As an engineering student at the University of Moratuwa, “free time” was a concept I had only heard rumors about. Between labs, exams, and extracurriculars, I didn’t have time for a traditional part-time job. But I needed money to buy a laptop, pay boarding fees and for food, pocket money etc.
But like everyone else in Sri Lanka, I knew the value of earning in dollars.
I always wanted to publish my own book. The problem? Writing a 300-page novel takes months of intense creative energy I didn’t have. I needed a smarter way to enter the Amazon marketplace. I needed an engineering approach to publishing.
So, I ran an experiment. I decided to try Kindle Direct Publishing (KDP), but instead of writing words, I used logic. I started publishing Sudoku Puzzle Books.
Here is how a mechanical engineering student managed to create a passive income stream on Amazon, and how I got that money back to Sri Lanka.
The Strategy: “Low Content” Books
While researching KDP, I discovered a golden niche called “Low Content” or “No Content” books.
These are books where the user provides the content—think journals, planners, logbooks, and puzzle books. They don’t require months of writing. They require good design and smart niche selection.
Why Sudoku? As an engineer, I love logic. Sudoku is analytical, repeatable, and hugely popular globally. It was the perfect product to test the Amazon algorithm without risking hundreds of hours writing a story that might not sell.
The Process: Treating It Like an R&D Project
I didn’t just throw a book together. I approached it like a university project.
- Market Research: I looked at the best-selling Sudoku books on Amazon. What were their covers like? What was the difficulty level? I realized there was a demand for specific niches (e.g., “Hard Sudoku for Seniors” or “Large Print Puzzles”).
- The “Manufacturing”: I didn’t draw thousands of puzzles by hand. I used puzzle-generation software to create the interiors efficiently. My main effort went into designing an attractive, professional cover using tools like Canva.
- The Launch: I used relevant keywords in the title and description so people searching for puzzles could find my book.
(You can check out one of my successful experiments (Don’t think about my name. I used a pen name) here: Amazon – Killer Sudoku by Alex Simpson)
The Result: Earning While Sleeping
The magic of KDP is that it is truly passive. Once I uploaded the PDF file, Amazon handled everything—printing, shipping, and customer service.
I still remember the first time I checked my KDP dashboard and saw a royalty spike. I was sitting in my room in Sri Lanka, probably studying for a thermodynamics exam, and someone in the United States had just bought my book.
It wasn’t millions overnight. But it was real dollars, earned entirely online, from a product I created once and never had to touch again. Here how it’s still performing. I am not uploading any books now but I am getting real money yet.
The Sri Lankan Challenge: How to Get Paid (Payoneer)
For Sri Lankans, making money online has always had one major hurdle: getting it out.
Amazon KDP does not do direct bank transfers to Sri Lankan rupee accounts. If you ask for a check, it takes months to arrive and clear.
The solution is Payoneer.
Payoneer gave me a virtual US bank account number. I connected this to my Amazon KDP account. Amazon deposits the dollars into Payoneer, and from there, I can easily withdraw it directly to my local Commercial Bank account in LKR. It works seamlessly.
Final Thoughts
My KDP journey proved something important to me: you don’t need to be a brilliant novelist to be a publisher. You just need to identify a market need and find an efficient way to fill it.
My Sudoku books are still up there, selling occasionally. It’s the perfect side hustle for a busy student or professional. If you are willing to experiment, the opportunity is there.
Want to know about how I almost failed my first semester while making money?
Sasindu J. Mallawa Arachchi Mechanical Engineer (B.Sc. Hons, University of Moratuwa) | R&D Engineer
Sasindu is a Mechanical Engineer specializing in Energy Conservation and Thermal Systems. Currently working in R&D at Alta Vision Pvt Ltd, he writes about the gap between engineering theory and real-world application. In his free time, he writes fiction and shares his personal experiences to help others navigating similar paths.