Django Mock Interview | Interview Questions for Senior Django Developers

Summary

In this 2D Mark interview series, host Jose interviews software developer Andrew Espinoza for the role of an experienced Django developer. Andrew discusses his background in web and mobile development, highlighting projects like a 3D tourism website and a real-time delivery tracking system. The conversation delves into Django's architecture, middleware, caching, authentication, and ORM. Andrew also shares insights on Django's admin interface, mixins, and security practices, providing a comprehensive overview of Django's capabilities for developers.

Takeaways

• 😀 The interview is part of a 2D Mark interview series hosted by Jose, focusing on the role of an experienced Django developer.
• 🔍 The interviewee, Andrew Espinoza, is a software developer from Colombia with over five years of experience in web development and hybrid model development.
• 🛠 Andrew has worked with various technologies including JavaScript frameworks like Angular and React.js, Python frameworks like Django and Flask, and mobile development with Flutter.
• 🏆 Andrew has experience in fintech, healthcare, tourism, and other industries, developing robust and innovative solutions for various companies.
• 🌐 He has worked on projects such as a 3D website for a tourism claim using Three.js and a delivery company's software with real-time tracking capabilities.
• 🤔 The interview discusses middleware in Django, explaining its role in processing requests and responses within the application.
• 🏛 Django's architecture is based on the MVC pattern, with a template replacing the traditional controller role.
• 🔑 Django supports various caching methods, including memory caching, file system caching, and database caching, to improve performance.
• 🔒 Django offers built-in security features to protect against common threats like SQL injection, cross-site scripting, and cross-site request forgery.
• 🔄 Django's admin interface allows for quick development of a dashboard to manage application data, with customization options through plugins or templates.
• 🔄 Middleware is also used for authentication in Django, which can be easily integrated with other projects for authentication backends.

Q & A

What is the purpose of the interview with Andrew Espinoza?

The purpose of the interview is to discuss Andrew's experience and qualifications for the role of an experienced full-stack jungle developer.

What technologies has Andrew worked with in his career?

Andrew has worked with JavaScript, Angular, React.js, Python, Django, Flask, Flutter, and has experience in various industries including fintech, healthcare, tourism, and e-commerce.

Can you describe one of the projects Andrew mentioned during the interview?

One of the projects Andrew mentioned was a highly interactive 3D website for a tourism company that used Three.js to display a map of the region with attractions and points of interest using low poly models.

How did Andrew handle the data transfer from Python to Three.js in the 3D tourism project?

Data was fetched from the database by a Django script, which then called an API to download the models for display. The download included file compression, caching, and synchronous loading times to ensure a smooth user experience.

What is middleware in the context of Django?

Middleware in Django is a piece of logic that is executed every time a response is made to a request. It processes the request, performs necessary actions, and then serves the response.

Can you explain the Django architecture that Andrew discussed?

Django uses a modified version of the MVC (Model-View-Controller) pattern. Instead of a controller, it has a template. The model stores data, the view connects to the model and serves a template, which uses HTML, JavaScript, and Django's template engine to render data.

What are the different types of models in Django's model architecture?

Django has abstract base classes, multi-table models, and proxy models. Abstract base classes provide common information to child models, multi-table models allow each child to have their own database records, and proxy models allow cloning of a model and overriding its information.

How does caching work in Django?

Django offers various caching methods including memory caching, file system caching, and database caching. Memory caching is the fastest and most efficient, while file system caching stores cache files on the server, and database caching is useful for powerful databases with well-defined indexes.

What is the role of authentication in Django and can middleware be used for it?

Authentication in Django is used as a middleware. It manages user permissions and can be easily integrated into other projects. Django supports common hashing systems like bcrypt and sha256 for secure authentication.

Can Django be used as an API framework?

Yes, Django can be used as an API framework with the help of Django REST framework, which simplifies the development of APIs and provides powerful capabilities for API creation.

What are Django's supported databases and how can it be connected to non-supported databases like MongoDB?

Django supports major databases like PostgreSQL, MySQL, Oracle, and SQLite out of the box. For non-supported databases like MongoDB, third-party packages can be used. These packages need to be installed and configured in the settings.py file.

What are Django's field classes and what is their purpose?

Django's field classes are abstractions that define the structure of a database table, such as columns and data types. They are used in models to map database fields and ensure the correct data structure is used.

What is a mixin in the context of Django and the Django REST framework?

A mixin in Django is a type of inheritance that allows combining various pieces of code into one. In the context of the Django REST framework, mixins are used to quickly add functionality to views, such as CRUD operations.

What is the Django admin interface and how can it be customized?

The Django admin interface is a dashboard for managing data in applications. It can be customized by adding models and views to the admin.py file, using templates, or by adding JavaScript modules to customize functionality.

What are the best practices for security in Django?

Django has built-in protections against common threats, including SQL injection, cross-site scripting, and cross-site request forgery. Best practices also include enforcing SSL/HTTPS, session security, and proper input validation.

What is SQL injection and how can it be prevented in Django?

SQL injection is a vulnerability where an attacker can send SQL queries through an API request, potentially executing them on the server. Django prevents this by default through query escaping and sanitization, and developers can verify protection settings in the security section of the settings.py file.

Outlines

00:00

😀 Interview Introduction and Guest's Background

The video script begins with the host, Jose, introducing the 2D, Mark interview series and himself as the host for the day. He is joined by Andres, a software developer from Colombia with over five years of experience in web development and hybrid model development. Andres has worked with various technologies including JavaScript, Angular, React.js, Python, Django, Flask, and Flutter. He has experience in fintech, healthcare, tourism, and other industries, developing robust and innovative solutions.

05:01

🛠️ Discussion on Interesting Projects and Technical Implementations

Andres shares insights into two notable projects he has worked on. The first project involved creating a highly interactive 3D website for a tourism company, utilizing 3D models and a map to display attractions and points of interest. The second project was a comprehensive software for a delivery company that enabled real-time tracking of drivers and deliveries, utilizing Django's capabilities such as web sockets, REST API, and heightened security, with horizontal scaling on AWS cloud. The discussion also covers the technical process of passing data from Python to the JavaScript library, d3.js, for the 3D website.

10:02

🏛️ Exploring Django's Middleware, Architecture, and Caching

The conversation delves into the use of middleware in Django, which executes logic every time a response is made to a request. Andres explains Django's architecture, which is based on the MVC pattern but uses templates instead of controllers. He discusses various caching methods in Django, including memory caching, file system caching, local memory caching, and database caching, highlighting their use in a project with large 3D models. The summary also touches on authentication in Django, using middleware for this purpose, and the hashing systems employed for security.

15:02

🔌 Django's REST Framework, Admin Interface, and Security Practices

Andres explains the Django REST framework, which facilitates the development of APIs, and how it can be used to return different types of responses such as XML or JSON. He discusses the Django admin interface, which allows for quick development of a dashboard to manage application data, and how it can be customized using plugins or JavaScript modules. The summary also covers best practices for security in Django, including protection against common threats like SQL injection, cross-site scripting, and the importance of enforcing SSL and HTTPS.

🚀 Final Thoughts on SQL Injection and Closing Remarks

The final part of the script addresses the concept of SQL injection, a vulnerability where an attacker can send an SQL query through a request, potentially executing it if not properly protected. Andres explains the importance of escaping queries and mentions that Django has built-in protection against SQL injection. The host, Jose, thanks Andres for the interview and encourages viewers to apply for jobs on tooling.com if they have the relevant experience. He also invites viewers to follow the series on various social media platforms and subscribe to the channel for more content.

Keywords

💡Experienced Developer

An experienced developer refers to a software professional with a significant amount of time spent in the field, often with a deep understanding of various programming languages and frameworks. In the video, Andrew Espinoza is introduced as an experienced developer with over five years in web development, using technologies like Angular, React.js, Django, and Flask.

💡Frontend Development

Frontend development is the process of creating the user interface and user experience of a website or application. It involves using technologies such as HTML, CSS, and JavaScript. In the context of the video, Andrew has worked with JavaScript frameworks like Angular and React.js for frontend development.

💡Backend Development

Backend development pertains to the server-side of software applications, dealing with databases, logic, and server-side scripting. Andrew works with Python in the backend, utilizing frameworks like Django and Flask, which are pivotal for creating robust server-side applications.

💡Hybrid Model Development

Hybrid model development refers to the creation of applications that can function on multiple platforms, typically through a single codebase. Andrew has experience in hybrid development, having worked with Flutter to create applications for both Android and iOS.

💡Django

Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design. It is used to build web applications and is mentioned in the video as one of the frameworks Andrew has worked with, particularly for backend development.

💡Middleware

Middleware in the context of web development is a layer of software that connects an application's front end to its back end. In the video, middleware is discussed as a component in Django that executes logic every time a response is made to a request.

💡MVC Architecture

MVC stands for Model-View-Controller, a software architectural pattern used in developing user interfaces. Django uses a modified version of this pattern, as explained in the video, where the 'Controller' is replaced with a 'View' that serves a template.

💡Caching

Caching is a method used in computing to improve performance by storing copies of data, reducing the need to repeatedly fetch the same data from the original source. In the video, Andrew discusses various caching methods in Django, such as memory caching and file system caching.

💡Authentication

Authentication in computing is the process of verifying the identity of a user or device. It is a critical aspect of security for applications. The video mentions that Django uses middleware for authentication, supporting various hashing systems for secure user verification.

💡REST Framework

The Representational State Transfer (REST) framework is an architectural style for distributed systems, often used in the development of web services. Django REST framework, as mentioned in the video, is used for building APIs and supports various HTTP methods like GET, POST, PUT, DELETE, etc.

💡Django Admin Interface

The Django admin interface is a feature of Django that provides a quick and easy way to create an administrative dashboard for managing data within an application. It is customizable and can be adapted to fit the specific needs of the application, as discussed in the video.

💡SQL Injection

SQL injection is a type of security vulnerability where an attacker can insert or 'inject' malicious SQL queries into an input field for execution on the backend database. The video explains how Django protects against SQL injection by default, ensuring the security of applications.

Highlights

Introduction to the interview series with Jose as the host and Andres as the interviewee, focusing on Andres' experience as a full-stack developer.

Andres' background as a software developer from Colombia with over five years of experience in web and hybrid model development.

Andres' expertise in front-end development with JavaScript frameworks like Angular and React.js, and back-end development with Python using Django and Flask.

His experience in mobile development with Flutter for Android and iOS, and working across various industries such as fintech, healthcare, and tourism.

Description of a project involving a highly interactive 3D website for a tourism company using Three.js to display attractions and points of interest.

Another project mentioned is a full software for a delivery company with real-time tracking for drivers and deliveries, utilizing Django's capabilities.

Explanation of how data is passed from Python to Three.js in the 3D website project, involving API calls and data compression.

Discussion on middleware in Django, explaining its role in executing logic every time a response is made to a request.

Overview of the Django architecture, which uses a modified version of the MVC pattern with templates instead of controllers.

Different models in Django's style, including abstract base classes, multi-table models, and proxy models.

Caching strategies in Django, such as memory caching, file system caching, and database caching, and their respective use cases.

Authentication in Django as middleware, with support for common hashing systems and the ability to integrate with other projects.

Django as an API framework with the Django REST framework, allowing for easy development of APIs.

The response lifecycle in Django, detailing the process from HTTP request to HTTP response through middleware, views, and routers.

Databases supported by Django out of the box, including PostgreSQL, MySQL, Oracle, and SQLite, and the use of plugins for other databases.

Connecting Django to non-supported databases like MongoDB or Elasticsearch using third-party packages and the settings.py file.

Explanation of Django's field classes, which abstract database rows and allow for defining data types and relationships in models.

Experience with mixins in Django, which allow for combining various pieces of code into one for creating powerful API endpoints.

Overview of the Django admin interface, which provides a dashboard for managing application data and can be customized with templates or plugins.

Customizing functionalities in the Django admin by adding JavaScript modules or using plugins for specific features like filtering.

Best practices for security in Django, including protection against SQL injection, cross-site scripting, and enforcing SSL/HTTPS.

SQL injection explained and how Django prevents it by default through query escaping and sanitization.

Closing remarks with a call to action for developers to apply for jobs on tooling.com and follow the company on social media for updates.

Transcripts

foreign

we are back with another round of 2D

Mark interview series I am Jose and I

will be your host for today and today

I'm here with Andres that I'm going to

interview him for the role of an

experience paito jungle developer okay

uh and before we go I'd like to remind

you that the question that we are going

to be seeing today might be different if

you come to a touring interview because

this question was selected for a YouTube

purpose okay as that said let's get

started so first of all uh how are you

doing Andrews and how is your day doing

so far

hi Jose doing pretty good it's been a

pretty interesting day so I'm doing some

nice work nice so

um to guess that's these I would like to

ask you to introduce yourself and tell

me a little bit about your experience

okay use past projects and then I'll get

from there

sure so my name is Andrew Espinoza I'm

from Colombia I'm a software developer

with over five years of experience in

postdoc web development and hybrid model

development when it comes to front end

I've worked with JavaScript on

Frameworks like angular and react.js

back in development I work with python

with Frank was like Django and flask and

mobile developer and work with flutter

for hybrid development for both Android

and iOS I have experience in various

Industries like fintech Advocate

Healthcare tourism Majestic companies

developing robust and innovative

solutions to their problems and always

keeping in mind uh mobile and desktop

environments nice nice nice nice so uh

could you please let me know a few

interesting projects that you have been

work on

sure so a couple come to mind uh the

first one is a highly generated 3D

website that we did for a tourism claim

that use jungle in 3as to display this

map of the region that have all the

like I say attractions and points of

interest with low poly models and the

other one would be a full software for a

delivery company that allow for

real-time tracking of both the drivers

and their deliveries that use the full

Suite of what Django has to offer it had

web sockets RS API uh heightened

security and it was very able to be

horizontally scaled on AWS cloud

e3js which is a JavaScript library right

so uh I have a follow-up question for

that how would you pass data from python

to the d3js

so those were composed of two process

the first process was the view get from

the database the coordinates names

labels and some other information that

needed to display

on the template uh there was a script

that got all that information and called

an API in Django that downloaded the

models for display

this download had file compression it

had catching and it has a synchronous

loading times so

it wasn't a big paint it was just

everything would paint out as it was

loading the page

so that was how we did it with 3js

gotcha all right okay and so let me

let's now start talking about the jungle

okay uh

what is uh what's the use of midwares in

Jungle

so middleworth is a logic that is

executed every time you make a response

to a request to grab you or any other

API or any other point of your

application meaning that the user makes

a request then we got the information do

some processing and then we serve the

response that we get from The View

got you and could you please explain me

um let's see

could you please explain the jungle

architecture

sure Django uses a modified version of

the popular NPC pattern so instead of

having a controller we have a template

so our model stores the data we have the

view that connects to the model and it

serves a template which uses HTML

JavaScript and has the jungle template

engine to be able to render the data

that we get from The View right out of

the path

cool and what are the different module

in Huntington's style in Jungle

we have extra based classes which is a

parent that has all the information that

the child needs and we don't need to

write it again on the child we need we

have multi-table models which is sort of

similar but instead all the Childs have

their own records in the database and we

have proxy models which allow us to

basically clone a follower to our

children and we are able to override all

the information that we get from the

father of the children

okay great great and so yeah preview in

your previous answer you mentioned that

you work with caching right in your

application uh could you please explain

me uh the catch structured in Jungle

sure we got various methods of caching

uh we have name cache which is using the

memory that is in the server this one is

like the fastest and the most efficient

is the one we use with the project

because even though the models were low

poly there still had some pretty decent

size for a website there is file system

caching which is just storing our

caching files uh on the server local

memory caching which is the de facto one

that comes when you create your jungle

project

and we have database caching which is

good when you have a really nice

powerful database with very well-defined

indexes it can give you a better

performance that the other mentioned

want to go to and how would you explain

okay the authentication in Jungle and

also can we use middleware for that

yes basically authentication is used as

a middleware in Django right so we have

both authentication and authorization

so we can have users those users have

permissions those permissions could be

assigned to groups let's say that there

is an administrative group and a sales

group so they have their own set of

formation that is easier for the

developer to establish them Django has

the most common hashing systems that

there is nt5 and shot 256 we have four

validations and if we want to use Django

as a follow-on authentication backend

it's easy to Plug and Play to other

projects that may be used in other

languages okay and so we can use Django

as

API 2 right

yes all right there is a forum framework

it's called the West framework that

this is very easy to install and it

gives us four capabilities for

developing very simple and very powerful

apis nice and could you please explain

me

um say if you make a call to this API

then we it will return for us XML or a

Json or anything else right could you

please explain me the response life

cycle

sure so

you make a request right a Tango Korea

is an HTTP request object it loads the

settings.py file uh it checks that is if

there are middle words that need to be

wrong if there are we go through those

middle words and after that we go to the

router the router the size which one is

the view that is going to serve this

request it gets all the information if

the one meter works we get the

information that the middleware return

and we get to the view and eventually we

just get an HTTP response object that is

sent back to the client or the browser

okay great

um

all right so and what are the database

supported by jungle

so Django supports the Big databases the

patient must the standard right out of

the box we got postgres Maria MySQL

Oracle and SQL Lite

it also has plugins from Microsoft SQL

ID IBM sap

uh there may be some other packages that

are out there for

databases and officially Django doesn't

support any non-sql databases uh couch

face or something like

any other non-sql that not supported

officially all right and that's lead to

my next question how do we connect

Django to mongodb or Alexa search for

example

so if you go uh mongodb if you go to the

website they have the documentation for

the plugin that is for Django uh you

will install it through pip and then you

go to the settings.p1 file and it's

fairly easy to set up uh it's not bad

it's just that it's not officially

supported so you need to go through your

vendor first and they'll most likely

have the installation process for it but

it all comes down to there's a pay

package that you installed and then you

go to the settings.py file and you set

it up gotcha all right so and what is

jungle field classes or field class

so the field class is an abstraction of

what a row winner

database works like right so when we're

making our models and we're making our

Styles we need to add the columns to our

tables so this is how we will do so we

set up the data type be at bar chart

number Instagram Boolean whatever we

require if it's not if it's a primary or

a foreign key so on and so forth is

kind of this method that allows us to

map databases in general

cool and so

um

do you know what is some mixing do you

have experience work with mixings what

are mixings yeah uh I have plenty of

experience because mixing is kind of

like the big thing but you're using the

rest framework uh mixing is a type of

inherence that allows you to combine

various other pieces of code into one

code so talking about the rest framework

for example if you wanted to have very

quickly an endpoint that had get put

post patch and delete you add the mixing

for care take medicine for post the

mixing for the lead and the mix for both

and it out of the pad gives that

endpoint that view all the capabilities

that are required for it to be an API

okay uh and what do you understand about

jungle admin interface

so the admin interface is a way that you

cut very quickly and very easily develop

like a dashboard

to manage all the data in your

applications so when you create an app

when you go to the to the command line

to create an app you get an admin.py

file there you can add the models and

the views but you want to include in

that interface

from then you can either download a

template they're fairly easy and fairly

common you just go and search for them

for a template or you can create your

own template and you can specify what

template you want to check so that the

UI is

different from what the generic dangling

y has the power of the box

got you and so uh what what are the ways

the customize the functionalities

yeah sure what's the way that we can

customize functionality in the jungle

admin

so there are two ways like there's the

downloading a Plugin or template you go

into the settings.pr file there is a

section for admin and you add them there

and they're going to work right at the

path or

you can go into the root of your project

and there's going to be another naughty

and you can have JavaScript modules that

you can add them on a parameter that is

called Js

and then you will basically will be

adding or removing or changing

any functionality that you need uh for

example you need something along the

line so I need filtering and I'm

searching on the tables that are

displayed on the admin interface uh

there are plugins to do that or you can

Implement your own logic got you and

when it comes to security okay uh what

are the best practical practice in terms

of security in Jungle

so Django has by default enabled some

protection against very common threads

that it has SQL injection protection

which comes somebody evolve which is

very important to have cross-size

scripting if you're using an API and is

you're going to be using in a very

different environments such as mobile

and desktop there is cross-eyed request

ordering and other than that you

obviously it's very good to add the

ability to enforce SSL and https which

doesn't compound by default for

developing reasons you can add session

security when you're managing

authentications you can add clear

jacking protection and you can add whole

Square validation those are like

the standard that every project needs to

have

for it to be secure in production

cool and before I go to my next question

I would like to couple our developers

out there so if you have three plus

years of experience and are confident

with the skill set that you possess you

can head on tooling.com jobs and apply

for the job that is more suitable for

your Tech stack okay once you apply you

have to pass in the touring vetting

process and then once you pass you get a

job as we did okay also you can fall

into it on Instagram Facebook

LinkedIn YouTube uh Instagram what else

uh Twitter okay stay close that I'm

pretty much sure that you get the job

that you deserve okay

uh my last question for you uh Andres so

uh what is SQL injection okay and how

can we prevent SQL injection jungle

so SQL injections is a vulnerability

where your user on a four on a request

on an API called sends an SQL query and

there's not a protection for it and the

server and the backend actually executes

it and Returns the data that the

attacker wants to see so

the very basic simple SQL injection

protection is just what is called

escaping the queries which is just

formatting and sanitizing the test so

that it doesn't run anything that is it

be it if it was a query of a JavaScript

and Django actually takes care of this

by default but you can also check if the

protection is in place going to the

settings of the profile there's going to

be a security section and there should

be uh something on loading the SQL

injection nice all right thanks for

explaining so thank you Andrew again

that was really nice to speak to you

today and that that is all for today

okay uh and to everybody else thank you

for watching these videos in the pretty

much sure that you enjoyed this video as

I did okay uh you can write down message

and saying what kind of 2D Market if you

would see in the upcoming video okay

I've seen people commenting uh flutter

we are preparing for flutter okay what

else uh followed only getting YouTube

Instagram around Facebook Twitter a

clubhouse

YouTube any anywhere and as I said stay

close that you get the job that you

deserve okay uh don't forget to

subscribe to turin.com like this video

If you enjoyed the content let me know

in the comment section below uh if this

is uh similar that we're getting out

there uh as that said that's a wrap

thank you all thanks for watching and I

hope to see you all again okay take care

[Music]