BLOGAnnounced at MongoDB.local NYC 2024: A recap of all announcements and updates — Learn more >

Middleware Explained

Middleware is just as it sounds: It’s the middle-man software that allows for different technologies that weren’t designed to connect, to collaborate and work together properly. It’s the key step in ensuring the requests made by the front end are connected to the data kept in the back end.

Middleware is the bridge that allows for information to be transported accurately between various applications, and it helps these separate applications run efficiently together. It’s very commonly referred to as “software glue”.

There are many uses for middleware, middleware in cloud computing being one of the most common, as it’s software that enables computers and other technological devices to collaborate with various applications. So, how exactly is this done, and what are the middleware technologies that enable this process to work? These are questions that we will answer below.

How middleware works

Middleware is crucial for developers because it allows them to build complex applications without having to also build custom mergers when it’s necessary to connect the various technologies used inside the application. This is done through common frameworks and communication services: providing messaging by using XML (extensible markup language), REST API (representational state transfer), SOAP (simple object access protocol), JSON (JavaScript Object Notation), etc. and this allows for different languages (Python, C++, Java, SQL, etc) to talk to one another.

Middleware connects applications that weren’t designed to be connected in intelligent ways, so the incorporation of these technologies allows for developers to streamline their applications and help bring them to market faster. This allows developers to be more creative, time efficient, and it ensures they do not have to “reinvent the wheel” every time they want to connect multiple applications. Middleware also provides services that help developers from the inside out: It controls connections and integrations, allows for secure connections and data transfer, manages traffic, etc. These services allow developers to create complex applications easier.

Middleware is the bridge between applications, data, and users.

What are the basic types of middleware?

There are various types of middleware and middleware services that developers can use to customize their applications perfectly for deployment. The basic types of middleware are: message-oriented middleware, application programming server middleware, database middleware, and transaction middleware. The list below describes these various middleware examples.


Message-oriented middleware, or MOM, is an asynchronous communication framework. Data is exchanged by this system via the messages sent and received. This type of middleware allows for various applications to talk to each other.


Remote procedure call, or RPC, is a way for programs to communicate across networks, without having to truly understand the other network's specificities. It can also be used to communicate between different applications on the same network.


Application programming interfaces, or APIs, are a way to access middleware services. They are tools and protocols that make it possible for various applications to accurately talk to one another. Completely different applications are able to communicate through the use of APIs, as they are connected through a common layer.

Database middleware

Database middleware allows for direct database access, meaning it’s possible to directly interact with your database from your application. Mongoose is an example of database middleware that includes query, aggregate, model, and document middleware.

Transaction middleware

Transaction middleware is essential for executing electronic transactions. It’s the way any execution in an application, or when a user interacts with a computer, is processed. It has been around for over 30 years.

What is middleware in cloud computing?

Cloud computing refers to accessing various applications online instead of locally from your machine. These applications consist of a multitude of tools, data storage options, servers, etc. Middleware in cloud computing is extremely important for developers to access different resources and applications across different frameworks without having to worry about the complexity of each individual framework.

An example of middleware in cloud computing is when you have a common API that supplies data to a variety of platforms — mobile devices, personal computers, video game consoles, etc. — and the data needs to be flawlessly integrated into each of these applications. Middleware is beneficial here because it enables ease of use instead of reconfiguring each individual connection. It’s crucial for businesses as it allows diverse technologies to be easily integrated. This allows for developers to work faster and more efficiently, and have their entire process be streamlined.

The advantages of middleware

Some of the advantages of middleware include:

  • Interface uniformity

    Middleware allows for streamlined application development where the application architecture is simplified and easier for clients to use. This also means that a user can talk to the server in one language, regardless of the language used in the back end.

  • Saves time

    Middleware saves developers time with creating applications since they don’t have to create their own complex application integrations every time. Applications become modular.

  • Makes it easy to connect complex applications

    Middleware makes it easy to integrate whichever complex technologies are needed for a full stack application. Multiple components, languages, and platforms can be used.

  • Portability

    Middleware has made it so software can easily be transferred from a host machine to any other machine or system.

  • Parallel programming

    Parallel programming is the system of taking a large problem and breaking it down into smaller tasks that can be worked on simultaneously. Middleware infrastructure is capable of doing this well.

Middleware and MongoDB

As mentioned above, Mongoose is a JavaScript object-oriented programming library. It’s a program that establishes a connection between your MongoDB database and Node.js environment. Mongoose has various middleware functions that can help developers better access and utilize their MongoDB databases in their applications.

MongoDB App Services are another example of middleware and MongoDB. App Services is available through MongoDB Atlas and offers customers fully managed cloud services, some of which are functions, triggers, and APIs. These applications, along with Atlas, allow users to create deployment-ready products without having to spend time creating the infrastructure that would be needed without the already produced middleware.


What are the three types of middleware?

Middleware functions can be separated into three main sections: application, information-exchange, and management/support middleware. There are many various sub-groups of middleware to be aware of.

Are middleware and API the same?

No, middleware and API are not the same, but APIs (or application programming interfaces) are a way to access middleware services.

Is middleware an interface?

Middleware is technically not an interface, but it can incorporate interfaces (such as APIs) to manage the connections between various applications.

Is Java a middleware?

There are a multitude of middleware technologies that are built using Java, but Java itself is a programming language.

Is middleware software or hardware?

Middleware is a type of software.

Is middleware a back end?

No, middleware is not a back end. Middleware is software that is in-between the front end and the back end and that allows them to communicate flawlessly.

Is PHP a middleware?

PHP is an open source scripting language. There are many middleware applications written in PHP, but it’s not technically a middleware itself.