actions on the project outcomes.
Example
“In a previous project to enhance loan approval algorithms for a fintech company, I looked at historical trends and identified a bias where applicants from certain zip codes were less likely to be approved. We then re-evaluated our data sources and model assumptions to make the approval process more equitable. We did this by incorporating a broader set of financial health indicators and removing zip code as a determinant factor.”
You may need to work across teams, projects, and geographies at Uber. You’ll have to handle dissent and conflict and bring everyone on board with your ideas.
How to Answer
Choose an instance where you faced disagreement over a technical approach. Explain how you opened a dialogue to understand the others’ perspectives, addressed their concerns, and reached a consensus or a productive compromise.
Example
“In my previous role, I proposed using a convolutional neural network (CNN) for an image classification project. My team was concerned about the model’s complexity and resource requirements. During a team meeting, two colleagues proposed using pre-trained models to reduce resource demands. I incorporated their insights, opting for a transfer learning approach with a pre-trained CNN, which addressed the team’s concerns about complexity and resources. This led to a successful pilot, balancing technical robustness with practical efficiency.”
This is an excellent behavioral question as it simultaneously assesses your critical thinking and understanding of Uber’s products and business objectives.
How to Answer
Reflect on your experience with the app, identifying any features or processes that seemed cumbersome or areas where Uber could update their technology for better service. Your answer should show you understand the user’s perspective and can think strategically about product development. Show that you are acquainted with Uber’s business strategy and goals and align your solutions accordingly.
Example
“One area I believe could improve is integrating real-time urban mobility data to optimize route planning for rides and deliveries. For example, incorporating live traffic updates, public transit schedules, and pedestrian flow patterns could enhance the app’s navigational algorithms to help reduce wait times. These improvements would provide more eco-friendly route options by suggesting rideshare opportunities or integrating with public transit options. Learning from the recent redesign that aimed at simplification and personalization, this feature could further personalize the user experience. This could start with a pilot in densely populated cities, using a phased approach to refine algorithms.”
Unsupervised learning algorithms are deployed at Uber to segment customers and analyze trip and location density situations.
How to Answer
Highlight the importance of vectorized operations for efficiency. Mention considerations like the number of clusters and how you would reduce the likelihood of poor clustering.
Example
“The algorithm’s steps are: initializing centroids, assigning data points to clusters, updating centroids, and iterating until convergence. The use of NumPy will allow for efficient vectorized calculations. Array indexing to access data points, np.mean(), and boolean indexing to filter data points by cluster, are some techniques and functions used.”
m x n
integer matrix grid. A rhombus sum is the sum of the elements that form the border of a regular rhombus shape in a grid. The rhombus must have the shape of a square rotated 45 degrees, with each corner centered in a grid cell. Return the biggest three distinct rhombus sums in the grid in descending order. If there are less than three distinct values, return all of them.Matrix manipulation helps Uber engineers analyze spatial data to determine areas of high traffic congestion.
How to Answer
Outline a method to iterate over potential center points of the rhombuses in the matrix while considering valid sizes based on the grid dimensions. Emphasize the need for efficiency in sum calculations.
Example
“I’d start by considering each cell in the matrix as a potential center for a rhombus. I would calculate possible rhombus sizes based on the minimum distance from the center to the grid’s edges. For each size, I’d compute the sum of the border elements by tracing the perimeter of the rhombus. These sums should be stored in a set to maintain the three largest distinct sums efficiently. I’d continue this process for each center and each possible size until all options have been exhausted. This approach will ensure we capture the top three distinct sums while avoiding unnecessary recalculations for different rhombuses.”
drivers
table called weighting
. It contains a weighted value, which they hope will lead to better matching. Given this table of drivers, write a query to perform a weighted random selection of a driver based on driver weight.This type of problem directly relates to Uber’s ability to experiment with features to enhance service quality.
How to Answer
Highlight how you would adjust driver weights to reflect their selection probability, and mention the SQL functions you would employ to achieve this.
Example
“The process involves two key steps: adjusting the drivers’ weights so that they reflect the probability of selection and then picking a driver based on these probabilities. First, I’d calculate the sum of all weights in the drivers’ table to understand each driver’s relative weight. I’d then generate a random number and use it to select a driver by comparing this number to the cumulative distribution of weights. This method ensures that the drivers with higher weights have a proportionally greater chance of being matched.”
nums1
and nums2
of length n, both of which are permutations of [0, 1, …, n - 1]. A good triplet is a set of 3 distinct values that are present in increasing order by position both in nums1
and nums2
. In other words, if we consider pos1v as the index of the value v in nums1
and pos2v as the index of the value v in nums2
, then a good triplet will be a set (x, y, z) where 0 <= x, y, z <= n - 1, such that pos1x < pos1y < pos1z and pos2x < pos2y < pos2z. Return the total number of good triplets.This question tests your ability to solve combinatorial problems that can help optimize matching algorithms.
How to Answer
Explain the approach of first mapping each element’s index from both arrays to facilitate quick lookup. Then discuss iterating over potential triplets in a structured way to minimize unnecessary checks.
Example
“I’d create two dictionaries or arrays to store the indices of each element from both arrays, nums1
and nums2
, which will allow for quick access to any element’s position. Then, we’d iterate through all possible combinations of three distinct numbers (x, y, z) chosen from the set [0, 1, …, n - 1]. For each triplet, I’d use the dictionaries to retrieve the indices of x, y, and z in both nums1
and nums2
. If x, y, and z appear in increasing order in both arrays using these indices, the set is counted as a good triplet. This method ensures that we check valid triplets using indexed lookups, which is much faster than comparing positions repeatedly for each combination.”
pool_matching
that accepts a list of candidates and matches pairs of them based on: 1. scheduled availability and 2. similar interests.Matching based on availability and interests enhances passenger experience and operational efficiency, such as in UberPool.
How to Answer
Break the problem into manageable parts: Sort candidates by availability. Then, group them by interests. Mention the importance of efficient data structures for sorting and matching.
Example
“I would first organize candidates by their available time slots. Then I’d group them by shared interests, using tags or keywords, within each time slot. For each group with similar availability and interests, I’d match pairs or form small groups, prioritizing the closest matches. This process could be implemented using a combination of sorting algorithms and hash maps for efficient matching.”
This tests how nuanced your understanding is of optimization techniques that could be applied to an already well-designed ranking system like Uber Eats.
How to Answer
The expectations for ML design or systems design questions are often unclear and large in scope. So, ask clarifying questions at the outset to define the task outline around model deployment, modeling choices, and business objectives. Mention your plan and the points you wish to touch on at the beginning to minimize interruptions.
Example ”I’d first collect comprehensive data on user behavior and restaurant performance. This would include metrics like user ratings, frequency of orders, cancellation rates, average delivery times, and the diversity of each restaurant’s menu. I’d also incorporate user-specific data such as their previous orders, search habits, and ratings given to similar types of restaurants.
Using this data, I would design a model that predicts user satisfaction with potential restaurant options. I’d include key factors like the restaurant’s proximity to the user, estimated delivery times, price levels, and user-specific dietary preferences.
To align the ranking system with Uber Eats’ business goals, I’d introduce features in the model to promote new restaurants or those offering special promotions so that they gain visibility and traction. I’d implement A/B testing to continuously compare the effectiveness of different ranking algorithms and make adjustments to improve user satisfaction and business outcomes.”
min_distance
to calculate the minimum absolute distance between two elements, then return all pairs having that absolute difference.Uber engineers often need to optimize algorithms, and this question tests this skill in Python.
How to Answer
Explain the approach of first sorting the array to make the comparison of distances between consecutive elements straightforward. Discuss how you would identify the minimum distance by scanning consecutive elements and iterating to gather all pairs that exhibit this minimum distance.
Example
“I would start by sorting the array of integers, as this helps in reducing the complexity of finding the minimum distance. I’d then go through the list to find the minimum absolute difference between each pair of consecutive elements. Once I’ve identified this minimum distance, I’d make a second pass through the array to collect all pairs that have this exact distance. This approach ensures efficiency by reducing the problem to essentially two linear scans of the array.”
tickets
where tickets[i] = [fromi, toi]
represent the departure and the arrival airports of one flight. Reconstruct the itinerary in order and return it. All of the tickets belong to a man who departs from "JFK"
, thus, the itinerary must begin with "JFK"
. If there are multiple valid itineraries, you should return the itinerary that has the smallest lexical order when read as a single string. For example, the itinerary ["JFK", "LGA"]
has a smaller lexical order than ["JFK", "LGB"]
. You may assume all tickets form at least one valid itinerary. You must use all the tickets once and only once.This problem tests your skills in graph theory and algorithm design.
How to Answer
Explain using a depth-first search (DFS) strategy to traverse this graph from “JFK,” sorting the destinations at each node to ensure the smallest order path is considered first.
Example
“I would begin by constructing a graph where each airport is a node, and each ticket is a directed edge from the departure to the arrival airport. Given that the itinerary must start at “JFK” and proceed in the smallest lexical order, I’d sort the adjacency lists of each node lexicographically. I’d then implement a depth-first search starting from “JFK,” continuously choosing the next airport in lexicographical order from the current airport’s adjacency list. This would allow me to follow the smallest available path first.”
This question checks your understanding of ensemble methods and your ability to choose the appropriate algorithm based on a project’s needs.
How to Answer
Highlight the key differences and provide relevant examples of when you would employ each method.
Resource: You can read more on the types of algorithm questions asked in ML engineer interviews.
Example
“Bagging, like in a random forest, is robust against overfitting and works well with complex datasets. However, it might not perform as well when the underlying model is overly simple. Boosting, exemplified by algorithms like XGBoost, often achieves higher accuracy but can be prone to overfitting, especially with noisy data. It’s also typically more computationally intensive.”
A core challenge for Uber is balancing profitability with customer satisfaction; pricing analytics is, therefore, a key skill set that the company values.
How to Answer
Outline a framework incorporating multiple factors: distance, demand-supply balance, time of day, special events, and operational costs. Highlight data analysis to predict demand patterns and adjust prices in real time.
Example
“I’d first introduce a base fare considering distance, time, and base operational costs. I’d incorporate a dynamic component adjusting for real-time demand and supply; for example, prices could increase in areas with high demand but low driver availability. I’d also factor in time-of-day variations, with peak hours having higher rates. Special circumstances like holidays or large local events would also trigger adjustments. Importantly, the model would be transparent to users, explaining why prices might be higher at certain times.
To refine pricing, I’d analyze historical data to identify demand patterns, continuously updating the model to reflect real-world behaviors and preferences.”
This question gauges your ability to apply data science principles to real-world challenges that Uber faces, like how to dynamically balance supply and demand.
How to Answer
Outline a strategy that involves analyzing historical data to identify demand patterns, setting clear objectives for the incentive scheme, and considering both short-term and long-term incentives. Discuss how you’d measure the scheme’s success.
Example
“I’d start by looking at Uber’s historical data to identify when and where demand peaks typically occur. I’d then propose dynamic incentives that increase earnings for trips into these high-demand areas. These incentives could be structured as additional per-trip bonuses, higher rates during certain hours, or rewards for completing a set number of rides in the targeted areas within a specific timeframe. It’s also important to communicate clearly with drivers so they understand the benefits of participating.
Moreover, I’d monitor the effectiveness of this scheme through KPIs such as the number of drivers in high-demand areas during targeted times, customer wait times, and overall customer and driver satisfaction. Based on these metrics, adjustments to the incentives might be necessary to ensure we’re meeting our target of balancing supply and demand properly.”
In machine learning projects, you need to understand this crucial trade-off to reconcile your technical knowledge with your domain expertise, for example, in a customer churn prediction problem.
How to Answer
Define bias and variance in the context of machine learning. Explain the trade-offs, emphasizing the impact of underfitting (high bias) and overfitting (high variance) on model performance. Discuss your recommended strategies to find the optimal balance.
Example
“Bias represents the error introduced by overly simplistic assumptions in a model. When a model exhibits high bias, it tends to oversimplify the problem and underfit the data. On the other hand, variance represents the error due to excessive model complexity, causing the model to fit the training data too closely. Techniques like cross-validation to assess model performance, regularization to control complexity, and thoughtful algorithm selection will help us assess the required trade-off in a specific scenario.”
Predictive modeling is essential for Uber to estimate ride demand and price optimization. This question tests your knowledge of which model would yield the most reliable results.
How to Answer
Compare the features of linear and random forest regression, considering diverse and non-linear determinants, and justify the choice of the model. Explain why one might be more suitable than the other based on the nature of ride demand data.
Example ”I would choose random forest regression over linear regression for predicting ride demand. This is because of the complex nature of ride demand data, which includes non-linear relationships between variables such as time of day, weather conditions, local events, and other factors. Random forest can handle these complexities well because it doesn’t require explicit assumptions about the form of the data. Further, random forest regression provides features like automatic handling of missing values and the ability to rank the importance of different predictors.”
This question assesses your understanding of predictive modeling in a real-world operational context.
How to Answer
You could suggest a regression model since the target variable is continuous. Discuss the selection of features that could influence preparation time.
Example
“I’d opt for a regression model since the output we’re predicting—time—is a continuous variable. Key features to include would be the number and type of items in the order to account for complexity, the time of day and day of the week to reflect the restaurant’s busyness, historical preparation times for similar orders, and even the weather or special events, as these affect demand. Random forest or gradient boosting could be particularly effective due to their ability to handle non-linear relationships and interactions between features.”
This question tests your understanding of dimensionality reduction and clustering techniques and how they can be used together to enhance data analysis. It’s relevant for data science roles at Uber, where you’ll analyze complex datasets to optimize operations and targeting.
How to Answer
Discuss the conceptual link between PCA and K-means clustering, emphasizing PCA’s role in reducing dimensionality for more efficient and potentially more accurate clustering by K-means.
Example
“PCA and K-means clustering are often used together in data preprocessing. PCA reduces dimensionality by transforming data into a set of linearly uncorrelated components that retain most of the variations. This simplification can be helpful before applying K-means clustering, as it makes the clustering process more efficient. By focusing on the principal components, K-means has to deal with less noise and fewer irrelevant dimensions, which can lead to more meaningful clusters.”
In an Uber Machine Learning Engineer interview, this question about the assumptions of linear regression might be asked to assess your understanding of foundational statistical concepts that are critical when building and interpreting predictive models.
How to Answer
There are several assumptions of linear regression. These assumptions are baked into the dataset and how the model is built. Otherwise if these assumptions are violated, we become privy to the phrase “garbage in, garbage out”.
Example
“In linear regression, we assume a linear relationship between the features and the response variable, meaning changes in the input should result in proportional changes in the output. For example, if we’re predicting home prices, the value should increase predictably as the size of the home increases, assuming all else is constant. We also assume additivity, where the effect of one feature on the outcome should not depend on another feature, ensuring that factors like size and location influence home prices independently and consistently.
Additionally, we need to avoid multicollinearity, ensuring that features aren’t too closely related, so we can distinguish their individual effects on the response variable. Lastly, the errors in the regression should be independent and normally distributed, ensuring the model’s predictions are unbiased and that no single feature has an undue influence on the outcome.”
This question tests your ability to think critically about how to efficiently generate all possible combinations that meet a specific criterion, which is crucial in optimizing algorithms and handling large datasets.
How to Answer
This is the classic subset sum problem presented in a way that requires us to construct a list of all the answers. Subset sum is a type of problem in computer science that broadly asks to find all subsets of a set of integers that sum to a target amount.
We can solve this question through recursion. Even if you didn’t recognize the problem, its recursive nature can be guessed at if you recognize that the problem decomposes into identical subproblems when solving it.
Example
“In solving this problem, I would approach it using a recursive strategy, which could efficiently break down the task into smaller, manageable subproblems. I could start by defining the base cases, such as handling when the target sum becomes zero or negative, which would help in controlling the recursion. From there, I would iterate through the list of integers, trying to subtract each from the target and recursively solving for the remaining target. By doing this, I could construct all possible combinations that sum up to the target.”
Here are some tips to help you excel in your Uber interview:
Understand the job description clearly and prepare your resume accordingly. The resume screening determines whether you’ll make it to the interview process, so emphasize your work experience and skills in line with what the recruiter wants to see.
Understand the specific ML applications and technologies Uber uses.
Research Uber’s recent news, updates, values, and business challenges. Understanding Uber’s culture and strategic goals will allow you to present yourself better and determine whether the company is a good fit for you.
Explore the specific role at Uber through our Learning Paths to see how well your skills align with this position.
Visit Uber’s Careers page for tips on preparing for their interview. They also have a valuable guide on their engineering interview process that you should read.
This interview will examine your machine learning and programming knowledge in depth. Know core machine learning algorithms, data structures, and their applications, especially in the context of Uber’s business use cases. Stay abreast of recent trends and news in ML and AI.
Our top tips: Tailor your preparation for each step of the process. Prepare a script for case study and design rounds. Have a strategy to get back on track if your answers get derailed or if you spend too much time on one subtopic. Practice time management, ask clarifying questions, and double-check your solutions beforehand.
To get more hands-on practice, refer to our handy guide on popular machine learning projects. You can also practice Python-based ML questions and check out our top ML interview questions.
Soft skills like collaboration, effective communication, and flexibility are paramount to succeeding in any job, especially in a dynamic work environment like Uber.
To test your current preparedness for the interview process and improve your communication skills, try a mock interview. Participating in multiple mock interviews is particularly useful for design rounds and case interviews.
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You can apply for roles in MAANG companies or similar ride-sharing companies like Lyft. We have interview guides for Google, Apple, Amazon, Meta, Netflix, and Lyft.
For insights on other tech jobs, you can read more on our Company Interview Guides page.
Visit our job portal to check out our current postings. There, you can sort the list by team, location preference, and your current skill sets and apply for your desired role.
Succeeding in an Uber machine learning interview requires a strong foundation in ML algorithms, a winning interview strategy, and extensive prep work.
Understanding Uber’s experimentation-driven culture and thoroughly preparing with both technical and behavioral questions will be key to success. If you need more in-depth preparation, explore our tailored learning path in modeling and machine learning.
For other data-related roles at Uber, consider studying our guides for business analyst, data engineer, software engineer, and data analyst positions in our main Uber interview guide.
Best wishes on your journey to landing a fulfilling role at Uber!