1. Data Structures and Algorithms

Many programmers think that data structures and algorithms (DSAs) are just something you have to “get through” in school, but will never need in real life. However, they’re surprised when so many interviews include DSA questions. There are several reasons companies are interested in a prospective employee’s DSA knowledge, and why programmers should be interested in it too.

For many companies, such as Meta, Google, Microsoft, and Amazon, writing code is the final step in a long process. The majority of a programmer’s time is spent considering the best way to approach a project, including the best data structures and optimal algorithms to employ. These decisions impact the company’s resource usage and profitability, so it’s no surprise that DSAs figure prominently in their interview process. And, even for companies outside of Silicon Valley, these questions are important because they demonstrate a programmer’s foundational knowledge and problem-solving abilities.

Once a programmer has the position, DSAs still play a role in day-to-day work. Specifically, data structures are a particular way of organizing data so that it can be used most effectively, and there are many to choose from. One of the most commonly used data structures is an array, which holds and indexes items of the same data type as integers. Additional data structures include linked lists, which organize data into linear, sequentially-linked order; and stacks, which allow programmers to access recently placed items first, as if they were picking up the first book in a pile. 

Algorithms are a set of instructions programmers give to computers to solve a problem, much like the recipe one might give a cook. These step-by-step guidelines can perform a variety of tasks, including searching and sorting data in a way that is ordered and makes sense.

In addition, many startups look for programmers who possess the agility to scale programs and innovate through the use of DSAs.

2. Database and SQL

One of the basic expectations of any programmer is that they are familiar with core database concepts. That is because data is the fuel companies run on, and it proliferates almost every aspect of every project.

While there are many languages used to work with databases, the most common is Structured Query Language (SQL — pronounced “sequel”). Though SQL was developed in the 1980s, it is still the standard language used to communicate with relational databases and is considered critical for modern programmers. In recent years, SQL has been heavily used by PC databases because it facilitates access to distributed databases (e.g., those spread out over multiple computer systems); allowing several local users to access the same network simultaneously. SQL also enables easy storage and organization of data in relational databases (e.g., databases where tables are related to one another through common data).

If you’re interested in gaining SQL experience, it may be helpful to practice with MySQL. Referred to as a relational database management system (RDMS), this open-source software is based on SQL and many aspiring coders use it to work on developing their systems, applications, and websites for free.

NoSQL, on the other hand, is a database management system (DBMS) that stores and accesses data using key values, rather than relationally, which offers some additional flexibility. One example of a NoSQL database is MongoDB, an open-source program that can be used for high-volume document data storage and deals with document structure variations nicely.

Of course, there are many more systems and software packages to learn when mastering databases, but having a strong foundation in database concepts and SQL is an important first step for all programmers.

3. Object-oriented programming (OOP) languages

OOP languages support a way of programming (sometimes called a paradigm) that relies on classes and objects. Think of classes as groups of similar things, such as fruits, with objects that tell us more about individual items in that class, such as apples. This programming paradigm is important because it allows programmers to easily reuse complex code across programs. For example, if I say “my apple,” it isn’t necessary for me to tell you all the attributes of my apple (i.e., red, round, grew on a tree, belongs to me). Similarly, by using an object from a class (fruit), a programmer can easily communicate instructions or information across multiple programs, enabling more effective and efficient coding as a result.

For this reason, OOP languages such as Java, C++, Python, and Perl are meaningful for programmers, and they need to have at least one in their skill set.

In addition, such languages as JavaScript and PHP pair well with OOP languages to further enhance efficiencies and functionality.

4. Integrated Development Environments (IDEs)

Combining a variety of developer tools through a single graphical user interface (GUI), IDEs are a workbench for programmers where all the tools they need are laid out and ready for them to use — kind of like a workbench with a saw, drill, nails, and a hammer if you were planning to build a birdhouse.

IDEs are valuable in that by learning one IDE, a developer can become familiar with a variety of tools that work synergistically, rather than learning each tool separately and pulling together the right tools for each coding task. In addition, because all the tools are available through one GUI, the programmer doesn’t have to spend time switching between applications.

• AWS Cloud9: Supports over 40 languages, including JavaScript, Python, PHP, Ruby, Go, and C++ 
• Code: Blocks: Supports C and C++
• Eclipse: Supports Java
• Eclipse Theia: Supports over 60 languages, including JavaScript, Java, and Python
• GNAT Studio: Supports Ada, SPARK, C, C++, and Python
• IntelliJ IDEA: Supports Java, but understands many other programming languages, including Groovy, Kotlin, Scala, JavaScript, TypeScript, and SQL
• NetBeans: Supports several languages including, Java, PHP, JavaFX, and JavaScript
• PyCharm: Supports major Python frameworks such as Flask, Django, web2py, Pyramid, and Google App Engine 
• SlickEdit: Supports over 70 languages, including C++, Java, HTML, PHP, JavaScript, Python, Perl, and Ruby
• Xcode: supports Swift, but allows coding in C, C++, Objective-C, Objective-C++, Java, Applescript, Python, React.js, and Ruby
• Visual Studio: Supports C, C++, C++/CLI, Visual Basic .NET, C#, F#, JavaScript, TypeScript, XML, XSLT, HTML, and CSS
• Visual Studio Code: Supports many languages including, C++, C#, CSS, Dart, Dockerfile, F#, Go, HTML, Java, JavaScript, JSON, Julia, PHP, Python, SCSS, T-SQL, and TypeScript.

It’s also important to remember that while cloud-based IDEs aren’t constrained by the programmer’s operating system, this is a useful constraint for IDEs that aren’t cloud-native.

5. Cloud computing

Cloud computing is experiencing explosive growth, as cloud developers are needed for all businesses that wish to migrate their environments, storage, and digital assets to the cloud. In fact, according to LogicMonitor, 87% of global IT decision-makers agree that the COVID-19 pandemic has accelerated cloud migration for most organizations. In addition, once migrated, businesses will need programmers familiar with the technology necessary to work effectively with cloud-native applications. And, as businesses rely more heavily on data science, machine learning, and artificial intelligence, work in the cloud becomes even more important since algorithms and models consume significant resources. The result of these business transitions and needs is that cloud engineers and developers, as well as cloud-savvy programmers, are in high demand.

In addition, it’s a good idea for programmers to familiarize themselves with cloud platforms, such as: 

• Amazon Web Services (AWS)
• Microsoft Azure
• Google Cloud Platform (GCP)

Even focusing on just one, to learn key functionality, will help you gain a better understanding of how the others work, adding value to your skill set.

6. Web development

Many professionals consider web development a subset, or specialization of programming. Therefore, it only makes sense for those who plan on working in web development to learn the associated languages and tech, right? Well, maybe not.

Certainly, programmers who plan to work in web development need to have a strong background in the core tools. Some of these tools include:

• HTML/CSS: HyperText Markup Language (HTML) and Cascading Style Sheets (CSS) are both basic coding languages — often, they are the first two that web developers learn. HTML helps organize the content and structure of a web page, while CSS determines its style and presentation.
• JavaScript: JavaScript is most commonly used for frontend development, though it is sometimes used for backend development as well. As one writer for Mozilla explains, “Every time a web page does more than just sit there and display static information for you to look at — displaying timely content updates, interactive maps, animated 2D/3D graphics, scrolling video jukeboxes, etc. — you can bet that JavaScript is probably involved.”
• API: An API (Application Programming Interface) is the part of a remote server that receives a user’s requests and sends responses to the rest of the server and website. Programmers set up a website’s API to complete user requests and connect them to an external server without leaving the original site. Having familiarity with APIs ranks high on any web development skills list because it helps improve a customer’s experience on websites.
• PHP: PHP (Hypertext Preprocessor) is a highly accessible, general-purpose scripting language that can be easily embedded into HTML to accentuate frontend programming efforts. Unlike JavaScript, PHP is executed entirely on the server-side, rather than the client side.

With that said, even programmers who don’t plan on working in web development can benefit from understanding the basics. For example, many projects that programmers work on include a web component. With some foundational knowledge of web development concepts, concerns, and constraints, programmers are better able to understand how data will be collected and used, what functionality may be required at a later date, and how enterprise systems may be impacted in the future. Certainly, this knowledge will help programmers have a more comprehensive understanding of not only the best way to develop their portion of the project but also how to offer additional solutions to those whose expertise is focused on client-side functionality.

7. Containers

Containers are preconfigured environments that package code and other dependencies an application needs to run, without the need for downloads to a physical computer. Unlike traditional methods where code is developed in a specific computing environment and transferred to a new location resulting in bugs (i.e., virtual machines), containers bundle the application code with related configuration files, libraries, and dependencies which minimizes the potential for bugs. In addition, because the operating system (OS) files are included, containers virtualize the operating system and the application can run anywhere. As a result, programmers can develop and deploy applications in a faster and more secure manner. 

A basic example of container usage in education is a teacher preparing for their Python programming class. By using a container, they can grab the necessary application, libraries, and dependencies (including the OS), making it easier to prepare while ensuring learners will have the necessary access to learn Python from anywhere. 

Some of the most popular container management software include:

• Docker
• AWS Fargate
• Google Kubernetes Engine
• Amazon ECS
• Linux Containers
• Microsoft Azure Container Services

8. Text editors

Text editors are programs that enable the opening, viewing, and editing of plain text files. Because text editors do not add formatting to text, as word processing programs do, programmers can use text editors to easily write and edit in programming and markup languages. In addition, text editors help programmers create documentation files and maintain configuration files.

9. Git

Git is a version control system that allows programmers to manage and track changes to source code throughout the development process. It makes it easy to correct any errors that may occur because every version is saved and can be recalled on demand. And, using version control encourages programmers to innovate through trial and error, as they don’t have to worry about losing previous coding attempts.

Git is the most widely used version control system among employers, so it’s important to be well-versed and ready to use it when approaching a career in programming.