IT Architect - Lesson 5 - Understand Application Architecture (Frontend/Backend)

Описание: hardware | network | distributed systems | application (frontend-backend) | DB

Goal:
Find the best way to organize your application code to be full-proof and future-ready.

Recommendation:
Code should be decoupled/organized by layers and modules.
Split your code by contexts/projects which are independent from each-other.
Create a structure that allows you scale horizontal and vertically.
Don't reinvent the wheel. Use libraries that already do what you need, libraries that are in the market for long time.

Structures:
monolithlic modular structure;
poliolithic modular structure with monolithic parts: all modules are independent from each-other and talk through brokers. This prepares your projects for microservices and allows horizontal and vertical scalability.
microservices structure;
...

Inside of each structure organize your code by Layers (this includes backend and frontend projects):
Presentation Layers (templates, views)
Routers Layers
Controller Layers
Logic/Service Layers
Data Access/Repository Layers
DTO/DAO Layers
Scripts Layers
Cronjobs Layers
Tests Layers
...

Notes:
Organize your code by independent projects with modules and sub-modules inside.
Java already has something similar with this structure where you can have multiple independent projects with multiple different versions, that call each-others, and almost ready for a full microservices structure.
Projects are independent: version, libs, manage, deploy, test units, integration testing, logs, monitoring
All modules should have test unit, integration testes, end-to-end tests, logs, monitoring, audit, failover logic
All projects should have code versioning (on git, svn...) with auto checks of code vulnerabilities and potential hacks.
add standards in code, similar structure to all your projects, same name conventions, everything in English.
Play attention on GC (Garbage Collector) and Heap memory leaks.

If you use React/Next/Angular/Vue.js on the Frontend - or similar techs:
Prepare your code for lazy load, breaking your JavaScript bundle into smaller chunks so the browser only downloads what it needs, when it needs it.
Make sure you are using the latest version of React. Versions released prior to December 2025 contain a critical security vulnerability in React Server Components (RSC) that could allow attackers to gain full shell access - CVE-2025-55182.