Five Common API Integration Issues and How to Avoid Them

How can enterprises improve API integration? Find out common issues and how to avoid them.

March 15, 2023

Software integration has come a long way over the years. Gone are the days of finding libraries to link with your code only to have a version change cause clients to crash around the world. With the more recent adoption of higher-level application languages, low/no-code solutions and the pervasiveness of JavaScript and JSON, it’s never been easier to integrate with third parties. Kevin Marcus, CTO of Versium, looks closely at the most common issues faced in API integration and strategies to work around them.

According to Google Trends, interest in the older integration term “SDK” (software development kit) has fallen from 60 to 20, while “API integration” has gone from 20 to 80 in the last 15 years. This titanic shift highlights both the need for patching together best-of-breed functionality while reducing the overall cost of software development. 

As economic conditions force companies to look for ways to do more with less, we may have finally arrived in the golden age of API-based software development: leveraging APIs can help avoid costly development, infrastructure, maintenance and support costs while yielding best-of-breed functionality. Therefore, it’s essential to understand some key integration issues that can arise and how to work through them.

See More: Why APIs and Microservices Are Vital for Digital Transformation

1. Interface Details are Important

The “Interface” portion of API development work is probably the most important component to understand. You’ll need to study not only the types of things you will pass in or receive back, but also their structure. Strong documentation or a test sandbox can help expose any potential issues before engineering begins coding.

For example, consider integrating with a payment gateway for credit card transactions. If their API accepts a currency type, examine how the interface accepts it. It could be via the actual payment amount and character (amount: “$1.23”, or amount: “€1.23”) or separately indicated (“currency: USD,” “currency: Euro”), or some other variation. If this is done the same way your system already tracks transactions, it will be easier to integrate.  

Simpler interfaces that closely match your own data structures should be favored.

2. API Key Management

Most APIs include some form of authentication paradigm. One common example is to have an authentication token within an HTTP header or even as part of a URL request. While most APIs make this pretty simple, you’ll still need to consider how these keys will be managed. An important consideration here is how often the keys change. Some APIs will have keys that change per package or per purchase; others have a single key that grants access to one or many services. If the keys have expiration dates associated with them, you’ll need to be sure to track this or have a monitor to indicate when you’re nearing expiration time.  

When the keys themselves change, these are usually pretty simple to adjust, but if multiple departments are calling the same service with the same key, it might become difficult to track where the key appears or which department has access to change it. A centralized API key management solution may be in order where all clients from all departments use the same interface and key. Of course, the converse is also true: separate departments need to have separate billing line items for API usage, but you need the coded interface to be the same. Here, you’d want to be able to have the keys managed independently by department. 

3. Scalability

While many API-based services are themselves hosted on highly scalable cloud platforms, the implementations of their service can still introduce scalability issues that warrant attention. Rate limiting by an API provider is a common way to avoid overloading their service, but this can also significantly impact your ability to burst during traffic spikes. For example, if you have a web-based lead generation form, one might perform address standardization or various identity validation checks on the information submitted. However, if there are rate limits to the number of checks that can be performed per second, this API may begin to limit responsiveness during a traffic spike. It could manifest as slowed responses or simply return back with errors and not perform the standardization.  

Even though the cloud offers virtually infinite scale for these providers, another serious scale issue can occur when the processing chore has non-computing oriented challenges.  There are many email validation services available with sleek APIs. However, the process of trying to determine email deliverability itself is dependent on many factors outside of typical scale-limiting factors such as CPU, memory and disk. APIs that use the network themselves are prone to upstream scalability issues, especially around latency. In this case, some mail hosts may have delays before connecting or responding, meaning each query could take tens of seconds to complete. If this service is directly embedded in a user’s path through a website, this could slow a user’s purchase.  Furthermore, some APIs impose rate limits and may cause issues with bursts or multithreaded systems. 

4. Stale / Switching / Removal

Just as with normal software, APIs change regularly. Most API developers appreciate backward compatibility and generally don’t change interfaces. More commonly, the business case changes – a better, faster, cheaper competitive solution comes along – and now it’s time to switch!

Sometimes simple changes can wreak havoc on a well-manicured data workflow: new elements may be needed, or required elements may suddenly be missing. Here, understanding how data travels through your application will be key to a smooth integration.  Successful transitions require the study of Interface compatibility, data migration and the creation of a solid testing plan. Sometimes tests from the old API may no longer be valid, and the new API may require a new set of tests, so working backward from test cases can help guide a successful switch.

See More: Modern Calendar APIs: Doing More Than Ever

5. Testing and Logging

While most developers will focus on functionality, error handling and performance, there are several real-time considerations that are often overlooked.  Many APIs offer a “sandbox” where developers can test to make sure their integrations work correctly, but when this lands in production, logging calls/responses can help to find spontaneous errors or conditions that weren’t present in the sandbox. This basic form of logging enables you to walk backward and see what was requested and what was returned back at the instant it occurred. A service that intermittently returns a bad response or an unhandled error may be very difficult to trace, but log files can help simplify this into understanding what happened at the moment in time versus what the API may return now. In some situations, replaying an entire log file to validate the output of many calls can also be advantageous – for example, if there is a call per page through the course of a user’s entire session.  

Caching can also cause challenges in testing – be careful to avoid using cached responses from external APIs when running your test suite. Give consideration to how to handle error responses at cache time. For example, error cases may need to be tested more or less frequently, and whether these result in a billing event could shape your API testing strategy.

Overall benefits for using web-based APIs continue to advance, offering organizations increased functionality, flexibility and time/cost savings. Unlike some of the historical challenges with APIs, today’s web service-based approach can offer frustration-free integrations. Spending a few moments to build an API integration strategy can lead to outcomes faster and cheaper than the internal development of inferior services.

What are the issues that plague your API integration? Share with us on FacebookOpens a new window , TwitterOpens a new window , and LinkedInOpens a new window . We’d love to hear from you!

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Kevin Marcus
Kevin Marcus is the co-founder and CTO of Versium, a data technology company helping marketers identify, understand and reach their ideal customers. A serial entrepreneur, Kevin is a technical evangelist with 20 years of experience architecting highly scalable commerce and database systems. He is an advisory board member and alum of the University of California-Riverside.
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