Most organisations use several systems that each hold part of the picture: accounting, sales, inventory, payroll and customer communication. Integration connects them so information flows without being retyped. APIs are the most common way to do it.
What an API is
An application programming interface (API) is a defined way for one system to request information from, or send information to, another. Instead of a person exporting a spreadsheet and importing it elsewhere, the systems exchange data directly according to agreed rules.
Common integration tasks
- Creating an invoice automatically when an order is confirmed.
- Updating stock levels across a shop and a warehouse system.
- Sending customer details from a website form to a sales system.
- Pulling transactions into a reporting dashboard.
Questions to ask before integrating
- Does the system offer an API? Check the documentation, the features it covers and any limits.
- What permissions are needed? Use dedicated credentials with only the access required.
- Which system is the source of truth for each type of information?
- How fresh does the data need to be? Real time, hourly or daily?
- What happens when something fails?
Authentication and security
APIs usually require keys or tokens. Store them securely, never in public code or shared documents, rotate them periodically and revoke access when it is no longer needed. Use encrypted connections for all data exchange.
Plan for limits and errors
APIs often limit how many requests can be made in a period. Integrations should handle these limits, retry temporary failures sensibly and alert someone when a problem persists. Silent failures are the most dangerous kind, because data quietly stops matching.
Map the data carefully
Systems rarely describe information in exactly the same way. A customer in one system may be a “contact” or “account” in another, and fields may use different formats. Document how each field maps, and decide how to handle missing or invalid values.
Keep a record
Log what each integration sends and receives, at least in summary. Logs make it possible to answer questions such as “did this order reach the accounting system?” without guesswork.
When there is no API
Some systems offer only file exports, database access or nothing at all. Integration is still often possible through scheduled file exchange or other supported methods, but feasibility depends on the system and its terms of use.
Integration removes repetitive work and errors, but it also creates dependencies. Design it carefully, monitor it and assign an owner.
