Kafka's mechanism closely resembles that of the Robot Operating System (ROS), a prominent robot communication system. It is developed on the Java Virtual Machine and functions as a logbook, enabling users to view, pool, and manage data efficiently. Utilize Kafka to manage real-time price data from various global exchanges. This represents a prevalent and robust … Continue reading Kafka and Redis Add-on Explained by Gemini

What you view in others reflects who you are at your true self. If you perceive others as arrogant or self-bragging, it might indicate a deep desire within you to express those traits, yet something always inhibits you from doing so. Perhaps you admire their confidence and wish to embrace a similar authenticity, but societal … Continue reading Self-Awareness

JWT is for authorization, not authentication — Authentication checks credentials (e.g., username/password), while authorization ensures requests are made by the logged-in user. Traditional session-based authorization — User info is stored on the server; client sends a session ID via cookies with each request. JWT-based authorization — Server sends a signed JSON Web Token back to … Continue reading JWT Overview

The Singleton pattern is a way to guarantee that a class has only one instance throughout your entire application Factory Method pattern creates objects without specifying exact class. Abstract Factory Create families of related objects. Builder Construct complex objects step-by-step. Prototype Clone objects without depending on their class. Adapter Make incompatible interfaces work together. Decorator … Continue reading Common Design Patterns

S — Single Responsibility Principle (SRP) A class should have one job and only one reason to change. Below codes separate printer, saver to different classes class Report: def __init__(self, data): self.data = data class ReportPrinter: def print(self, report: Report): print(report.data) class ReportSaver: def save(self, report: Report, filename): with open(filename, 'w') as f: f.write(report.data) O … Continue reading SOLID Principle

Starting from Noether's theorem, the U(1) symmetry is associated with a conserved quantity, thereby necessitating its representation in an alternative formulation. Then we need to consider the complex field rather than scalar field, hence Then there is a leap on interpreting Q as charger operator or Number (of charges) operator.

Newton and Galileo never questioned that time is independent, but it is! Just need to think like Einstein! Setup Two identical light bulbs, A and B, are placed at equal distances on either side of a person standing still at the center on a train platform. The bulbs are programmed to flash at the same … Continue reading If Time Is Independent, There Is No Causality

One need to understand these basic concepts for system designing DNS: domain name system APIs has Restful and GraphQL two types CAP Theorem Websocket Webhook Monolithic Architecture versus Microservices Message Queues Elastic Search: stores data in JSON documents (kind of like a flexible NoSQL database); It builds a structure called an inverted index — think … Continue reading System Design Concepts

Very good lectures from "hello interview", sketching out the designing in below forms, Uber:

Redis (REmote DIctionary Server) is an in-memory data structure store, used as: A database; A cache; A message broker. It is known for ultra-low latency and high performance, often measured in microseconds. Let's build a tiny Redis clone in Python to understand the core mechanics of Redis. import socket import threading # In-memory key-value store … Continue reading Learn and Use Redis