Below I will mention the few changes and items added in the last 20 years in programming liguangens and their essence. I've noticed that the frontend has confused many and has given the misconception that those who know frontend programming already know how to program, which in my opinion is totally wrong. # <br>Programming languages and backend frameworks --- + **Evolution of languages**: Traditional languages such as Java, Python, Ruby and PHP have evolved, adding new features, improving performance and security. New languages such as Go and Rust have been introduced, bringing advantages such as simplified concurrency and memory safety. + **Backend frameworks**: The emergence of powerful frameworks such as Spring Boot (Java), Django and Flask (Python), Ruby on Rails (Ruby), Laravel (PHP), and Express (Node.js) has facilitated the rapid development of robust and scalable web applications. ## <br>2. Microservices and Architecture + **Monoliths vs. Microservices**: There has been a significant transition from monolithic architectures to microservices, where applications are divided into small independent services that communicate with each other. This improves scalability, maintenance and continuous deployment. + **Communication between Services**: Tools and protocols such as gRPC, RabbitMQ, Kafka and RESTful APIs have become standards for efficient communication between microservices. ## <br>3. Databases - **NoSQL**: The popularity of NoSQL databases such as MongoDB, Cassandra and Redis has grown, offering scalable and flexible alternatives to traditional relational databases. - **NewSQL**: New technologies such as CockroachDB and Google Spanner combine the advantages of SQL with the scalability of NoSQL systems. - **ORMs and Migration Tools**: The use of Object-Relational Mappers (ORMs) such as Hibernate (Java), SQLAlchemy (Python) and ActiveRecord (Ruby) has become commonplace, facilitating interaction with databases. ## <br>4. Backend security - **Authentication and Authorization**: Standards such as OAuth, JWT (JSON Web Tokens) and SAML are widely used for secure authentication and authorization. - **Security Practices**: Adoption of security practices such as input sanitization, encryption of data in transit and at rest, and use of web application firewalls (WAFs) to protect against common attacks. # <br>Essence of Logic in Programming --- ## <br>1. data structures and algorithms - **Data Structures**: Solid knowledge of arrays, linked lists, stacks, queues, trees, graphs and hash tables is essential. - **Algorithms**: Sorting algorithms (such as quicksort, mergesort), search algorithms (such as binary search), graph algorithms (such as Dijkstra, BFS, DFS), and dynamic programming techniques are crucial. ## <br>2. Programming paradigms - **Object-Oriented Programming (OOP)**: Concepts such as encapsulation, inheritance, polymorphism and composition remain central. - **Functional Programming**: Higher-order functions, immutability, purity of functions, and concepts such as map, reduce and filter are widely adopted. In summary, the frontend has changed more dramatically in the last 20 years compared to the backend. The evolution in the frontend includes a complete revolution in the technologies, tools and frameworks used to create interactive and dynamic user interfaces.