So far, in our application, we’ve been following a pattern of controllers using services to access and modify the data. While it is a very valid approach, there are other possibilities to look into. NestJS suggests command-query responsibility segregation (CQRS). In this article, we look into this concept and implement it into our application. Instead of keeping […]
So far, in this series, we’ve used PostgreSQL to store data structured in columns. This approach has many benefits, but sometimes, we want some more flexibility, though. Chances are you already know JSON and use it in your web applications. There are databases like MongoDB that store JSON-like documents. With this approach, we can describe […]
There are quite a few things we can do when tackling our application’s performance. We sometimes can make our code faster and optimize the database queries. To make our API even more performant, we might want to completely avoid running some of the code. Accessing the data stored in the database is quite often time-consuming. […]
Redis is a fast and reliable key-value store. It keeps the data in its memory, although Redis, by default, writes the data to the file system at least every 2 seconds. In the previous part of this series, we’ve used a cache stored in our application’s memory. While it is simple and efficient, it has […]
So far, in this series, we’ve been creating an API that allows users to interact with our application. As soon as the client makes the request, we react to it and respond. Sometimes though, we need to delay the execution of some logic or do so on a schedule. A common solution in the Unix […]
With WebSockets, we can perform a two-way communication in real-time between the user and the server. Thanks to that, the browser can send messages to the server and listen to information from the other side. The principles of the WebSocket handshake WebSocket is a protocol that operates in a different way than HTTP. Even though […]
GraphQL has gained quite a lot of popularity lately. And no wonder, because it is an interesting approach to querying data. Therefore, it is definitely worth looking into. At its core, GraphQL is a query language with a runtime that can execute them. Although it is an alternative to REST, it can work alongside it. […]
In the previous article, we’ve implemented resolvers and queries. There is quite a common catch with them, though. It is referred to as the N + 1 problem. In this article, we illustrate the issue and provide a few ways to deal with it. The N + 1 problem The N + 1 problem can […]
So far, in this series, we’ve used GraphQL both to fetch and modify data. While this covers many real-life cases, modern applications often include situations in which users need immediate feedback when some event occurs. One of the solutions suggested by the GraphQL team is polling. In this technique, the client periodically requests the API for […]
With GraphQL, we model our API as a graph. Within a schema, we have various types of nodes that can relate to each other. While the fields in our query might have sub-fields, at some point, we want to work on concrete data. We refer to the type that describes an individual value as the […]
