System Design and Architecture for Product Managers : Tech Every Product Manager Must Know !

Summary

This video script delves into the fundamentals of system design and architecture, particularly for Product Management Systems (PMS). It elucidates the three-tier architecture: the presentation layer (UI), the application layer (business logic), and the data layer (database). The script emphasizes the importance of 'separation of concerns,' ensuring that changes in one layer do not affect the others. It also covers scaling strategies, including the use of load balancers and stateless servers, and the critical role of databases and CDNs in maintaining user state and reducing latency. The discussion is aimed at enhancing product managers' technical acumen, equipping them with the knowledge to ask insightful questions and make informed decisions in tech-related discussions.

Takeaways

• 😀 Understanding system design and architecture is crucial for product managers (PMs) to build technical skills and set the right expectations with engineering teams.
• 🏛️ The three-tier architecture in software products consists of the presentation layer (UI), the application layer (business logic), and the data layer (database).
• 🌐 The presentation layer includes HTML, CSS, JavaScript, and jQuery, which are the front-end technologies that users interact with directly.
• 💡 The application layer is the backend where business logic resides, such as the criteria for user sign-up processes.
• 🔗 APIs (Application Programming Interfaces) enable communication between the presentation layer and the application layer.
• 🗄️ The data layer is where all user information and app data are stored, typically in databases.
• 🤝 The concept of 'separation of concerns' ensures that changes in one layer (e.g., business logic) do not affect the other layers (e.g., UI or database).
• 🌟 To scale a system, PMs must consider client-side applications, web servers, and databases, and how they handle increased loads.
• 🔄 Load balancers distribute user requests across multiple servers to prevent any single server from becoming overwhelmed, a key aspect of scaling.
• 🌐 CDNs (Content Delivery Networks) reduce latency by caching content in multiple geographically distributed servers, improving the user experience.
• 💾 Databases maintain the state of user interactions, ensuring that information like user sign-ups is consistent across different servers and sessions.
• 🔒 The importance of being stateless in web servers is emphasized, with the database and sometimes browser cookies being used to maintain user state.

Q & A

What are the three main layers of a software product?

The three main layers of a software product are the presentation layer, the application layer, and the data layer. The presentation layer includes UI elements like HTML, CSS, JavaScript, and jQuery. The application layer is the backend where business logic resides. The data layer is where all the information captured by the application is stored in a database.

How does the presentation layer communicate with the application layer?

The presentation layer communicates with the application layer via APIs (Application Programming Interfaces). APIs act as a bridge, allowing the front-end to request data or actions from the back-end.

What is the significance of the concept of separation of concerns in system design?

Separation of concerns is a design principle that separates a computer program into distinct sections. It ensures that changes in one layer, such as the business logic, do not affect the other layers, like the presentation or data layer. This leads to a more maintainable and scalable system.

Why is it important for a web server to be stateless?

Being stateless means that the server does not store any information about the user's state or data. This is important for scalability and reliability. It ensures that the server can handle requests without relying on stored state information, which can be maintained in a database or through cookies.

What is a load balancer and how does it help in scaling applications?

A load balancer is a system that distributes network traffic across multiple servers to ensure no single server gets overwhelmed. It helps in scaling applications by efficiently routing user requests to different servers, thus managing the load and improving the responsiveness of the application.

How does a CDN (Content Delivery Network) contribute to the performance of a web application?

A CDN is a network of geographically distributed servers that store copies of data, which allows for faster delivery of content to users. It reduces latency by serving data from the server closest to the user, thus improving the performance and user experience of the web application.

What is the role of a database in maintaining the state of a user in a web application?

The database maintains the state of a user by storing all the necessary information about the user, such as their sign-up details and preferences. This state information is crucial for personalization and ensuring that the user experience remains consistent across different interactions with the application.

How does sharding help in managing large databases?

Sharding is the process of breaking down a large database into smaller, more manageable sub-databases or shards. This helps in managing large databases by distributing the data and the load across multiple servers, which improves the performance and scalability of the database system.

What is an in-memory data store and why is it used?

An in-memory data store, such as Redis, is a data structure store that keeps data in the RAM for fast access. It is used to improve the performance of applications by allowing rapid data retrieval and manipulation, which is critical for tasks that require high-speed data access.

How does caching with Redis improve the response time of a web server?

Caching with Redis improves the response time of a web server by storing frequently accessed data in the RAM. When a request is made, the server can retrieve the data from the cache (if available) instead of querying the database, which is a slower operation. This results in faster response times for the user.

What is the full stack in the context of web applications?

The full stack in web applications refers to the complete set of technologies and components that are used to build and run a web application. It typically includes the client-side (presentation layer), the server-side (application layer), the database (data layer), and additional components like load balancers, CDNs, and in-memory data stores like Redis.

Outlines

00:00

💻 Basics of System Design and Architecture

The paragraph introduces the fundamental concepts of system design and architecture, particularly for Product Management Systems (PMS). It emphasizes the importance of technical skills for non-engineering professionals, highlighting the three-tier architecture of software products: the presentation layer (UI with HTML, CSS, JavaScript, etc.), the application layer (backend business logic), and the data layer (database storage). The concept of separation of concerns is discussed, explaining how changes in one layer should not affect the others, promoting modularity and maintainability in system design.

05:01

🌐 Scaling Systems with Load Balancers and State Management

This section delves into the challenges and solutions associated with scaling systems, such as handling an increase from 10,000 to one lakh users. It introduces load balancers, which distribute user requests across multiple servers to prevent any single server from becoming overwhelmed. The importance of state management is discussed, explaining how user states are maintained in databases to ensure consistency across different servers. The concept of stateless servers is introduced, with databases and cookies mentioned as methods for state storage, emphasizing the database as the single source of truth.

10:01

🔥 Handling Failures and Data Integrity with CDNs and Sharding

The paragraph addresses the issue of data center failures and how systems can maintain data integrity and availability. It introduces the concept of database clustering and Content Delivery Networks (CDNs), which shard data across multiple databases to prevent data loss and improve access speeds. The use of CDNs is explained as a way to reduce latency by geographically distributing servers, ensuring faster content delivery to users. Additionally, the paragraph touches on in-memory data stores like Redis, which serve as fast caches for retrieving information.

15:05

🚀 Full Stack Overview and PM's Technical Understanding

The final paragraph provides a comprehensive overview of the full stack, from the client-side application to the web server, CDN, and database, illustrating how a message sent on WhatsApp travels through this stack. It emphasizes the importance of product managers having a solid understanding of these technical concepts to effectively communicate with technical teams. The paragraph concludes by suggesting that while these concepts are essential for a PM's knowledge base, they may not directly impact day-to-day operations but are crucial for asking the right questions in a technical context.

Keywords

💡System Design

System design refers to the process of planning and compounding a set of components to achieve a particular functionality in a computer program or system. In the context of the video, system design is crucial for product managers to understand, as it involves creating a blueprint for how different parts of a software system will interact. The video emphasizes the importance of system design for PMs to build technical skills and set the technical bar for product development.

💡Architecture

Architecture in software development denotes the structure or blueprint of a system, including its components, their relationships, and the principles guiding their design and evolution. The video discusses the three-tier architecture, which is a common pattern used in system design, consisting of the presentation layer, application layer, and data layer.

💡Three-Tier Architecture

Three-tier architecture is a design pattern where the system is divided into three logical layers: the presentation layer, the application layer, and the data layer. This separation allows for a clean division of concerns, making the system easier to manage, scale, and maintain. The video explains that each layer has a distinct role, with the presentation layer handling user interface, the application layer processing business logic, and the data layer managing data storage.

💡Presentation Layer

The presentation layer is the topmost layer of the three-tier architecture and is responsible for the user interface. It includes technologies like HTML, CSS, JavaScript, and jQuery that define how users interact with the application. In the video, the presentation layer is described as the first point of contact for users, where the UI of an app resides.

💡Application Layer

The application layer, also known as the middle layer, is where the business logic of the system is processed. It acts as an intermediary between the presentation layer and the data layer, handling tasks such as user authentication, data processing, and business rules. The video uses the example of a sign-up process on an e-commerce platform to illustrate the role of the application layer.

💡Data Layer

The data layer is the bottom layer of the three-tier architecture and is responsible for data storage and retrieval. It interacts with databases and ensures that the information captured by the application is stored and managed effectively. The video emphasizes that the data layer is crucial for maintaining the state of user data across different interactions with the application.

💡APIs

APIs, or Application Programming Interfaces, are sets of routines, protocols, and tools for building software applications. They allow different software components to communicate with each other. In the video, APIs are mentioned as the means by which the presentation layer communicates with the application layer, facilitating the exchange of data and commands between the user interface and the business logic.

💡Separation of Concerns

Separation of concerns is a design principle that involves separating a computer program into distinct sections, each addressing a separate concern. This principle is crucial for maintaining a system's modularity and making it easier to understand, develop, and test. The video explains that changes in one layer, such as the business logic, should not necessitate changes in other layers, like the presentation or data layer.

💡Scalability

Scalability refers to a system's ability to handle growth, either in terms of the number of users or the amount of data being processed. The video discusses the importance of scalability in system design, especially when anticipating an increase in user traffic. It mentions the use of multiple servers and load balancers to distribute the load and ensure the system can handle a growing number of requests.

💡Load Balancer

A load balancer is a networking component that distributes network or application traffic across multiple servers. It is used to ensure no single server bears too much load, which can lead to decreased performance. In the video, the load balancer is described as a critical component in a scalable system, directing user requests to different servers to prevent any single server from becoming overwhelmed.

💡Stateless

Being stateless in the context of web servers means that the server does not store any information about the user's session or data. Instead, this information is stored in a central database or through other means like cookies. The video explains the importance of statelessness for scalability and maintaining user state across multiple server interactions, with the database serving as the single source of truth for user data.

💡CDN

A Content Delivery Network (CDN) is a system of distributed servers that deliver web content to users based on their geographic location, so the content is served from the nearest server. This reduces latency and improves load times for users. The video discusses the use of CDNs to enhance the performance of web applications by caching content closer to the user and distributing the load across multiple servers.

💡Redis

Redis is an in-memory data structure store used as a database, cache, and message broker. It allows for fast data retrieval and is often used in high-performance applications. In the video, Redis is mentioned as a tool for caching data in memory, which can be quickly accessed by the application to improve response times and reduce the load on the database.

Highlights

Introduction to system design and architecture basics for Product Management Systems (PMS).

Importance of technical skills for non-engineering backgrounds in product management.

Explanation of the three-tier architecture in software products: presentation, application, and data layers.

The role of HTML, CSS, JavaScript, and jQuery in the presentation layer.

The application layer as the backend where business logic resides.

Communication between presentation and application layers via APIs.

The data layer's function in storing app information and capturing user data.

Concept of separation of concerns in system design to maintain modularity.

How changes in one layer should not affect the others due to separation of concerns.

The necessity of scaling systems and the components involved: client side, web server, and database.

Use of load balancers to distribute user requests across multiple servers.

The importance of maintaining state and how databases serve this function.

The concept of being stateless in web servers and stateful in databases.

Handling user state across multiple servers through database and cookies.

Strategies for data redundancy and disaster recovery with database clusters and CDNs.

The role of CDNs in reducing latency and improving content delivery speed.

Use of in-memory data stores like Redis for fast data retrieval.

The full stack architecture from client to database and the importance for product managers to understand it.

Transcripts

now we will talk a little bit about the

basics of something called system design

and architecture for PMS let's talk

about the basics of system design and

architecture for PMS now for all of us

who come from product management and

non-engineering background it is

important to understand to build our

technical skills sometimes knowing the

technical bar for PM starts and it is

the easiest part okay so there are three

is there is a three tier architecture in

a software product consists of number

one is called presentation layer second

is called application layer third is

called the data layer presentation layer

is typically the UI layer what I mean by

UI is HTML CSS JavaScript jQuery they

all come in the presentation layer the

first layer the any UI that you see on

the app is called as the presentation

layer second is called the application

layer application layer is the backend

where the business resides now the back

end where it resides the presentation

layer can communicate to the application

layer via apis and we'll talk about what

an API is right and the third layer is

the data layer where all the information

of a particular app or or whatever

information that you capture that gets

stored in the database now is this clear

there are three types of layers in any

system the first layer is called the

presentation layer the UI layer where

HTML CSS JavaScript jQuery they all

resides they it is separate it's the

first layer the second layer is called

the application layer which is basically

where the business logic resides and

there any logic like for example you are

typically signing up on flip cart what

are the different criteria for somebody

to sign up to give email to give phone

number Etc all of those logic resides in

the application layer and the last layer

is the database layer where somebody who

has signed up the information of all of

that particular user gets stored in the

database now these three layers are

there is a concept which is called

separation of concerns it's a design

principle for separating a computer

program into distinct sections like

sections separation of concerns for

example let's assume like bus logic

change so it doesn't mean that the

presentation layer will also change for

example if you go to Flipkart as a

website the presentation layer shows the

signup form right now in the application

layer you change the logic and say that

now I don't require email ID and it is

optional if you change the logic in the

application layer it should not affect

the presentation layer nor it should

affect the data layer this concept is

called separations of concerns like for

example changing the user interface

should not change the business logic and

vice versa to separation of concerns

think of it as three different types of

systems let me just quickly share my

screen and tell you what I'm talking

about so first is presentation layer UI

layer second is application layer

business logic third is data layer data

to be captured now if I make any change

change here it should not change the

logic logic remains same logic remains

same if I make any change

here logic remains same logic remains

same so by changing the logic in any of

the three layers right it should not

affect the other two layers that is

something that is called as separation

of concerns separation of concerns

basically means any change in any of the

three layers does not affect the

remaining

layers amazing amazing now next

step UI layer application layer data

layer the next next step is to scale

right in order to scale you need two

three things one the client side second

client basically means the app that

you're using second the web server and

simultaneously the data database like

for

example user 1,000 say we scale to

10,000 so it should not happen that when

people are hitting your client or when

people are using your app the web web

server the web on which the application

logic resides it should get overwhelmed

absolutely so what you typically do is

you create a list of servers the logic

is that the your all of your

presentation layer resides on the

application that you're using like

WhatsApp that you're using right now

anybody who sends a message on WhatsApp

it goes to the web server right and we

have created a server logic any message

that should go on WhatsApp from one

person it should eventually go to the

web server and eventually it should

reach

towards the other client Cent right now

but what happens if tomorrow you scale

from 10,000 users to one lakh users

right there in that case you typically

create a list of servers list of

multiple servers and these servers are

typically routed to different servers

through this concept called a load

balancer right like for example I'll

quickly share my screen again now here

what will happen is your web server is

your backend number of users 10 if we

scale the number of users to 10 million

we will not need just one web server we

will need web server one web server two

web server three and what will happen is

here we there will come a load balancer

load balancer will automatically send 5

lakh ,000 users to one server 40,000

users to another server 10,000 users to

another

server and this is what a load balance

answer does so in the case when you have

multiple people on the servers you

typically need something called a loads

load balancer to direct traffic direct

traffic and and it will handle a

fraction multiple user multiple servers

will have multiple types of loads right

so now you have a cluster of web servers

through and applic application server is

basically the web server only but each

request that comes from a user may be

routed to a different server right now

what will happen now the question is

that if different requests are routing

to different servers how will a server

like for example server one server one

got a request that Shan is a user now

next time Shan sends a request the

request goes to server two how will

server two know that s Shan is already a

user give me a sense give me a yes or no

how will server two know that Shan has

sent already a request and it is already

on server one so that think there are

100 requests that are going Shan

initially sent a request which went to

server one and server one got it

validated now the second part that next

time Shan sends a request it goes to

server two how will server two know that

Shan has already sent a request to

server one so in this case what you do

is your database maintains the state do

you understand what I mean by that so

there are three layers first is

application layer second is the server

layer third is the DB layer yes so

server two will a absolutely absolutely

servers can talk to each other or there

can be a possibility that your state of

signup is maintained in the DB so even

if the server two does not know it

automatically takes information from the

DB and understands that Shan is already

a user for this particular application

for flip cart right and so what do you

learn from this you learn that the state

of a particular user can only be

maintained in a DB yes absolutely

correct so what is so again I'm

repeating you start from let's assume

you were a user for Flipkart you signed

up a request server one recognized that

you have signed up next time when you

sign up it goes to server two server two

does not know but server two knows that

your state that you are already a signed

up user already resides in the DB it

will go to the DB and bring information

from the DB and automatically can

showcase it to the client and you will

be signed up The Importance of Being

stateless State basically means ensuring

that the state that the value prop or

the data is already covered The

Importance of Being stateless primarily

refers to the server side of things the

database is an appropriate state where

you can maintain the the database is the

appropriate place to maintain the state

and most holistic statements uh holistic

systems are stateful otherwise you would

not be able to to fill your shopping

cart at Amazon because at every page

click it will forget who you are so the

key to being stateless in the web server

which is serving your apis two places

are there where you can maintain the

state maintain the state the first place

is called the database so that you are

maintaining all your status States in a

particular database the first part is

that in order to maintain the state the

information is located in the server the

second place where you can maintain a

state is through browser via cookies lot

of times you see that when you sign up

in a in Chrome browser automatically the

URLs are already published because your

information is getting stored in a

cookie it is important to remember that

cookies are not the single source of

Truth cookies are user dependent so the

best way to store the state is in a DB

which is a single source of Truth in

order to maintain the state that's why

all of these companies why are why do

these companies like flipcart Amazon

want you to sign up every time because

they want to maintain your state in a

particular DB they don't want guest

users ideally any company like Flipkart

Amazon do not want guest users they want

to maintain your state in a

DB

awesome awesome now another thing that

you want to understand is you can handle

a bunch of request but what if your data

center catches

fire what does

happen in case in that case what do you

do what if your you you sent a request

your your states are maintained in a DB

but what if your data center catches

fire what will happen

then yes absolutely so what you

typically do is you create a cluster of

databases right and in order to maintain

that cluster of databases you also use

something called as a CDN or a Content

delivery Network which basically means

that your information is sharded into

multiple databases and a CDN is a

cluster of servers which maintains

certain certain little little

information so you want to what if and

that is something that you do in a

process which is typically called as

sharding which is which is you break

down the current database also into sub

databases and the sub databases maintain

a replica of information which is

currently needed absolutely Absolut

absolutely is this clear to you guys

that what if your data center catches

where in that case you have created sub

DBS which are called DB shards in which

your information is fundamentally

retained another thing that you want to

understand is okay now your database and

everything is working fine for example

if your DB is located in Oregon in us

and you are putting from Mumbai it will

take a lot of time for the request to

get covered the request to get covered

so in order to for us to make the

request basically a request from the

Flipkart application to actually the

user if in order to make it very very

simple you use something called as a CDN

a Content delivery Network which

basically means that your current server

is not exactly a single server it is a

list of multiple servers one located in

Mumbai one located in Oregon one located

in uh Chennai one located in Delhi right

so that from where the user is sending a

request the information can be brought

very very fast

and this is done by CDN CDN are of

multiple times Amazon has its own CDN

Tata has its own CDN multiple so CDN is

a cluster of servers cluster of network

servers which minimize the latency of a

user from where the user is actually

sending a

request the next thing that you have to

understand is a CDN is a system of

geographically located servers which

provide fast and Fast Delivery of

Internet content does does

that what is a CDN give me a yes or no

guys if everybody a CDN is a network of

geographically located distributed

servers that work to together to give

you the delivery of the fast content

right what is the CDN besides the CDN we

also retain information in the cach a

cach a is in in memory data what I mean

by inmemory data is that like there is a

ram there's a Rome right in a typical

computer there's Random Access Memory

there's readon memory RAM is something

which is in which which is in memory

which is stored on the computer and they

it is very less it's very very expensive

and it is where the maximum the most

important tasks are done by the computer

like lot of times when you take a Mac

you say 8 GB Ram is Sir 256 GB R in that

case there is another structure an open

source inmemory data store which is

called redis on which all the

information is actually stored and

information can be retrieved first lot

of times you hear this word called redis

cache redis is again it's a inmemory

data store which is used in order to

retrieve information from the from from

the ram of the particular web server

that you're looking at think of it like

this I will again create an architecture

client on top client sends a request to

web server web server CDN it will go it

the request go to the nearest CDN just

between these two there is redis Major

important information comes from redis

now think of it like this the client

sent a request it went to the redis

cache if the redis cash has the request

the information will go from there only

or else it will go to the web server the

web server will automatically choose the

load balancer or the low distributor

will automatically figure out which is

the nearest web server and the

information from that will be

distributed back to the client and you

see a WhatsApp

message so think of it I will repeat

again you are using Whatsapp WhatsApp

message

message red

cach whether that information is already

stored in the cach if it's in the cach

the information will be retrieved from

redis it will go to the web server web

server automatically the load balancer

will automatically figure out which is

the closest web server on which the

logic can be put across it will then go

to the CDN the CDN will talk to the

DB and your message which you

sent will go to Uno will go to the other

partner the other partner the full

stack client web server CDN and database

this is typically called as a full

stack amazing amazing amazing now what

you have to

understand these are like primarily

relevant for you to understand as a PM

this will never come in real

life this is all to understand basically

what a PM does right now but based on

this understanding these are some of the

questions that a PM should ask when

they're interacting with

tech

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