Backend engineering fundamentals and concepts

hi there, my name is Saad , these are basics concepts of whole backend engineering that every software developers need to understand instead of directly learning modern tool and framework if you understand these concepts then after pickup any framework language won't matter, but the only difference is all framework use different techniques and framework concepts but behind same engineering fundaments and concepts running. This blog is just for basic fast understanding, you need to explore more things in more detail by yours research.

PREREQUISITES

A high-level understanding
protocol(HTTPS,HTTP/2,HTTP/3,UDP,gRPC,FTP,WEBSOCKETS,TCP,QUIC,security layers(TLS,SSL) )
A high-level understanding
HTTP protocol
Routing
Serialisation and deserialisation
Authentication and authorization
Validation and transformation
Middlewares
Request context
Handlers, controllers and services
CRUD deepdive
RESTful architecture and best practices
Databases
Business logic layer (BLL)
Caching
Transactional emails
Task queuing and scheduling
Elasticsearch
Error handling
Config management
Logging, monitoring and observability
Graceful shutdown
Security
Scaling and performance
Concurrency and parallelism
Object storage and large files
Real-time backend systems
Testing and code quality
12 factor app(Codebase, Dependencies, Configuration, Backing Services, Build, Release, Run, Processes, Port Binding, Concurrency, Disposability, Dev/Prod Parity, Logs, Admin Processes.)
OpenAPI standards
Webhooks
Web Servers
How web servers work?
Dynamic vs Static Content
E-Tags
Relational vs NoSQL
ACID
Proxies (Reverse Proxies, Load balancer)
What is difference between Proxy vs Reverse Proxy?
Layer 7 Proxy vs Layer 4 Proxy
Reverse Proxy applications
Load Balancing algorithms
When to use Caching
Message queue, Pub/Sub
When to use PubSub messaging first queue.
Web Frameworks (API authoring)
Express, Django, Node JS
Message Formats (JSON, protobuf)
JSON & protobuf
Encryption,Firewall.