Top Software Developer Interview Questions at General Motors (GM)

General Motors (GM) is one of the world’s largest automotive manufacturers and a leading global company. GM frequently hires software developers to work on innovative technologies for their vehicles. Software developers at GM get the chance to program vehicle components, infotainment systems, self-driving car systems, and more

Landing a software developer job at a prestigious company like GM requires thorough preparation for the interview. In this article, we will look at some of the most common GM software developer interview questions and how to best approach them.

Overview of GM

General Motors is based in Detroit, Michigan, and makes cars under a number of different brands, such as Chevrolet, GMC, Cadillac, and Buick. They have over 180,000 employees globally. GM spends a lot of money researching and developing the cars of the future, such as electric and self-driving cars.

Software developers are a key part of bringing GM’s innovations to life. Developers work on embedded systems programming vehicle infotainment like navigation systems EV and AV software stacks, machine learning, cloud computing, and more. GM provides software developers opportunities to gain experience across multiple domains.

Now let’s look at some sample GM software developer interview questions and answers:

Technical Questions

Q1: How would you design the infotainment system for a connected autonomous vehicle?

When designing the infotainment system for a self-driving car, I would focus on enhancing the passenger experience. Since the vehicle handles navigation and driving functions, the infotainment system can provide entertainment, internet connectivity, comfort controls, and more.

I would allow passengers to connect their smartphones to access playlists, video streaming apps, audiobooks, etc. I would integrate voice controls to easily access content. I would also include options to control climate, lighting, massage settings to maximize comfort. The system should be responsive and customizable per user preferences. Security would be a key consideration to prevent unauthorized access.

Q2: How does collision detection and avoidance work for self-driving cars?

Self-driving cars use a combination of sensors like radar, lidar, and cameras alongside software for collision detection and avoidance. The sensors continuously scan the surroundings in all directions to build a real-time 3D map.

The software processes this sensory data to identify potential collisions – both with static objects like trees and pedestrians and moving objects like other vehicles. Based on the collision risk analysis, the vehicle planning algorithms plot a safe new trajectory to avoid the collision. This could involve braking, steering maneuvers, or speed adjustments. The vehicle controls then follow this new trajectory while remaining stable. The entire sensing and reaction process happens continuously to navigate safely.

Q3: How would you improve software performance for an in-vehicle infotainment system?

I would start by profiling the software to identify any slow or resource intensive areas in the code. I would check for loops and sequences that can be optimized, minimizing dependencies, caching repetitive calls etc.

For GUI optimization, I would remove unnecessary UI refreshes, optimize graphics rendering, and ensure efficient event handling. Compressing assets like images and videos also helps.

If hardware bottlenecks like RAM usage are a factor, I would optimize memory allocation in the code.

Multithreading and parallelizing independent tasks can also boost responsiveness. Hardware upgrades to add CPU cores or RAM may be warranted if optimizations are insufficient.

Coding Questions

Q4: Write a function to reverse a string recursively without using loops.

def reverseString(str):  if len(str) == 1:    return str    return reverseString(str[1:]) + str[0]print(reverseString("Hello")) # Prints olleH

This recursive function slices the string starting from the second character, calls itself on the sliced portion to keep reversing it, and keeps appending characters from the start to build the reversed string.

Q5: How can you optimize a search algorithm on a sorted array?

For sorted arrays, binary search outperforms linear search. The key steps are:

1. Determine starting point, end point and midpoint
2. Compare value at midpoint to target
3. If match, return index
4. If target is greater, search right half
5. Else search left half
6. Repeat until found or array portion is empty

The divide and conquer approach of binary search improves time complexity from O(n) to O(log n).

System Design Questions

Q6: How would you design real-time traffic monitoring for autonomous vehicles?

I would leverage crowdsourced traffic data from fleets of AVs in a region to build a real-time traffic monitoring system. Each AV can anonymously report its speed, GPS coordinates, sudden braking events, and road conditions.

This data can be collated on the cloud and aggregated to identify congestion hotspots, accidents, and other alerts. Traffic flow can be visualized on a dashboard showing a color-coded map of the road network based on congestion levels for different segments.

The cloud system can push updates to routing algorithms running locally on each AV so they can proactively reroute to avoid congested zones. This allows AVs to anticipate and adapt to live traffic patterns.

Q7: How would you update software across a large fleet of autonomous vehicles?

I would design an over-the-air (OTA) update system to deploy software updates remotely. All vehicles would have a module to receive and install updates from the cloud.

Updates can be targeted based on vehicle model, region etc. I would implement robust verification including version checking and testing on a small batch before wide roll-out.

To avoid vehicles going out of service during updates, I would design updates to happen in phases – installing prerequisites, running pre-update checks, switching to redundant systems, fail-safe recovery etc.

I would provide controls to schedule, monitor and if needed, rollback updates. Diagnostics would help identify any vehicles with update failures. Overall this approach allows efficiently keeping large fleets up-to-date.

General Interview Questions

Q8: Why do you want to work at GM?

GM is at the forefront of transforming the future of transportation with innovations in electric and autonomous vehicles. I am deeply passionate about being part of developing cutting-edge software solutions that redefine mobility. GM’s extensive resources, expert talent and pioneering vision make it the ideal place to grow my skills and make meaningful contributions.

Q9: How do you stay up-to-date on the latest technologies?

I regularly read technology publications and blogs focused on the automotive, embedded systems and autonomy domains. I follow thought leaders and innovators in these spaces on social media. I attend tech conferences and workshops related to my focus areas. Within work, I like participating in hackathons, building proofs of concept and taking on challenges just beyond my expertise – this accelerates learning. Overall, I believe it’s important to continually expand your knowledge across the technology landscape.

Q10: How do you prioritize tasks when working on multiple projects?

I first consult with managers and stakeholders to understand business priorities, milestones and resourcing needs across projects. I create a priority matrix mapping out projects based on importance and urgency.

I assign effort estimates for activities and focus on high priority critical path items first. I reevaluate priorities frequently and adjust schedules if needed. Clear communication and coordination with my team is key so we balance efforts across projects smoothly.

GM’s software developer interview will assess your technical expertise, problem-solving abilities and passion for the automotive domain. Solid preparation using these example questions will help you demonstrate your capabilities and land the GM developer job. The key is to show an eagerness to take on complex challenges and deliver innovative solutions. With the right mindset and responses, you can begin an exciting career developing revolutionary software at one of the most iconic companies driving the future of transportation.