News of Mail.Ru Group online courses on Stepik

Now the online courses “ Development in Java 1 ”, “ Development in Java 2 ” and “ Analysis of web projects security ” on the Stepik.org platform are freely available! We removed deadlines so that you can take courses at a convenient time and receive certificates. In the next ten days, we will restart two more online courses. "The formulation of tasks for software development " will open on October 28, and on November 3, " Web technologies " will become available.

Stepik.org is an online course platform. With it, you can learn something directly from home - you only need access to the Internet. The authors tell the material on video lectures and offer to perform practical tasks. Most courses are open only in the allotted time - this encourages indecisive participants to sign up. The course is divided into modules that need to pass on time. The presence of deadlines increases the motivation of students. Not all are doing well - on average, 9% of students receive certificates. Open access solves the problem of time, now only desire is needed.
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The first course from Mail.Ru Group opened on September 1, 2015. From this point on, 50,000 people have signed up to us, to whom we have issued 4,500 certificates. In February of this year, 8,500 people registered for “Web Technologies”. This is twice the average, so we want to talk about this course.

We created “Web-technologies” to introduce new programmers to the world of web and backend development in Python. In the course we are familiar with the schemes of servers. We emphasize the development of a backend using the Django framework. We also tell the basics of front-end development: html, css, js, and in additional chapters we discuss Ajax technology and the delivery of Real-Time messages.

Course assignments are different: in one place you choose the correct answer, in the other you enter it in a special field, in the third place you write a program. In the latter case, you implement a simple server, configure nginx to upload files, or perform another task using a virtual machine and a web terminal. When work on a task is completed, you run the tests. If the program passes them, the system puts points for successful execution. The time to perform such tasks is limited.

Tasks for programming are interrelated. Throughout the course, we step by step do the service of "Questions and Answers" - a simplified stack overflow. At the beginning, we configure nginx and gunicorn, then deploy a Django application, which we are gradually refining. We write models, add authorization checks and so on. In the course you need to install software, use git, program and configure web-servers. We will help you master some skills, but some of the topics will have to be studied independently.

The course takes a lot of time, especially for novice developers. Not everyone can withstand such a rhythm of work, and by the end the enthusiasm dies away. So, the first task for creating an echo-server was solved by 1,299 people, and one of the latter, for processing forms, was only 217. Yes, only 3,100 people out of 8,660 got to this task.

Here is an example of one of the tasks:

• develop a simple TCP echo server

Requirements:

• runs on the IP address 0.0.0.0 and TCP port 2222
• receives messages no longer than 1024 bytes and sends back to the client
• closes connection when receiving a message with the text close

With this formulation, the task is simple: open a socket, make a bind, make a accept in a loop, read 1024 bytes each, and if the 'close' line arrives, close the connection.

In the next task we ask to change the server:

• change your echo server so that it can work simultaneously with 10 clients
• The transfer protocol is the same as in the previous task.

To solve this problem, you need to process requests in parallel. In this case, difficulties arise even with how to properly close the connection . We do not limit the implementation of the server, fork or use streams to solve - one way or another, you will have to understand this topic. In practice, clients are thousands of times larger, and the server’s response is formed according to complex rules, but the backend developer must be able to solve such problems and understand how to work with sockets, processes and threads.

The first launch of the course took place in February 2016. Since then, 8,660 people have signed up for the course, to whom we have issued 507 certificates, 353 of them with honors. We hope that the course "Web-technologies" will help to join the world of the web. It doesn't matter if you want to take the position of a junior developer or better understand everyday life. Sign up!