What Is API Integration: Benefits and Risks for Business

Think of a restaurant. You are the customer at the table and the kitchen is a separate system. The waiter is the go-between: he carries the order to the kitchen and brings the meal back to you. You never see inside the kitchen. You only know the form of order the waiter will accept. An API is the waiter of a program.

Programs do only two things this way: they ask for information or they send it. One program asks another what a given customer's latest order is, or tells it to record a particular order. The other side answers according to its rules. The document in which those rules are written is called the API documentation.

The most obvious gain is that repetitive manual work disappears. Entering the same information in two separate systems takes time and produces mistakes. Integration removes the double entry and keeps the information the same everywhere. Gathering the appointment records of a spa group's branches in one central place is a good illustration.

The second gain is that information stays current. If the stock figure differs between the sales channel and the warehouse, it is possible to sell an item you do not have. In an integrated system, when stock changes in one place it changes in the other. The third gain is scale: when the number of orders grows, a manual process is bound to collapse, while an automatic one grows with the same effort.

• Manual data entry and copy-and-paste work disappear.
• Stock, price and order information stay consistent across systems.
• Customers can be given live information on shipping, payment or booking status.
• Staff are freed from repetitive work and can attend to customers.
• Growth can be absorbed without extra staff.

The biggest risk is dependency. If the service you connect to changes its rules, retires a version or revises its pricing, the link on your side may stop working. For important integrations it is therefore worth looking at the provider's track record and at how current its documentation is. Where possible, consider a fallback for the critical flow, such as the ability to carry on by hand.

The second risk is security. An integration carries data between two systems, and that data may be customer or payment information. Access keys must be stored safely and only the permissions that are needed should be granted. For obligations around personal data it is sensible to consult a lawyer.

The first step in planning is to write down which information flows in which direction: where orders go from and to, where stock is updated, and which system is the master record. If the master record is not decided, the two systems overwrite each other's data.

The second step is to decide beforehand what happens when something fails. If the other system is down, the request should not be lost. It should be queued and tried again. The third step is monitoring: without a log and an alert showing whether the integration is working, a fault is noticed only when a customer complains. Testing the flow in a small trial environment before going live is also very useful at this stage.

The first mistake is trying to connect every system to every other. Each integration brings a maintenance burden, so choose those that really create value. The second is leaving error handling until later. The successful flow is easy. The real work is deciding what to do when two systems disagree.

The third mistake is leaving the documentation and the access details with one person. If the person who built the integration leaves and nobody knows how the link works, the first fault stops the business.

• Making needless connections: every integration needs continuing upkeep.
• Not planning for failure: it should be clear what happens when the other system is down.
• Skipping monitoring: a fault should be seen by you before it is seen by a customer.
• Storing keys in plain text: access details belong in a secure place.

If a piece of information is moved a few times a month, doing it by hand is often cheaper and more reliable. If the development and upkeep of the integration outweigh the time it saves, the investment is not worthwhile.

If a ready-made plug-in or built-in connection solves the problem, custom software is not required. For common needs such as payment and shipping, most platforms offer ready connections, and custom development makes sense only where there is a business rule the ready solution does not cover. The question to ask is whether the need is genuinely special.