How To Prepare for Programming and Coding Interviews? Topics and Skills

There is no doubt that Coding interviews with big tech companies like Google, Microsoft, and Amazon are very difficult, but you can still solve them by carefully planning and preparing the core skills that matter most like data structures and algorithms, system design, multithreading and compatibility, and SQL design And the database, of course Problem solving skills.

Being a Java author and programming blogger, I often receive inquiries about How do you prepare for coding interviews? How do you pass the Google or Microsoft Software Developer interviews? Or how can I get a software development job on Amazon or Facebook?

After answering several of my readers one by one on Facebook and LinkedIn, I thought of making a list of Basic Topics for Coding Interviews.

This list will give you a good start preparing you for any interview with a tech company like Google and Amazon. However, even if you’re not targeting Google and just want a developer job, you can still set up these themes.

In fact, preparing for tech giants like Google, Amazon, Apple, and Facebook means you’re miles ahead of other candidates, and you’ll likely secure many job offers from small businesses, startups, and investment banks.

That’s why I suggest you aim higher because even if you don’t get what you want, you will still get job offers desired by many programmers.

Another important thing to note is that different interviews need different skills. For example, when you go for an interview with a Java developer, you are bound to know Java. Similarly, for a Python developer interview, you are expected to know Python and some popular Python frameworks such as Django and Flask.

For a web developer, HTML, CSS, and JavaScript are essential skills, and you’ll be questioned about them, apart from modern web development frameworks like Angular, React, and Vue.js, with a bit of node.js too.

I won’t go into this topic but I will share the basic skills required to pass all those interviews. Also known as basic programming skills, every software developer is expected to know this.

How to prepare for programming interviews

Anyway, without wasting any more of your time, here is the list of topics you can prepare to boost your chances of programming job interviews at Google, Amazon and Microsoft.

1. System design

This is another important topic that you need to prepare well for programming job interviews, especially at major tech companies like Google, Microsoft, Amazon and Facebook. You need some ideas on how to design your solution from architecture to coding.

The system design is actually quite extensive. At a high level, it covers things like software architecture, I mean the advantage between monolithic and microservice architecture and the choice between NoSQL and SQL database.

Does it cover things like how do we design an app that can handle 10,000 concurrent users? It includes things like scalability.

At a lower level, it covers programming and object-oriented design, which talks about designing your classes and their relationships, following good coding practices, and software design principles such as SOLID.

For this reason, many candidates struggle to answer system design questions, and if you want to succeed, you should focus especially on this skill. If you need a resource, I recommend you check out the System Design Interview Courses, which are prepared by people who have worked as hiring managers at these technology companies and walk you through common system design interview questions.

System design overview

For object-oriented design and analysis, I recommend the Head First-Oriented Objective Design book to learn the basics and practice.

2. Data structure

As a programmer, it’s okay if you can’t write web applications with Django or React, but it’s not good if you don’t know how a hash table works and when to use a list via an array? And, What advantages does B-Tree offer over the Matrix? Data structure and algorithms are the core of computer science and programming, and every software developer is expected to have a solid knowledge of basic data structure.

It is essential to have a good understanding of data structure to write a powerful and efficient application that your users will appreciate.

Imagine, if Facebook or Google took a minute to sign you in, you would never go there, forgetting how important they are. Performance is critical, and unless you understand how your software works and how your data is stored, you’re not going anywhere.

in a Technical Interviews, you will be asked to optimize your solution for time and place. You can only do this if you have a solid understanding of how your code works and how data is stored and accessed.

This is probably the most important topic in coding interviews and you should prepare well. At a minimum, you should know array, linked list, binary trees, binary search tree, self-balancing trees like AVL tree, hash table (or map or dictionaries as they are known in Java and Python), stack, queue, and graph.

You must understand how to store and access the objects from these data structures and the computing cost involved. You should also have a comparative analysis of when to use a particular data structure like a lookup set is faster, and a hash table is better. However, for faster addition and deletion, a linked list will outperform an array.

If you need a resource to keep up with the latest developments, I suggest you choose a data architecture course where examples are presented in the language you feel comfortable with.

3. Algorithms

While it is important to know basic data structures such as array, linked list, and trees, it is also important to know how to work with these data structures. If you don’t know the difference between linear search and binary search algorithms, and what it means to run in O(log n) instead of O(n^2), you need to spend some time learning the algorithms.

Often that’s the difference between a subtle application and a badly slow process that stops more than it runs. At a minimum, you should be familiar with sorting algorithms like quicksort, merge, sort etc. Uber, Grab, and Ola.

You should also understand how the library methods you use to sort an array work, what algorithm you use internally, and when a different algorithm does a better job.

I highly suggest that you prepare for this topic in depth. If you need a resource, I recommend the Grokking Algorithms book for the Aditya Bhargava and Algorithms course on Coursera.

4. Multithreading and concurrency

Concurrency is one of the most sought-after skills by employers, and also one of the most advanced topics brought up in interviews. Because it shows your ability to design software that uses resources efficiently but at the same time is a very difficult subject to master which is why interviewers like it.

Concurrency can also be used to measure your expertise and technical depth and is often used as a key determining factor in the overall hiring level. Whether you’re just entering your career or looking to switch jobs, it doesn’t hurt to take the time to master concurrency.

At a minimum, you should know threads, processes, shared memory, screens, locks, critical partition, and deferred callbacks. Having a good knowledge of how to avoid race conditions and pitfalls can be even better.

Practicing classic concurrency interview questions like Producer-Consumer, Dining Philosopher, and many more can also teach you about concurrency and multithreading and give you the confidence to visualize how code and data work when multiple threads are running in parallel.

If you have an interview coming up, I highly suggest you double up on synchronization. This is because I know it can be one of the most challenging topics brought up during most interviews, even for experienced developers. However, gaining mastery of concurrency gives you a huge advantage over other candidates.

5. SQL and database design

As a software developer, working with a relational database is an important skill that you will need, and it will stay with you no matter where you are in your career.

Every small to large company uses a DBMS, so you are likely to come across different data models, write databases (NoSQL and SQL) and have dependencies on different companies.

Knowing how your data is structured within a DBMS is crucial. Should you use Entity Relationship (ER), Model? hierarchical model? Triangular structure?

The choices can be intimidating, but it’s good to know the different ways to structure your data so that when you switch between database vendors like Oracle to SQL Server or PostgreSQL, you can add minimal manual coding.

As a programmer, you should also know about SQL, not only the syntax but also how the database runs your query, how joins are implemented, how to use indexing, and the difference between table scan, index scan, and index lookup. These details are not only important from a coding interview perspective but also from day to day jobs.

I suggest you go through Basics of Database Design for Software Engineers Courseswhere you’ll learn about different concepts and techniques you can use to structure your data and explore why you use specific approaches to solve specific problems.

You will also be exposed to techniques such as normalization, which help increase database efficiency and avoid duplication. I also suggest using Index Luke’s book to better understand how SQL query works in general.

6. AWS, Docker, and Kubernetes

While these five are definitely necessary skills for coding interviews, nowadays employers are also looking for modern technical skills like AWS, Docker, and Kubernetes, making them important subjects for technical interviews.

Since cloud computing is the next big thing and this decade of software development is going to be cloud native, it is best for a software developer to know about cloud and modern deployment tools like docker And rulers.

This is also important if you want to stay ahead of the curve and give the employer a reason to hire you rather than the next candidate in line. For AWS and Cloud, another thing you can do is get certified, not because you can’t get a job without a degree but to learn better and get recognition for your skills.

Docker is a container that allows you to run your application as a whole, along with all dependencies. This makes both development and deployment easier, especially for microservices. Since a container makes cloud deployment more manageable, it is also easy for a manager to scale and shrink.

Kubernetes is a container orchestration tool, which means that manager containers can be used extensively. It’s easy to deploy and manage a few boxes, but when you have to publish hundreds of containers for your app for a promotional event like Amazon Prime Sale and then need to remove it once traffic is back to normal, it’s not easy. Kubernetes can do this for you, providing automation and peace of mind.

While both Docker and Kubernetes are not mandatory skills for a programmer but they are certainly necessary from a job perspective. I recommend every aspiring software developer or programmer to learn Docker and Kubernetes.

That’s all about some of the most Important skills and topics you can prepare for your coding interview hack For companies like Google, Microsoft, Apple, Facebook and Amazon.

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