How I built SQL course for Product Managers, Marketers and Data Analysts
It’s been a little over a year since SQL Habit was launched. 
It started so great – first users trying the course, first users buying the full access and sharing amazing feedback.
Then COVID happened and many other dark things. I’m so glad that among all that I had a safe space, a lighthouse that would always brighten the way – SQL Habit. 
I’m really glad to share this Q&A post, a collection of answers/histories/recipes I’ve collected over the past year. Enjoy and don’t hesitate to ask for more. 
Vision 
“Awesome idea! Would love to know more about your vision for the product when you started vs during building it vs now. Sort of a before/during/after — speaking about different pivots and about what’s next.”
Before. I think the main pivot was in the very beginning. The idea of SQL Habit was originally to make my team at work more data-savvy. A teeny-tiny pet project.
While thinking about a prototype I realized that it could be a much bigger project. Like “I should share my experience with the whole world” kind of projects. This is how SQL Habit got started. 
During. After the first half of the course was finished I got some unexpected feedback: the course helped some students to prepare for job interviews (and successfully land these jobs ). The imaginary student I keep talking to when writing new lessons is not a job seeker. She’s rather a marketer or PM who wants to be able to answer any question with data. 
That inspired the format of Mock Interviews where you solve challenges to prepare for a job interview.
What’s next. Lately, I’ve been hearing from students that they don’t know where to apply for a new job. I still see that the majority of companies don’t have data-transparency and not all employees can access a company’s data. That inspired me to start building the Job board (coming in 2021): a job board where every position implies data-transparency and high standards of working with data.
I want to make sure that every student on SQL Habit can easily find a new job or an internship to continue on their path of becoming data professionals. 
“Does your course have an in-person/live component?”
It used to have, yep. For 5 months I was doing live workshops with students. It was extremely fun, talking with people from all over the world, helping them out with questions at work and solving data challenges together.
I noticed that the most valuable part of these workshops was me sharing my screen and going over data challenges. This inspired a new format – Screencasts and I’m slowly building a home studio and recording videos. It’ll be live in 2021. I can’t wait tbh, this is so exciting (and extremely hard because I had no experience producing anything).
“What is your unique selling point? There are lots of SQL courses out there.”
SQL Habit teaches 20% SQL and 80% domain knowledge and skills required to apply it at work. SQL, in the end, is just a language to talk to a database.
SQL Habit is a course that helps Marketers, Product Managers and Data Analysts to develop skills to extract actionable insights from data.
“Were there any changes in the approach to teaching/materials in the course?”
The biggest change was that in the course to solve an exercise you need to calculate some metric, like ARPU (Average Revenue Per User). Just as a Data Analyst would do in real life.
Alternatively, in Mock Interviews the goal is to practice SQL syntax, so to solve an exercise one needs to submit a query.
Other than that there were no major changes. From the very beginning the idea was to build a course around a story of a company 
and you, as a student, will be a part of this story.
One of the easter eggs in the course: the characters are real – they’re inspired by my dear colleagues at Blinkist. 
Impact
“I would be interested to see how much money it makes (if you’re willing to share), how many users convert from the free to the paid tier.”
The last time I checked, around 1400 people created accounts on SQL Habit and started the course. A big portion of them purchased full access afterward.
I’m a bit shy to share numbers like “I’ve made $XXXXXX, booyah“ . I’d love to keep the purpose of this post to share the journey, explain how some critical decisions were made and what we can learn from it. 
Those users took 24K+ lessons and exercises, wrote 85K+ SQL queries. 
These numbers make me very proud and this is just the beginning.
“Give us some insights into what marketing channels worked best for SQL Habit.”
Honestly, for the past year SQL Habit grew organically.
Shortly after I shipped the first prototype I reached out to some Berlin startups and offered them to buy SQL Habit licenses. It worked perfectly and I’m super grateful that I went from 0 to hitting 4 digit revenue 
in a matter of weeks.
I also posted the project on ProductHunt and it was on the homepage for about 15 minutes before they took it down. Turned out, PH doesn’t feature Education products. What can I say?
I also shared SQL Habit on:
- Hacker News
- Indie Hackers
and I’m so grateful to have friends and colleagues who shared the course and helped me gain initial traction.
I haven’t done any paid marketing, so I can’t pinpoint a particular channel as the best. Hopefully, that list 
will become a part of your future project launch checklist. 
“How did you find your monetization model?”
I decided to charge people a fixed amount and give access to SQL Habit forever. As if you bought a book.
The goal of SQL Habit is to turn you into a Data practitioner in 1-2 months, give you the initial jump. Then you fly on your own.
Process 
“Is there something you would do differently in hindsight?”
Oh man, I’d do a lot of things differently. It probably deserves it’s own post, but here’s my number one:
Start now.
When I came up with the idea of SQL Habit I started programming. Immediately. I think an Engineer in me convinced the CEO, Marketer and PM that we should build a very advanced prototype first (oh dear). It took me 2 months and “the prototype” is basically the current SQL Habit without Mock Interviews. Crazy. 
Today I’d start building SQL Habit by writing a quick post on LinkedIn, asking 10-20 people to pay me $500 so I can teach them everything I know about data. In 2 months I’d have enough material to create a smaller version of SQL Habit, I’d have 10-20 happy students and some initial 
.
“Any valuable feedback you got from course participants?”
I don’t know where to start tbh: every feature in SQL Habit is inspired by someone’s feedback.
Positive feedback gives me the energy to continue building SQL Habit. When it comes to negative feedback, I appreciate every bit of it. Someone took time to critically analyze something in the course and shared that feedback. I’m extremely proud that all the feedback I received from SQL Habit students is always actionable and polite.
I organize my work in Trello and I have an IDEA label for everything students send me. If I see that some feedback theme is recurring it’s a signal to build this.
For example, when I launched SQL Habit you’d have to copy-paste queries from lessons into a separate tab with SQL Editor to run them. It was a quick solution to launch fast. After launch almost everyone said that they want to run queries in the same tab. Well, every page on SQL Habit has SQL Editor now.
“How do you balance your work at Blinkist, SQL Habit and personal interests?”
That’s a very great question which I’d answer differently if you ask it a year ago.
When I started working on SQL Habit I dedicated every single minute of my free time to it. I was building the website and was writing the course content:
- after work
- on S-Bahn (Berlin’s subway)
- in coffee places during weekends (oh, those pre-COVID times)
- on trains and plains
- on a ferry from Stockholm to Helsinki (worst trip ever, 12h of a non-stop roller coaster)
- right after my knee surgery
- you got the idea
That was really hard to balance because I have a full-time job as a Growth Lead Engineer at Blinkist. Working at Blinkist and SQL Habit complement each other. All Blinkist employees have access to SQL Habit and it’s a source of constant feedback and inspiration.
The problem was that I was working 2h every day after work for a month and then 0 hours after work for a month. It gives us 2 hours * 5 days * 4 weeks = 40h in 2 months.
Now I work on SQL Habit for 45 minutes but every single day. It gives us 45h in 2 months. That way I put in more hours in the long term + I don’t get mentally and physically exhausted. Instead, I’m present and enjoy every minute of these 45 minutes every day.
Burnout 
“I’d love to read about the moments (if any) you had wherein you wanted to give up on this project but persisted, and how did you fight back.”
When it comes to motivation, I think I’ve never lost it. I genuinely love everything related to SQL Habit (all right, I don’t really like dealing with legal and financial papers).
The critical part when I nearly lost it was the burnout 
. This autumn I got sick and something that seemed to be a regular cold turned into the 2 months long no-energy period. No energy to work, no energy to think, no energy even to watch Netflix.
Unfortunately, it’s not the first and not even the 2nd time something like this happens to me. A long period of extra high energy followed by a long period of near-zero energy. It’s not productive and unhealthy in the long run.
The recipe how I manage this is quite simple:
- Focusing on the project for 45 min a day (but every day) is way better than throwing 3 hour evenings that leave you with no energy
- Sport every day. 20-30 min workout will do the trick. Shake up!
- Hydrate. I simply bought a 2.2L canister and I carry it with me everywhere. It’s really funny that “everywhere” in the COVID times is kitchen, workroom and the bedroom
- Fruits, healthy food
- Sleep hygiene (sleeping mask, light alarm clock, Philips Hue to turn on the light with the alarm clock and blackout curtains)
- Being outside
It helps me to think that you start every day with a fully charged battery (bad sleep already makes this battery only 80% charged in the morning). By the end of the day, this battery has almost no charge (you’re ready to sleep and recharge) OR you abused it and it starts to break down. It’s simple math. 
Motivation
“I’d be curious to read about what keeps you motivated to keep consistently investing significant chunks of your time (in addition to a full-time day job) in this project. Surely it’s not just fame & riches?”
That’s a great question; I ask myself this question regularly to make sure I’m on the right track.
The short answer is: I simply love it. To build something that other people use and find useful; something that not just touches other lives, but changes them in a good way.
Here’s my favorite story: during the first Corona wave some companies in Berlin had to lay off their staff. I received a letter that a marketer who finished the SQL Habit course found a job as an analyst at eBay. That felt unreal and I continue to receive similar letters. Things like these are the answer to the question of why I should keep going.
Tech 
“From the technical view, it will be cool if you talk about how you create the platform (tech stack), in the evolution if you have changed or evolved that tech stack, how have been the answer to that cool feature: mock interviews, and how do you get ideas to that new features that are you getting on time to time.”
This is where comes the fact that I’ve been working as a Software Engineer for the past 10 years, I started programming when I was a kid. Well, my both parents are Software Engineers. 
SQL Habit is a Rails app, built up from scratch by me. I wanted the course to have a smooth experience of learning and advancing every day, bit by bit. And to have confetti at the end of each lesson. In my eyes, it justifies investing this time and energy to build a custom product.
I’ve already mentioned how Mock Interviews were born, maybe I can share how I work on smaller features. The trick is simple: user feedback. From the beginning I’ve added a feedback form on every page and my email account exploded.
For example, in the beginning a lot of students said that they can’t memorize the SQL syntax from the first go and have problems with exercises. That’s how the SQL Reference tab was born.
It’s hard to go through all the letters, but I know from experience that all the gems are hidden there. So far I’ve answered every single email and I’m not planning to stop there.
Outro 
I want to say thank you to everyone who supported me, all the students who took the course, everyone who left constructive feedback and shared their ideas. I’m so glad we’re making SQL Habit better every day.
I hope I was able to cover all the questions you had on your mind. If there’s anything else you’d like to know about SQL Habit’s journey – feel free to ping me on Twitter or leave a comment below. 
Merry Christmas 