I might be wrong here, but what if I change my settings to "not show the last seen status"? I guess in that case this doesn't work. Yes, I believe checking "Online" status frequently does give some information about my activity. Correct me if I'm wrong here.

I was thinking the same. I haven't seen any of my friend with last seen status enabled.

If you disable on your account, you can't see the last seen status of your friends, even if they have it enabled.

Could someone explain how this works? Meaning, I want to understand how the application uses the data from several MOOCs and get the result. Is that they manually build the data store and indexing on top of it? If so, what happens if a new course is added to the site? Link to source code would be really great, if you can provide one.

There is one point I need to add it here. Note that I'm not DB expert, but I need to say why I prefer Postgres over Mysql.

Create a table like the following:

create table user (name varchar(4));

MySql:

insert into user (name) values ('antoaravinth');

The above statement works even though I have given the size of my varchar as 4! And retrieving gives me `anto`!!

Postgres:

insert into user (name) values ('antoaravinth');

Stops me there with the relevant exception! That shows how Postgresql is doing small things right.

After seeing this, I never used MySql!

As said in many other comments: This is because you used MySQL in non strict mode. You don't run MySQL on Production in non strict mode.

As said in many other comments, the idea that there is even a "strict mode" which was not on by default for many years is itself a problem and a red flag for other problems.

Tell that to developers who develop with the default config and then expect that to work in "Production".

>I've used Postgres and Mongo pretty extensively, and for any reasonably seasoned developer, the startup overhead of an SQL system is a myth. There may upfront cost to learning how an RDMS and SQL work in the first place, but once you're familiar with them, they'll be faster than Mongo on any new project.

Exactly, I was very new to the RDBMS world and always I have preferred to go for MongoDB. Once in my side project, I thought of learning RDBMS and used Postgresql. Once I learnt how transactions, joins works then RDBMS was totally an easy topic.

I have used Jooq instead of ORM, which again helped me to learn the queries and underlying system of Postgresql!

I will be using using Play! , Jooq and Postgres. For front end, I'm going to use React.

>> Finally: don't use JWT. JWT terrifies me, and it terrifies all the crypto engineers I know. As a security standard, it is a series of own-goals foreseeable even 10 years ago based on the history of crypto standard vulnerabilities. Almost every application I've seen that uses JWT would be better off with simple bearer tokens.

This is really surprising to me. I use Play! framework and the whole play framework community suggests to use JWT for authentications as Play! doesn't support sessions out of the box. Is it just JWT itself is bad or how developers use it is bad? Just a noob question.

It is a standard for crypto created by non-crypto people. It is bad, don't use it. Using it correctly is harder than rolling your own stupid simple bearer token, which is very rare for standards. Using stateful authentication is even simpler. Using django or something like that is even simpler.

Service workers are really cool. I love them in using it in react project. In fact, create-react-app does inject a service worker for you to cache all the static files in production environment.

Nice article. Does anybody here tried Udemy (or other online course affiliate) affiliate? Any success stories for the same?

Just an average Udemy creator here, but maybe what I've learned is useful.

I started doing Linux tutorials on YouTube a few years ago ( http://youtube.com/c/tutorialinux ) and then created a course on Udemy about a year ago. Affiliates make a decent percentage there (75%) but I suspect they have the same frustration that I do: Udemy has sales EVERY FEW DAYS.

Every few days there are sales that offer 90% off all courses, $10 courses, etc. etc. So a course with a $200 price tag will have an average sale price of $10-15, which leaves everyone (including affiliates) with pretty slim margins.

The simple problem is that they have the power to re-price courses as they see fit, and an incentive to do so (Udemy gets 50% of the revenue, possibly more from their promotions).

As it is, I make about the same amount of money from YouTube revenue (40k subscribers) as I do with one of the highest-rated Linux courses on Udemy (a few hundred dollars a month). It's really just a blip next to my salary; I can't see it replacing full-time tech work anytime soon.

I would second what Dave said, and have you look at this front pager from yesterday: https://news.ycombinator.com/item?id=14711492

Yeah, I'm not sure why I haven't started running AdWords campaigns yet, but I need to get on that. I'll try that; thanks for the kick in the pants!

Thanks for your reply. That's an interesting stat. I have a question on:

>>>As it is, I make about the same amount of money from YouTube revenue (40k subscribers) as I do with one of the highest-rated Linux courses on Udemy (a few hundred dollars a month)

How do you promote your youtube videos?

At the moment, I don't actively promote videos except by notifying subscribers on YT, twitter, and occasionally facebook.

Others in this comment thread have convinced me to start actively promoting via e.g. Adwords, though. I'll start looking at that over the next few weeks.

Have you thought about self-hosting the course or using a platform like Teachable/Thinkific? Do you do any advertising?

My engineering instinct says, "I could build a simple little video-course platform in a weekend or two," but I know where that kind of thinking leads :-D.

More practically, I'm thinking about using something like Teachable for the next course.

OTOH at this point I've got content in a bunch of different places (YouTube, soundcloud, a website, udemy, packt/safaribooksonline), which makes leveraging all of these different platforms' features and supporting students there time-consuming.

Aside from work, hobbies, side projects, relationships, and other pesky human endeavors, I only have between 5-8 hours a week to work on tutoriaLinux. Adding another platform, with its own learning curve and features, seems like it might waste time that I could be investing into content.

I've actually spent a fair amount of time doing AdWords campaigns in the past, but I haven't done that for tutoriaLinux or the Udemy course yet. Maybe I should -- thanks!

Sorry, rambling.

Thanks for taking the time to reply. If you bring the customer to Udemy I think the cut is ~97% so definitely worth a try. Looks like you have a great platform on YouTube, I've subscribed. Best of luck!

May be you need to look into https://www.indiehackers.com. The site is great that it contains all the information / stories / ideas, about developers who sell their projects!

Thanks, will definitely drop an email to them.