[Renewed] Introduction to Python Backend and Web Technologies for Beginners (Intermediate Python, Understanding Backend and Web Technology Fundamentals with Flask) [Full-Stack Part 1-1]

This is a full-stack series aimed at beginners, with the goal of developing web and app services to a level that can be genuinely commercialized, based on real-world experience developing actual web services. As the first step (part1-1), this course provides an in-depth explanation of intermediate Python for full-scale development, backend implementation with Flask [플라스크], and essential web technologies such as HTTP, REST API, and the MVC pattern.

(4.9) 194 reviews

2,973 learners

Level Basic

Course period Unlimited

Python
Python
REST API
REST API
Flask
Flask
Python
Python
REST API
REST API
Flask
Flask

Reviews from Early Learners

4.9

5.0

dlclxkzk87

61% enrolled

I enjoyed the data analysis course so much that I decided to purchase the Flask course as well, and as expected, it was great because I could easily understand Flask's features through simple examples. However, if there is one minor thing I'd suggest, it would have been even better if the VS Code filenames were included in the Jupyter files. I plan to finish the backend by studying Full Stack Part 1-2 as well, and I will continue to work hard through the remaining lectures to become a developer capable of both data analysis and backend development. Thank you.

5.0

순수한햄스터

61% enrolled

Thanks to the lecture length not exceeding 20 minutes, I could quickly watch them before work. The explanations were kind and not too difficult, which helped me keep going without giving up!

5.0

JW P

82% enrolled

This seems to be the best lecture as a starting point for web development. Other lectures often missed the big picture, but this is a lecture that puts a lot of effort into conveying the big framework so that you can become familiar with the details through practice. If you've been swept away by trivial content and distanced yourself from web development, I recommend coming back to this lecture!

What you will gain after the course

  • Python Flask framework

  • Intermediate Python

  • Web Technology Basics

  • Computer Science Knowledge for Commercial Web Development

  • HTTP and REST API

The official course chosen for in-house training by top tech companies!

For beginners, this course will help you build a solid foundation in Python backend development and web technologies.

A high-quality lecture series (Full-Stack Part 1-1)

This course is part of a full-stack lecture series designed to teach the basics of Python back-end development and web technologies. It covers the intermediate Python syntax essential for developing professional skills, including object-oriented programming and first-class functions, as well as the fundamentals of Python back-end development and web technologies such as HTTP, based on the easiest framework, Flask. Therefore, it does not merely provide a brief explanation of how to use a framework, but explains all the essential background knowledge and related technologies you need to learn. Alongside working in the industry, I have developed this unique course with the learner’s perspective in mind as much as possible, drawing on 10 years of teaching experience with 100,000 students—making it unlike typical IT courses.

This course has been tried and tested by many learners, who have shared positive feedback. If any issues arise, it may be updated from time to time, as it is now.

This course was newly revamped in 2025 to reflect existing feedback.

This online course is designed for beginners, starting out very easily, gradually increasing in difficulty, and covering the core features step by step so that you can quickly learn how to use them. In contrast, this book is a reference book for experienced developers who want to consult Flask’s more detailed features.

Therefore, I recommend quickly reviewing and applying Flask’s core features through the online course, then using the following book as a reference book.

Flask & FastAPI for the fastest path to full-stack development, by Dave Lee of Janjaemi Coding

  I want to build a foundation in backend and full-stack technologies!

Whether for the web or mobile apps, modern services require backend, frontend, and deployment technologies to be built. This is what we call full-stack development, and if you're just getting started, learning each technology easily while building the whole thing will help you understand and apply web technologies comprehensively. As a first step toward this, the course is designed to help you understand backend technologies as quickly as possible, implement a feature used in the industry called A/B testing, and gain an overall understanding of and experience with full-stack technologies.


  Where should I start to learn full-stack technology?

After learning one programming language, try building REST APIs starting with the backend. The core of full-stack development is the backend. Python Flask is easy to learn, so you can quickly understand the backend and full-stack development as a whole.

In this course, you will learn backend technologies using Python Flask, make simple use of frontend technologies, and understand the overall structure of both the backend and frontend. In addition, it provides detailed explanations for understanding web technologies, intermediate Python syntax, and everything from planning (MVP) to the MVC pattern, covering the fundamentals needed to implement modern web technologies in detail.

I created a YouTube video summarizing the fastest and most comprehensive up-to-date full-stack roadmap. By referring to this video, you can understand not only this technology but also a roadmap for developing websites and apps on your own in a short amount of time.



 How much programming do I need to know to take this course?

This course, as well as the courses I create, is generally designed to be the easiest among courses covering the same technologies, so you can follow along step by step. However, since this course teaches backend fundamentals in depth using Python-based Flask, it will be much more effective once you have progressed beyond the beginner level, can program in Python, and have the ability to solve issues on your own through Google searches.

Build a solid foundation in core backend skills
Rather than simply learning how to use backend APIs,
we cover backend fundamentals and related technologies, as well as intermediate Python techniques!

 

In particular, this course is intended for those who are seriously preparing for a career as a developer. Accordingly, it also covers related technologies commonly used in backend development in depth. It covers intermediate Python syntax, as well as databases (SQL and the latest NoSQL), Python dictionaries (JSON format), and HTML.

Therefore, to significantly improve your satisfaction with and the effectiveness of the course, if you are not familiar with the relevant features and Python, we recommend taking this course along with the following three courses. (Based on years of feedback on the course structure above, we found that learners who took the introductory Python course first in sequence achieved much higher learning outcomes and satisfaction.)

* At the bottom of the detail page, we provide the fastest full-stack roadmap, which includes the three courses above. You can learn the entire web and app development process in the recommended order and step by step. By checking the roadmap detail page, you can understand the entire process at a high level, and if you purchase everything at once, it will be offered at a discounted price. (The discount rate will soon be reduced.)

 Would it be useful to learn backend technology with Python?

Recently, startups have been developing their businesses by quickly creating various services and then expanding the ones that receive the best customer response. Because Python offers excellent productivity, it can dramatically reduce the time and manpower required for service development. Generally, good developers can work with several languages besides their primary language, and Python has become a fundamental language that developers are expected to be able to use.

 
 

 What is Python backend Flask (Flask)?

Python Flask, along with Django, is a backend framework that uses the Python language. It is a technology widely used around the world, including by startups in recent years. Flask is easy to learn, enables rapid backend implementation, and is also suitable for learning essential web technologies. Django takes a long time to learn because of its distinctive framework usage.

Although Flask is easy to use, it can be difficult to find detailed information about it. In this course, we make extensive use of various Python Flask syntax so that you can firmly establish your fundamentals in Flask.


We also explain the overall concepts you need to know for web service development

In real-world web service development, you need a basic understanding of web service development as a whole, as well as knowledge of what you need to know for modern web service development. To that end, the course also covers web service planning and A/B testing, which I found necessary while working as a planner and developer in the field. It also explains the MVC pattern and HTTP protocol, which you need to understand as a foundation for implementing web services.

 

Don't waste time!
It's not that we can't do it because we lack information!
Learn with a proven course!


Can beginners do it too?

The most difficult IT course to teach is programming to people who know absolutely nothing about it. Even people like this have learned not only programming but also web scraping skills through the Python Basics and Web Scraping Fundamentals Bootcamp course I launched. If you approach it reasonably, it is more than possible. This course series is designed to help you gradually become familiar with all the skills needed at the introductory level, at an appropriate difficulty.

 

To ensure that even beginners can understand,
we provide the complete set of materials and code, organized even better than an e-book!
From relevant IT background knowledge and syntax to practice problems and detailed code
the materials alone make the course fee worthwhile.

 

Can I learn it systematically?

We create courses that guide you through the entire journey from beginner to full-stack developer, gradually increasing the difficulty so that you can learn in detail and systematically. To help you understand the relevant syntax and knowledge, we provide concise code and thorough explanations, while covering computer science concepts whenever necessary so that you can build the fundamentals needed to become a good developer.

It’s a course made with care so that you can feel, “Ah! It really is different!”


Learn systematically
Dave Lee’s Roadmap from Fun Coding

Following this course, a roadmap for AI, development, data, and CS that you can learn according to your goals giúp bạn học theo đúng mục tiêu.

IT technologies are interconnected.
By selectively learning connected technologies and adding AI to the mix, you can reach your goals much faster.

Every roadmap covers how to connect and use technologies together,
is designed to increase in difficulty from beginner to expert level, and
is continuously updated over the years.

It is also offered at a greater discount than when taking the courses individually.

3. Fundamentals of development and data, and core computer science (CS) knowledge

From computer architecture, operating systems, networks, system software, software engineering, and architecture to data structures and algorithms

← Swipe left or right to view the CS courses and the full roadmap →

View the full computer science roadmap in detail

4. The Most Reliable Ultimate AI Utilization Roadmap (2026)

From Claude Code-based work automation to vibe coding, Codex, OpenClaw, Claude Code-based data analysis, advanced Claude Code techniques such as agentic, harness, and loop engineering, and AI agent development.

← Swipe left and right to explore AI courses and reference programs →

View the Most Reliable and Powerful AI Utilization Roadmap (2026) in Detail

Recommended for
these people

Who is this course right for?

  • Those who want to develop their own web service

  • Those who want to become full-stack developers

  • Those who want to understand the backend as frontend developers

  • Those who want to build a solid foundation in backend development

Need to know before starting?

  • Python Basics

  • Database (SQL) Basics

Hello
This is funcoding

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4.9

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Courses

Janjemi Coding, Dave Lee

  • About Janjaemi Coding Introduction Blog [Click]

  • Key Experience: Coupang Senior Development Manager/Principal Product Manager, Samsung Electronics Development Manager (Approx. 15 years of experience)

  • Education: BA in Japanese Language and Literature, Korea University / MS in Computer Science, Yonsei University (A complete mix)

  • Key Development Experience: Samsung Pay, E-commerce Search Service, RTOS Compiler, Linux Kernel Patch for NAS

  • Books: Linux Kernel Programming, Understanding and Developing the Linux Operating System, IT Core Technologies That Anyone Can Easily Read and Understand, Python Programming Primer for Absolute Beginners

  • Operating Site: Fun-Coding (http://www.fun-coding.org) [Click]

  • This is a site that shares free materials related to full-stack development, data science, and AI.

  • Others: Fun-Coding YouTube Channel [Click]

    • I am starting little by little to share tips and short free lectures that are helpful for IT learning~

While working in the industry, I have been consistently creating solid full-stack, data science, and AI courses for 8 years.

 

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Curriculum

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62 lectures ∙ (13hr 53min)

Course Materials:

Lecture resources
Published: 
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Reviews

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194 reviews

4.9

194 reviews

  • wizproduct님의 프로필 이미지
    wizproduct

    Reviews 5

    Average Rating 5.0

    5

    80% enrolled

    I think this is the best lecture series for those who study alone. It wasn't easy to learn backend technology on my own, but after watching this lecture, I felt like I was reading the 'flask standard'. It's an oasis-like lecture with a mentoring-like feel, detailed explanations, focus on understanding, and abundant materials. If you think of time as money, It's much more cost-effective to learn this lecture and learn additionally than to struggle and learn alone from the beginning. At the beginning of this year, I started with the instructor's introduction to Python with a light heart. It was a year when I felt that I could make something with my own hands by listening to all the lectures step by step. Now, I'm thinking that I want to develop seriously. ㅎㅎㅎ This flask lecture is also difficult for me, but I'll absorb it quickly and make it mine. Thank you this year and I'll thank you in advance next year!

    • funcoding
      Instructor

      Thank you so much for starting with the crawling lecture. It gives me a lot of strength. Above all, I congratulate you for making progress and achieving results as a developer this year. Starting with Part 1 of Full Stack, the difficulty level is not easy, but it covers the parts necessary for full stack and the parts that a developer should have. If you understand that you need to go deeper sometimes and try it several times, it will help you steadily learn new technologies deeply. I hope this will help you become a good developer? A competitive developer. Thank you.

  • sogentle님의 프로필 이미지
    sogentle

    Reviews 11

    Average Rating 4.5

    5

    64% enrolled

    After taking a few classes, you can't help but become a fan of the instructor. He is so thorough, and his lectures are also very well prepared. I am such a fan that I even bought the basic lectures. But among them, after taking this course, I felt like my horizons were broadened, so if you have been interested in Python or websites, I definitely recommend it.

    • funcoding
      Instructor

      Thank you for leaving such a great review. It means a lot to me.

  • jdhwan2271587님의 프로필 이미지
    jdhwan2271587

    Reviews 1

    Average Rating 5.0

    5

    63% enrolled

    Hello teacher! Is it possible to skip FastAPI and only take the Flask course to go full stack??? My current company is operating a platform with Flask as the backend.

    • funcoding
      Instructor

      It is possible. However, since FastAPI has similar syntax to Flask while having some improved aspects, I think it would be good for you to organize and review it once in the future, even just for reference. Thank you!!

    • So would it be better to take FastAPI after Flask -> Frontend lectures??? My goal is to implement a full-stack service on my own later.

    • funcoding
      Instructor

      Sorry for the late response^^:; My apologies I think Flask and FastAPI have high correlation, so from a learning effectiveness perspective, Flask -> FastAPI -> Frontend would probably be better. If you learn FastAPI after getting familiar with Flask, you'll likely see many similar parts, so you'll get some repetition with Flask and be able to learn FastAPI quickly as well.

  • jwpark971147579님의 프로필 이미지
    jwpark971147579

    Reviews 1

    Average Rating 5.0

    5

    82% enrolled

    This seems to be the best lecture as a starting point for web development. Other lectures often missed the big picture, but this is a lecture that puts a lot of effort into conveying the big framework so that you can become familiar with the details through practice. If you've been swept away by trivial content and distanced yourself from web development, I recommend coming back to this lecture!

    • funcoding
      Instructor

      It's easy to get stuck in a small view and miss the broader scope, isn't it? I made it with that in mind, so I'm glad you noticed! Thank you😊

  • restful3님의 프로필 이미지
    restful3

    Reviews 21

    Average Rating 4.4

    4

    100% enrolled

    It's a good lecture. I'm more than 80% satisfied. The 20% who aren't satisfied... The lecture speed is slow in easy parts and fast in difficult parts. I had to keep adjusting the lecture speed in the browser. I think the speaker unconsciously speeds up in complicated parts. And it's not a fun coding, but a nagging coding. Haha. No matter how good the advice is, it doesn't seem good to repeat it too much. Except for these two things. I'm satisfied with everything. It's a good lecture. I recommend it.

    • funcoding
      Instructor

      I tried to keep the speed the same, but each person might have different difficulties... When I was listening to the lecture, I tried to cheer the students on, but they kept nagging me... Oh my, I'm glad you said it was a good lecture even in that kind of stance.

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