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What Middleware Is — & How It Enables Smoother Development

What Middleware Is — & How It Enables Smoother Development

You've probably heard of hardware and software, but did you know that there's middleware, too?

Always working quietly in the background, middleware is often referred to as "software glue" — and for good reason. Without middleware, it'd be much more difficult for applications to run smoothly together. That's why any Full-Stack Developer or Back-End Developer should understand middleware, how it works, how it's used, and the most common types.

What is middleware?

Middleware is a type of software that allows two or more applications to communicate with each other, particularly applications that weren't initially designed to do so.

You might remember that your operating system (OS) is the software that directly controls your device's hardware components, such as the processor, memory, storage, battery, and graphics card. This means that when you install a software application on your computer, that software then communicates with your OS so it can indirectly use your computer's hardware to perform a calculation, playback cat videos, or whatever else it was designed to do.

In other words, whenever an application wants your computer or device to do something, it needs to give your OS instructions on how to do it. That's great if your software is designed to do just one thing. But most software applications are designed to work with other applications, too.

The complexities of ordering lunch

When you open up an application on your phone to order your next meal, your phone isn't just displaying images and text. The application uses the internet to find your location before loading data from its database of nearby restaurants and their menus. Then, you're submitting an online form with your order and processing your payment with a credit card. And if you have a problem with your order, you'll need to send an email or start a phone call. That's a lot of different functions.

Now, imagine that you're in charge of developing this food-ordering app. Your back-end development team might use different industry-standard services for secure payment processing. They may also work with location apps built into your phone to curate options based on location.

They'll also need a database management tool to work with the company's servers to store and retrieve data about restaurants. That's a lot of different applications, and they all need to work together to look like a single app from the user's point of view.

So, what happens when you need different software applications to talk to each other? Remember that your OS is designed for communicating with hardware, not with other applications. That's why we need another type of software, or middleware, that does the job.

Without middleware, developers would need to program ways for each application to communicate individually with each other. It's possible, but it takes a long time, and it's not efficient.

If each application were a house in a neighborhood, life without middleware would be like building a separate road to reach every other house. So, a neighborhood with six houses would have five different roads leading from each. But why do that when you can just build one street and connect each house to the street with a driveway? That's exactly what middleware does.

How middleware works

One central role of middleware is to act as a real-time translator between different applications. That's why a lot of middleware can understand and process several common platform languages like Ruby, C++, Java, and PHP.

But middleware does more than just translate programming languages. It also helps applications communicate with each other by taking the processing power and bandwidth capabilities of different systems into account. This ensures that everything runs smoothly.

Without middleware, there'd be no way to ensure that the output of one application isn't overwhelming the resources of another application using that output. In other words, middleware ensures that connected applications work as a team.

Types of middleware

There are different types of middleware, each with its own function and advantages. Below are the most common types of middleware.

Application programming interface (API)

Application programming interfaces (APIs) are the most well-known type of middleware.

APIs act a bit like messengers. When one application needs data from another, the API delivers the request to the second application and the results back to the first.

Let's say you want to plan a trip and need to find cheap flights. You don't want to look through every airline's site one by one, so you use a third-party travel site instead and enter your travel dates and destinations. The travel website then works with each airline's API to request information about available flights — departure times, prices, seats, and so on — and delivers the results back to the travel website so you can view and compare them to other airlines' results.

What's important here is that APIs provide data only as needed. The third-party website doesn't have direct access to the airlines' databases, which makes APIs more secure and efficient.

Message-oriented middleware (MOM)

Message-oriented middleware (MOM) works similarly to an email system. But instead of helping two people communicate with each other, a MOM lets two applications communicate through asynchronous messages. By "asynchronous," we mean that messages sent to an application server are queued until the application is ready to process the message.

On the back end, MOM is how different applications can communicate with each other through automated messages about system status as well as output and query results. MOM is also used on the front end for people to communicate with applications through web forms and queries.

Object middleware

Object middleware (AKA an object request broker) takes advantage of the principles of object-oriented programming (OOP). The idea of object-based middleware is to pass objects between different applications that share processes, functions, and datasets, even when they’re run on different computers.

Database middleware

When an application needs to communicate with a database quickly, it needs database middleware. Database middleware can work with local or remote databases. A famous example is SQL-based database software, which lets applications quickly search through large databases and return results that other applications can use to perform additional functions.

Transactional middleware

When developers need to rely on many different application servers to execute a single function or modify data, it can be hard to ensure that all steps are completed and in the correct order. Transactional middleware ensures that each separate application does what it's supposed to do when new data is entered, stored, updated, or deleted. It also ensures that updates don’t introduce corrupt data or cause problems for any of the application servers involved.

Middleware and app development

Now that you understand what middleware is, how it works, and its common types, you might already have an idea of why developers love working with it.

Like everyone else, developers don't like having to start from zero if they can help it. Middleware provides a foundation for integrating different applications and software without having to figure out how to get everything connected and working.

Developers already have to work with multiple tools, frameworks, and programming languages. Middleware saves a lot of time and coding by providing a ready-made platform for all of these tools and languages to understand each other.

Middleware tools

We've talked a lot about middleware in general, but what middleware tools are developers actually using? The most popular middleware tools today include:

  • Apache Camel: A MOM middleware used to integrate components and share data between them. It also includes features for adding encryption and authentication functionality.
  • MuleSoft: An open-source tool enabling API connectivity. It also includes Mule Studio, an intuitive development environment, and integrates with tools like Maven and GitHub.
  • SQL Server: A database middleware known for its security and encryption algorithms — and it’s also helpful when you need to recover lost data.
  • IBM CICS: A transactional middleware commonly used in the financial, communications, and hospitality industries.
  • CORBA: A scalable and efficient object middleware used to facilitate communications between an application’s components.

Keep in mind that different companies use different middleware tools depending on their needs and size. For example, Apache Camel is a great tool for small companies working with data that needs to be shared between smaller systems. CICS, on the other hand, is designed for large enterprises and handles billions of transactions per day for banks, airlines, hospitals, and insurance companies.

Middleware can help you as a developer

Understanding middleware can help you along your career path as a developer. Software and tech companies rely on middleware to develop applications more quickly and efficiently. Knowing how middleware works can help you stand out as a promising job candidate.

But development isn't just about middleware. As you build your knowledge as a new developer, we recommend that you never stop learning to make sure that your skills are always sharp and up to date. You can do this with an online programming course to teach yourself a new programming language or build on your existing programming knowledge with new projects. And if you're not sure what to learn next, our career paths will help you focus on the skills you need to succeed in your new career.


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Michael Klein

Michael Klein is a freelancer with a love for statistics, data visualization, and his cat. When he’s not writing for Codecademy, he enjoys geostatistics with R and playing with agent-based models.

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What Middleware Is — & How It Enables Smoother Development
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