The ultimate guide to SaaS integration

Organizations across sizes have invested aggressively in SaaS (Software as a Service) applications over the past several years.

According to research by Vendr, companies with less than 100 employees have increased their spend on SaaS applications by nearly 400% from 2020 through 2022; and companies with 200-499 employees have more than doubled their level of SaaS spend over the same time period. The average organization now uses 130+ SaaS apps!!

As organizations look to reap the full benefits of their ever-growing SaaS investments, they’ll likely need to integrate the applications and build data flows that work across them. Similarly, they’ll need and expect their SaaS providers to offer up a comprehensive set of integrations.

To help you better understand and make full use of SaaS integrations, we’ll break down:

  • What is a SaaS integration
  • Examples of SaaS integrations
  • The importance of SaaS integrations
  • How to integrate SaaS applications -- both for internal and customer-facing use cases

SaaS integration definition

It’s the process of connecting SaaS applications via their APIs. SaaS integration encompasses both internal and customer-facing scenarios. In the former, an organization connects the applications they use internally; in the latter, an organization offers integrations between their SaaS product and the SaaS apps their clients use.

Types of SaaS integration

Note: SaaS integration is often used interchangeably with API integration and application integration, but these terms don’t fully overlap. For example, SaaS integrations can rely on connectivity methods that extend beyond APIs, such as UI-based integrations; while application integrations can include on-prem systems.

Related: What is point-to-point integration?

Examples of SaaS integration

To help make this definition more tangible, let’s cover some common use cases of SaaS integration:

Sync leads between your marketing automation platform and CRM

As your marketing team engages in activities to capture and nurture leads, your reps will need to be kept fully in the loop so that they can step in at the right time and engage the warm leads thoughtfully. 

To help enable reps to do just that, you can connect your marketing automation platform (e.g. HubSpot) with your CRM (e.g. Salesforce) and build a data flow where any time a lead is created or updated in the former, the corresponding changes get reflected in the latter.

Add employees from your clients’ HRIS solutions to your gift-giving software 

Imagine you offer a gift-giving software that allows HR teams to give employees gifts at key milestone events, like birthdays, work anniversaries, or promotions.

To help facilitate gift-giving as soon as one of these moments occurs, you need accurate, comprehensive data on employees from the moment they join. Moreover, you need to be able to update employee data in your application when any relevant changes take place in your clients’ human resource information system (HRIS) solutions.

With this in mind, you can offer product integrations between your application and your clients’ HRIS platforms. Once a connection is successfully established, you can build a sync where any time an employee gets added to the HRIS or specific fields associated with their profile get edited, the corresponding changes get reflected in your application in, or near, real-time. 

Create and maintain customer documents in your file storage platform 

Working with clients naturally involves creating and signing important documents, whether that’s a statement of work, an invoice, a non-disclosure agreement, etc. 

Simply storing these documents in the client’s account within your ERP system can easily lead them to go missing or to be inaccessible to certain stakeholders.

To help prevent either situation, you can integrate your ERP system (e.g. NetSuite) with your file storage platform (e.g. Box) and build the following workflow: Any time a new document gets added for a client in the ERP system, a folder gets created for that client (assuming it doesn’t already exist) in the document storage solution and the document gets uploaded to that folder. You can also build a bidirectional sync between the clients’ ERP account and their folder to ensure that any net-new documents or changes to existing ones get reflected in both applications.

Related: The top challenges of implementing SaaS integrations

SaaS integration benefits

Integrating SaaS applications can prevent human errors, enhance the employee experience, minimize SaaS spend, and more. 

Let’s take a closer at the benefits of SaaS integration:

Reduces human errors

Performing tasks manually, such as copying and pasting data between applications, can often lead to costly mistakes. For example, in the process of copying and pasting details on a closed opportunity from your CRM to your ERP system, you might accidentally input an incorrect dollar value for the closed opportunity in the latter—leading you to invoice the client by the wrong amount. 

Human errors, like the one highlighted above, can be eliminated through SaaS integrations, as employees can avoid the error-prone task of copying and pasting information between applications.

Elevates the employee experience

Data entry doesn’t just compromise data integrity—it can also be unpleasant for employees to perform. Case in point: Employees cite data entry as one of tasks they hate to perform most.

SaaS integrations can help minimize the amount of data entry employees perform. As a result, they can focus on the strategic work that's more impactful to the business and that they’re more likely to enjoy.

Minimizes SaaS spend

By allowing data to flow to more applications, a greater proportion of your employees can access the data they need to carry out their work. This, in turn, prevents them from investing in additional tools to access that same data. 

Improves customer retention and expansion

Since product integrations allow your product to provide more value and unlock additional use cases, they can elevate your customer retention rate and even help you upsell to clients.

Enables you to move upmarket

As you look to move upmarket, you’ll likely find that prospects use a different set of applications in a given software category. For instance, in the case of an HRIS, a smaller company is more likely to use an application like Gusto, while a larger company is more likely to use Workday.

If you can provide the customer-facing integrations that prospects upmarket use across relevant software categories, you’ll be more likely to win over their business.

Related: The benefits of integrating SaaS applications

SaaS integration challenges

While SaaS integrations are, clearly, invaluable, implementing them isn’t always easy. Here are some of the top challenges to be aware of.

Note: These challenges largely apply to companies that are building and maintaining their integrations in-house.

Inadequate API documentation

As your engineers look to build to a 3rd-party API, they might find that the API provider’s documentation is incomplete, difficult to navigate, and/or poorly written. In some cases, they may not even be able to access the documentation (i.e. its availability can depend on your partnership with the API provider). 

A screenshot ofGitHub's API documentation
GitHub, a developer platform for creating, storing, managing, and sharing code, offers extremely comprehensive and digestible API documentation. Unfortunately, the quality of their documentation is the exception, not the norm.

All of this leads your engineers to take longer to build to the 3rd-party API—assuming they’re able to build the integration at all. It can also cause them frustration and stress, which can make them more disengaged and unhappy in their role. 

Difficult to diagnose and troubleshoot broken integrations 

SaaS integrations will inevitably break.

Unfortunately, the process of uncovering the root cause of a given issue, identifying the necessary steps to remediate it, and performing those steps can prove complex and time consuming—leading the issue to persist and affect your employees and clients in meaningful ways. Moreover, forcing your engineers to move away from their current work every time there’s an issue can lower their productivity and job satisfaction.

Never-ending demand for integrations

Organizations are adopting a growing number of SaaS applications. Assuming this trend holds, the demand for SaaS integration will increase indefinitely. 

In other words, your business will need to allocate a growing number of resources toward building and maintaining SaaS integrations over time. 

This can stretch your team thin (if they aren’t already), and it can lead to difficult trade-off decisions. For example, your developers might decide not to build several in-demand integrations in order to focus on your core product; or, conversely, they may decide to build integrations at the expense of building out and improving your core product.

Related: A look at the top integration challenges

SaaS integration best practices

Here are just a few to keep in mind:

  • Prioritize integration builds based on their projected business impact. Integrations aren’t created equal; some may have a greater impact on time savings, customer retention, acquisition, market expansion, etc. than others. Understanding each integration’s potential impact and weighing it against the resources needed to build and maintain it can help you pinpoint the integrations that should be built before others. 
  • Avoid relying on one or two developers for a given integration. The last thing you want is for the one or two developers who are familiar with an integration to leave your company, as this can leave your business poorly positioned to maintain and improve the integration. To prevent this scenario, you can allocate additional engineers to a given integration project and/or task the engineers who work on an integration with writing up and maintaining documentation on it. 
  • Adopt a future-proof, 3rd-party integration solution. Your integration needs will likely grow and evolve in unpredictable ways. Assuming you decide to outsource your integrations, you should pick a solution that can accommodate this uncertainty over time. Put simply, you need a 3rd-party integration solution that’s flexible, scalable, and easy to use. 
  • Iterate and improve your integrations over time. Your integrations may not initially work as expected. In addition, depending on how your applications (or your clients’), processes, and goals change over time, there may be better ways to implement a given integration. To accommodate both scenarios, you should constantly revisit your integrations (e.g. every 6 months) to determine if and how they can improve.

How to integrate SaaS applications

Once you’ve ready to invest in SaaS integration, you’ll need to decide on your approach. We’ll review the top options to consider when implementing integrations internally and when building them between your product and your client’s 3rd-party SaaS applications. 

Integration options for internal use cases

Here are the 3 options you’ll likely consider for internal integrations:

Native integrations

A native integration is simply when your engineers build and maintain the integrations.

A visual representation of native integrations

Native integrations allow you to avoid working with a 3rd-party. Also, if you only have a few integrations to build and the integration functionality you need is relatively limited, they can potentially meet your integration requirements. 

That said, they’re extremely time consuming for your engineers to build and maintain. In many cases, integration projects would force your engineers to focus less on core product initiatives, which can have long-term consequences on your product.

Related: Native vs 3rd-party integrations, A guide to maintaining your product integrations


An integration platform as a service (iPaaS) lets you integrate SaaS applications either via their pre-built application connectors or through the custom connectors you'd build in their SDKs.

A visual illustration of iPaaS

They can help accelerate integration development and provide time savings for your developers. In addition, since they allow you to monitor integrations through a centralized location, your team can more easily manage each over time. 

That said, they still require users to have a certain level of technical expertise. In addition, users may have limited visibility on an integration's performance (i.e. the iPaaS provider often doesn’t reveal why specific issues occur, which puts the onus on users to diagnose and resolve the issues). 


Robotic process automation (RPA) software uses scripts, or “bots”, to mimic human tasks at the UI level.

The software is ideal when the applications don’t offer APIs for the specific data you need to collect and sync. 

That said, the bots can require technical expertise to set up and maintain, and they’re relatively brittle. For instance, a simple change in an application’s UI can be enough to break a bot.

Integration options for customer-facing use cases

Here are some of your options for integrating your product with 3rd-party applications (in addition to native integrations):

Embedded iPaaS

An embedded iPaaS is exactly how it sounds: It’s a solution that lets you embed its iPaaS offering directly into your product. 

You have a few options for deploying it. Namely, you can build all of the integrations yourself and have them be fully functional in your product by default; or you can allow clients to implement the integrations they want within your application (you can also adopt a combination of both approaches).

It offers similar benefits and drawbacks to an iPaaS. 

It can accelerate integration development and assist with maintenance to some extent. But since the platform requires technical expertise to use, forces you to build one integration at a time, and offers limited performance insights, it’s ultimately difficult to build and maintain integrations at scale with the platform.

Unified API

A unified API, also known as a universal API, is a single, aggregated API that allows you to offer multiple integrations in a given software category (e.g. file storage).

A visual illustration of a unified API solution

Since you only have to build to the unified API to unlock several integrations, this type of platform is naturally more scalable than the alternative options. That said, not all unified API platforms are the same.

Merge, the leading Unified API solution, stands out for several reasons. 

The platform offers several unified API categories and hundreds of integrations, all but ensuring you can build the integrations your clients need; it provides comprehensive Integrations Management capabilities, including the ability to diagnose issues automatically and provide steps for remediating them; it uses comprehensive common models across its unified APIs—along with features to access fields and objects that extend beyond them—, and much, much more.

Learn how Merge can help you scale your product integrations by scheduling a demo with one of our integration experts.