The goal of this final paper is to show the steps of development of web application.The development of every application, even the simplest one, is a long process that requires a lot of time, planning and work. This web application has gone through the process of making the idea itself, with the request being made, through the elaboration and creation of the first prototype, but has an open possibility of upgrading and further development. This paper presents a web application that allows the user to monitor production in mariculture and to order the item. The first step is to create a database. The base is grounded on a welldefined entity-relationship modelling. The key factors of a good entity-relationship modelling are the properly observed and implemented constraints. The important thing to which we have to pay attention is the assignment of roles and powers for individual roles. This enables database changes, but they can only be done by authorized users, most often by administrators. The next step is to create a web application and connect to a database. When developing a web application, we need to keep in mind the creation of web pages that are needed for the normal functioning of the application. In order for the pages to be made easier and visually transparent CSS, which defines the design of pages, was used. Microsoft Visual Studio 2015, programming language C# was used to create this web application.