Michał Dobrzanski MichalDanielDobrzanski

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

The introduction to Reactive Programming you've been missing

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

OAUTH2

The Problem

I’m a web app that wants to allow other web apps access to my users’ information, but I want to ensure that the user says it’s ok.

The Solution

I can’t trust the other web apps, so I must interact with my users directly. I’ll let them know that the other app is trying to get their info, and ask whether they want to grant that permission. Oauth defines a way to initiate that permission verification from the other app’s site so that the user experience is smooth. If the user grants permission, I issue an AuthToken to the other app which it can use to make requests for that user's info.

Note on encryption

Oauth2 has nothing to do with encryption -- it relies upon SSL to keep things (like the client app’s shared_secret) secure.

	@Composable
	fun ParallaxScreen(modifier: Modifier = Modifier) {
	val context = LocalContext.current
	val scope = rememberCoroutineScope()

	var data by remember { mutableStateOf<SensorData?>(null) }

	DisposableEffect(Unit) {
	val dataManager = SensorDataManager(context)
	dataManager.init()

	import 'package:flutter/material.dart';

	final Color darkBlue = Color.fromARGB(255, 18, 32, 47);

	void main() {
	runApp(MyApp());
	}

	class MyApp extends StatelessWidget {
	@override

	package com.filipkowicz.headeritemdecorator

	/*
	solution based on - based on Sevastyan answer on StackOverflow


	changes:
	- take to account views offsets
	- transformed to Kotlin
	- now works on viewHolders

	import java.io.IOException;
	import okhttp3.HttpUrl;
	import okhttp3.Interceptor;
	import okhttp3.OkHttpClient;
	import okhttp3.Request;

	/** An interceptor that allows runtime changes to the URL hostname. */
	public final class HostSelectionInterceptor implements Interceptor {
	private volatile String host;

	CREATE TABLE public.languages (
	id serial NOT NULL,
	code varchar(2) NOT NULL,
	"language" varchar(30),
	/* Keys */
	CONSTRAINT languages_pkey
	PRIMARY KEY (id)
	) WITH (
	OIDS = FALSE
	);