frontend technologies

html 5

css 3

vanilla JS

vue.JS

Angular

Webpack

Backend programming is a pretty broad term. It covers all the following application types and more:

• web applications that return HTML pages to the browser;
• mobile applications backend that open access to their JSON API via the HTTP protocol;
• microservices that interact with other microservices through RPC.

Java is still one of the most popular languages in Enterprise, and Kotlin is also gaining popularity, while being 100% compatible with Java. Spring can be considered one of the standards, despite the fact that there are other frameworks for building server-side business applications. Coordination of a distributed application leads to standard patterns and we can quickly build services and applications with Spring Cloud which implements those patterns.

JavaScript is a popular dynamic programming language that is used on both the client and server side. The Node.js framework is also popular in Enterprise development. Using TypeScript reduces the likelihood of errors in the code and also makes it easier to read through typing and interfaces. The NestJS framework is a powerful, flexible, feature rich framework based on Node.js. It uses JavaScript and TypeScript technologies and also allows you to connect many third-party services and libraries to the project.

Monitoring makes the system more reliable by increasing the transparency of what is happening to it. Timely response to problems quickly restores the system after crashes. Monitoring in Grafana provides many benefits: metrics visualization, creation and customization of dashboards, integration with various data sources, monitoring automation, performance optimization and more. One such data source could be Prometheus. This tool is responsible for collecting and storing metrics. The storage provided by Prometheus is fast and optimized, although not designed for long-term storage of a large number of metrics.

The Event Sourcing application architecture pattern is becoming more and more popular. Using Event Sourcing provides a complete log of all state changes ever made to an object making troubleshooting easier. We store all intermediate states as events instead of storing the final state. This provides application fault tolerance. Application rollback is reduced to rewinding the event log and reprocessing the data.

Kafka is a low-latency, high-performance, scalable and reliable logger. It's a natural foundation for storing events as you transition to an application architecture based on Event Sourcing.

The CQRS principle or paradigm separates the purpose of queries, such as Query of reading data and Commands for data processing. CQRS is an application architecture pattern most commonly used with Event Sourcing. We can choose different frameworks, programming languages, databases for Query and Command services. We could store / update data in a document-oriented database, and make queries in a relational database.

PostgreSQL is an object-relational database management system based on the SQL language, characterized by high reliability and good performance. The system is extensible - it is possible create your own data types and indexes, as well as extend the behavior using programming languages.

MongoDB is a document-based database management system. Belongs to the NoSQL class and is Schema-less. The system scales horizontally through the sharding mechanism and can work in a distributed mode. Replication is also supported - storing multiple copies of data.

ABOUT

Projects from idea to implementation, revision of current projects, changes to third-party projects, a project part implementation as part of third-party teams.

ANDREI DUDKO

Software engineer

9 year

Java, Kotlin, JavaScript, TypeScript