What an API is and why it is not just a technical matter
An API (Application Programming Interface) is the way two software systems talk to each other. When you fill in a form on Aliansa.rs and receive quotes from several insurers in one place — that is an API. When your online store automatically syncs stock levels with warehouse software — that is an API. Without API integrations, data is typed in by hand, errors multiply and working hours go into copying.
That is why an API is not just a technical topic: it decides how many people are needed to process orders, how quickly a client gets an answer and how many errors end up in invoices. A good test is to count how many times a week someone copies data from one program into another — every one of those places is a candidate for an integration.
The most common business cases for API integrations in Serbia
The most common business cases in Serbia: payment systems (NestPay, Corvus, Stripe for international transactions), email marketing (Mailchimp, Brevo — automatically adding customers from the site to a list), CRM systems (HubSpot, Pipedrive, local solutions), ERP and accounting software (orders from the site straight into bookkeeping and invoicing) and industry APIs (insurance, couriers, banking).
What an API integration looks like from the inside: your site sends an HTTP request with data to an external system, that system processes it and returns a response (usually JSON), and the site shows the result to the user. All of this takes a fraction of a second. The complexity is not in the principle but in the details: authentication, error handling, rate limits and testing edge cases.
What an API integration looks like from the inside — without technical jargon
The biggest risk is not the build itself but what happens afterwards: the external system changes its API version, an access key expires or the other side's server stops responding. A good integration therefore logs every error, retries failed requests and sends an alert when something fails — instead of silently stopping.
Cost, timeline, and risks of API development
The cost of a custom integration depends on complexity: a simple integration (for example a contact form into a CRM) is usually in the €500–1,500 range, moderately complex (payment system, email automation) €1,500–4,000, and a complex multi-system integration such as Aliansa with several insurers from €5,000 upward. Build time is one to six weeks, depending on the quality of the API provider's documentation and the number of systems.
When a custom integration is better than an off-the-shelf solution
A custom integration beats an off-the-shelf one when ready-made connectors (Zapier, Make) do not support your local system, when specific business logic is needed, or when transaction volume makes the monthly subscription more expensive than development. Feather Studio builds API integrations for insurance, e-commerce and B2B systems — see the Aliansa.rs case study or tell us which systems you want to connect.