What Business Central Integration Concepts Should Freshers Understand for Developer Interviews?

A fresher preparing for a Business Central developer interview should understand integration as more than simply “calling an API.” The interviewer is usually looking for whether you understand how Business Central communicates with external applications, which integration mechanism to choose, and how to design the integration safely and maintainably. Start with the core integration options. Business Central supports REST APIs, OData and SOAP web services, while Microsoft recommends the REST API stack for most integrations. Business Central also provides standard APIs and allows developers to create custom APIs using API pages and API queries. A good fresher should be comfortable explaining a scenario such as: External Application → REST API → Business Central → Business Data For example, imagine an e-commerce application sending a new customer and order into Business Central. You should be able to discuss: Authentication and authorization API endpoints HTTP methods such as GET, POST, PATCH and DELETE JSON request/response structures Company/environment context Standard APIs versus custom APIs Error handling and validation Pagination and filtering API performance Integration monitoring and retry strategy You should also understand AL events. Events allow extensions to react to application behaviour without modifying the original application code, which is important for upgrade-friendly development. Business Central includes business events, integration events, global events and trigger events. A practical interview scenario Suppose an external CRM creates a customer and Business Central should automatically receive it. Don't answer only: “I will create an API and insert the customer.” A stronger answer would be: “First I would check whether the standard Business Central API already supports the required scenario. If it does, I would prefer the standard API rather than creating unnecessary custom functionality. If the business requirement isn't covered, I would consider a custom API page/API query. I would then design authentication, validation, error handling, idempotency and monitoring, and keep custom behaviour isolated through extensions and events where appropriate.” That answer demonstrates architecture thinking, not just AL syntax. What should you practise? Build a small project where: External .NET API → Business Central REST API → Customer creation → Response/Error handling Then extend it with: Business Central → external API → event-driven notification That single project can help you practise AL, APIs, JSON, authentication, events, debugging and integration architecture. Microsoft also provides a dedicated learning path covering Business Central web services, REST services, APIs, Azure Functions and other integration approaches. Career tip: Don't prepare for a Business Central interview by memorising AL syntax alone. Learn to explain why a particular integration approach is appropriate for a particular business requirement.