Cracking the Google Code: Your Ultimate Software Engineering Interview Prep Guide | by Pranith_Chowdary | Jan, 2024
This Guide is made with help of my friends who are real Software Engineers and Hiring Manager working at Google. Don’t miss the Resources section at the end…!
Software Engineers (referred to as “SWEs”) at Google develop the next-generation technologies that change how millions of users connect, explore and interact with information and one another. As a SWE, you’ll be responsible for the whole lifecycle of a project critical to Google’s needs, with opportunities to switch teams and projects as you and our fast-paced business grow and evolve. Depending upon the project you join, you could be involved in research, design, planning, architecture, development, test, implementation and release phases. You’ll be working on products that handle information at a massive scale, bringing fresh ideas from all areas and tackling new problems across the full-stack as we continue to push technology forward.
Google is and always will be an engineering company. We hire people with a broad set of technical skills who are ready to tackle some of technology’s greatest challenges and make an impact on millions, if not billions, of users. At Google, engineers not only revolutionize search, they routinely work on massive scalability and storage solutions, large-scale applications and develop entirely new platforms around the world. From AdWords to Chrome, Android to YouTube, Cloud to Maps, Google engineers are changing the world one technological achievement after another.
Explain: We want to understand how you think, so explain your thought process and decision making throughout the interview. Remember we’re not only evaluating your technical ability, but also how you approach problems and try to solve them. Explicitly state and check assumptions with your interviewer to ensure they are reasonable.
Clarify: Many of the questions will be deliberately open-ended to provide insight into what categories and information you value within the technological puzzle. We’re looking to see how you engage with the problem and your primary method for solving it. Be sure to talk through your thought process and feel free to ask specific questions if you need clarification.
Improve: Think about ways to improve the solution you present.It’s worthwhile to think out loud about your initial thoughts to a question. In many cases, your first answer may need some refining and further explanation. If necessary, start with the brute force solution and improve on it — just let the interviewer know that’s what you’re doing and why.
Practice: You won’t have access to an IDE or compiler during the interview so practice writing code on paper or a whiteboard. Be sure to test your code and ensure it’s easily readable without bugs. Don’t stress about small syntactical errors like which substring to use for a given method (e.g. start, end or start, length) — just pick one and let your interviewer know.
Your phone interview will cover data structures and algorithms. Be prepared to write around 20–30 lines of code in your strongest language. Approach all scripting as a coding exercise — this should be clean, rich, robust code.
- You will be asked an open ended question. Ask clarifying questions, devise requirements.
- You will be asked to explain it in an algorithm.
- Convert it to a workable code. (Hint: Don’t worry about getting it perfect because time is limited. Write what comes but then refine it later. Also make sure you consider corner cases and edge cases, production ready.)
- Optimize the code, follow it with test cases and find any bugs.
Coding: You should know at least one programming language really well, preferably C++, Java, Python, Go, or C. You will be expected to know APIs, Object Orientated Design and Programming, how to test your code, as well as come up with corner cases and edge cases for code. Note that we focus on conceptual understanding rather than memorization.
Algorithms: Approach the problem with both bottom-up and top-down algorithms. You will be expected to know the complexity of an algorithm and how you can improve/change it. Algorithms that are used to solve Google problems include sorting (plus searching and binary search), divide-and-conquer, dynamic programming/memoization, greediness, recursion or algorithms linked to a specific data structure. Know Big-O notations (e.g. run time) and be ready to discuss complex algorithms like Dijkstra and A*. We recommend discussing or outlining the algorithm you have in mind before writing code.
Sorting: Be familiar with common sorting functions and on what kind of input data they efficient or not. Think about efficiency means in terms of runtime and space used. For example, in exceptional cases insertion-sort or radix-sort are much better than the generic QuickSort / MergeSort /HeapSort answers.
Data Structures: You should study up on as many data structures as possible. Data structures most frequently used are arrays, linked lists, stacks, queues, hash-sets, hash-maps, hash-tables, dictionary, trees and binary trees, heaps and graphs. You should know the data structure inside out, and what algorithms tend to go along with each data structure.
Mathematics: Some interviewers ask basic discrete math questions. This is more prevalent at Google than at other companies because counting problems, probability problems and other Discrete Math 101 situations surround us. Spend some time before the interview refreshing your memory on (or teaching yourself) the essentials of elementary probability theory and combinatorics. You should be familiar with n-choose-k problems and their ilk.
Graphs: Consider if a problem can be applied with graph algorithms like distance, search, connectivity, cycle-detection, etc. There are three basic ways to represent a graph in memory (objects and pointers, matrix, and adjacency list) — familiarize yourself with each representation and its pros and cons. You should know the basic graph traversal algorithms, breadth-first search and depth-first search. Know their computational complexity, their tradeoffs and how to implement them in real code.
Recursion: Many coding problems involve thinking recursively and potentially coding a recursive solution. Use recursion to find more elegant solutions to problems that can be solved iteratively.
Operating Systems: You should understand processes, threads, concurrency issues, locks, mutexes, semaphores, monitors and how they all work. Understand deadlock, livelock and how to avoid them. Know what resources a process needs and a thread needs. Understand how context switching works, how it’s initiated by the operating system and underlying hardware. Know a little about scheduling. We are rapidly moving towards multi-core, so know the fundamentals of “modern” concurrency constructs.
System Design: System design questions are used to assess a candidate’s ability to combine knowledge, theory, experience and judgement toward solving a real-world engineering problem. Sample topics include features sets, interfaces, class hierarchies, distributed systems, designing a system under certain constraints, simplicity, limitations, robustness and tradeoffs. You should also have an understanding of how the internet actually works and be familiar with the various pieces (routers, domain name servers, load balancers, firewalls, etc.). For information on system design, check out our research on distributed systems and parallel computing.
Books
- Cracking the Coding Interview by by Gayle Laakmann McDowell gives you the interview preparation you need to get the top software developer jobs. This is a deeply technical book and focuses on the software engineering skills to ace your interview. The book is over 700 pages and includes 189 programming interview questions and answers, as well as other advice.
- Programming Interviews Exposed: Secrets to Landing Your Next Job had everything you need to know to succeed in the programming interview and get the job you want Whether you are a veteran programmer seeking a new position or a whiz kid starting your career, interviewing for a programming job requires special preparation.
- Elements of Programming Interviews in Python: The Insiders’ Guide is a python version of book “Elements of Programming Interviews (EPI)”. It is your comprehensive guide to interviewing for software development roles. The core of EPI is a collection of over 250 problems with detailed solutions. The problems are representative of interview questions asked at leading software companies. The problems are illustrated with 200 figures, 300 tested programs, and 150 additional variants. This book is also available in other programming languages like C++ and Java, visit the link to know more.
Stay tuned for more upcomming resources like Technical Guides, Videos, Tutorials, e.t.c.
This guide is more than just a collection of tips and tricks. It’s a structured roadmap to your Google dream job. With dedication and the right preparation, you can crack the code and land your place among the best.
Remember:
- Start early and be consistent: Don’t cram the night before. Dedicate regular time to practicing and refining your skills.
- Focus on fundamentals: Master the basics of data structures and algorithms before diving into advanced topics.
- Practice, practice, practice: Solve as many coding problems as you can, under timed conditions if possible.
- Be yourself, but be your best self: Showcase your personality and unique skills while demonstrating professionalism and confidence.
