Mykyta Tretynko, Billioncore — Stopping Fraudsters and Chargebacks
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Mykyta Tretynko is a 30-year-old software engineer in Kyiv and the solo founder of Billioncore, a service that helps small and mid-sized retailers spot fraud and chargebacks before a transaction goes through. He joined Mash over Zoom, late at night his time. They get into the $4 sticker order that turned into a $25 chargeback, finding customers on Threads, an introvert teaching himself to sell, and what it actually takes to build a startup from Ukraine — from missile strikes to payment processors that won’t take you.
This conversation has been edited and condensed.
“One of the first guys who was laid off”
Tell us a little about yourself, and about your startup.
My name is Mykyta. I’m 30 years old and I’m from Kyiv. I was born in Zaporizhzhia, in the southeastern part of Ukraine, and I studied there. I graduated from the university with a master’s degree in software engineering.
I started my way as a software engineer in the university. There was a department making IT solutions for the university, and I created a few projects there. I loved architecture — creating solutions that are helpful for people. Once I had the basic experience of architecture and building projects, I went to work for a private company, a local outsourcing company in Zaporizhzhia. There I got my first real experience on real projects: American projects, Australian projects, all over the world. A very different, amazing experience.
So you went straight from university to one private company, and then started your own startup?
I started when the first wave of software engineer layoffs began, because of the popularity of AI. The founder of the project I was working on decided not to use software engineers, and to use AI instead. I was one of the first guys who was laid off because of this.
That seems to be happening a lot. Is it a trend in Ukraine — using AI for software development and not hiring engineers the way they used to?
That trend was in the Australian project where I was working, a real estate project. The founder decided to use AI instead of software engineering. Sure, it’s his decision. But as a software engineer with the skills and the experience, I think AI shouldn’t replace the software engineer. It’s a dev tool. For a software engineer, it helps me deliver the result better and faster.
That will not change. Even the best model on the market gives very bad solutions if it’s not prompted very well, and if a software engineer isn’t supervising the results.
$4 in stickers, a $25 chargeback
Is that why you created Billioncore? First of all, what is the product?
Billioncore is a service created to protect small and middle retail businesses from fraud and chargebacks. I was looking at the market for opportunities, and I saw a trend — not a very good trend — in the United States, the United Kingdom and the European Union, where there’s a large problem with chargebacks and payment fraud. And I saw there was no solution that suits small and middle businesses. The existing products are either expensive, or they do the anti-fraud protection after the transaction has happened. So a merchant learns about the chargeback when it’s already happened. That’s not so good, for me.
I investigated Threads. It’s a place where you can see everything about the pains and problems of real founders. There I saw a list of real stories. One was about a Shopify shop founder selling $4 stickers. Somebody bought $4 of stickers, and that turned into a $25 chargeback. So instead of earning $4, the sticker cost the founder $25.
I thought that I need to destroy this, and help small and middle businesses protect themselves.
For people listening who don’t know what a chargeback is: it happens when somebody buys a product with a credit card, and then the cardholder complains to their bank — “Somebody stole my card, this isn’t my purchase.” The bank gives the money back to the customer, and then charges the e-commerce store the $25 you’re talking about.
Yes. They return the money and charge an extra fee. So a chargeback is much more expensive for the business.
The story of creating the Billioncore solution is interesting, too. Before this, I had a first version of the product written in PHP, but I saw its performance wasn’t so good. I wanted the best solution on the market. I’m a maximalist engineer: I want to make the best solution, technical elegance, the fastest. PHP didn’t give me this. That’s not a problem of PHP; it’s just not built for the fastest solutions. So I started to learn Go, Google’s language, and I built the core of Billioncore in Go.
I reduced the latency from 250 milliseconds to 5 milliseconds. So it’s the fastest solution on the market. Just five milliseconds: no conversion drop, no troubles, and the customer doesn’t even see that something happened on the back end.
A lot of Shopify owners aren’t developers or engineers. They don’t understand code. Is it hard for them to install?
The first solution is as simple as possible. They can just sign up for my service. If they aren’t developers, they can test it in the playground. It’s a special page where they can open their bad transactions, their bad orders, enter the BIN number and see what that BIN number is and what its performance was. And if a customer wants the solution, I have an API that’s very, very easy to integrate. It has very good documentation, with examples in any popular programming language. I think any software engineer can integrate this solution in one business day.
How big does a company need to be for this to be a reasonable expense? Some of these small shops might lose $25 or $100 a month.
The scale is when they start losing more than they’re earning — when they have cases like the sticker, where they earned four times less than they needed. That’s not very good news for a small shop. Small shops live on one item, three items. Every sale is important, and when the chargeback comes, it loses four such sales for the person.
How did you feel this pain? Were you the one selling stickers, getting chargebacks?
I’m not selling, but I monitor Threads, and I studied this. I talked with founders of e-commerce shops in the United States and the European Union, and I saw they have the problem with chargebacks. It’s a painful problem, and most painful for small shops, because they aren’t earning too much money and every chargeback is very painful for them. If they find a solution that helps them see the chargeback before it comes, it will save their money. I’m giving the instrument that saves the part of the money that can be saved.
A lot of founders have trouble with customer discovery. How did you find the customers to talk to? Did you just start calling Etsy stores or Shopify stores?
Just Threads. I started reading people’s posts. They’re the real founders — real Shopify founders, Magento founders — with the same pain, the same troubles. There are a lot of posts there: here was a chargeback, here was a chargeback. There was a case where somebody just tested a stolen card on the checkout. That’s also a pain. So I read about this pain, had some conversations with these founders, understood the pains, and made new versions that will stop this pain, or just reduce it.
“Before the transaction happens”
So you were able to build your MVP. Were the people you reached out to willing to pilot it? How many are using your product?
Now I have 10 retail businesses testing it, and I’m searching for more retail businesses that want to test it. The first month is totally free for them, because the first month is a study period for them and for me. The algorithm I’ve built is unique and new. Nobody used BIN numbers for this case before. My solution is based on BIN number performance.
Before this, BIN checkers just output data about the card and which bank it’s from — not very rich information. I saw that the number has more potential than just getting information about the bank. I found some other sources of data, connected these sources and built an analytics layer on top. Now I’m giving not only information about the bank, but information about the performance of the BIN.
It can be a good BIN, one that can be approved — go ahead with it. The second status of a BIN number is moderate, so the founder should look at this BIN number. And the third category is BINs with bad performance. This is the category where the chargeback is happening, so it’s better not to take this order — just decline it. It’s a pity sometimes. But it’s cheaper not to have this order than to get this order. My business is going to give this power and opportunity to founders.
How do the e-commerce store owners know your product is working? Do you give them data, a report? What do they get to see?
They see the output on their side, because my solution works before the transaction happens. That’s not like traditional anti-fraud engines, which work after it happens. So the founder has a chance to decline the transaction before it happens.
So you give them a signal — this is probably fraud — and they can decide not to accept it. Could you also give them a report at the end of the month: “We caught 32 transactions that were signaled as fraud”?
I give this power to the customer with the help of the API. I give all the needed information through the API, and a software engineer implements the logic the customer wishes. So I’m giving all the power to the customer. They receive a ready decision about this BIN, and then they can build any logic they want. They can automatically reduce the bad orders, just before they’re created, and they will see the result on their side, in fewer chargebacks. That’s the main result.
I don’t see the result, but I’m asking for feedback all the time — whether some BIN numbers really helped, whether something didn’t help — and I’m correcting my algorithm, adding data and improving. It’s self-improving. It’s symbiotic. Working with the founders helps improve my product, and improve their sales.
“The hardest part is marketing”
That’s a very common founder story — pilots, good customers giving feedback, adapting the product — and it sounds pretty well run. Congratulations. But what challenges are you facing? Have you raised money? Any trouble serving customers?
Before this, I thought that software engineering was a very hard thing, the hardest part of the product. But I was wrong. The hardest part is marketing and involving all the clients. As a founder, this is one of my biggest challenges, because I need to learn marketing and sales from zero. It’s a new field for me. I learned how to make cold emails. I learned how to do the social media job on Threads — I’m the only social media manager on my Threads. That’s the first challenge for me.
And the additional challenge is that I’m an introverted person. I’m a closed person. To become a founder, I need to talk more, be more open, speak with people more and more. That’s my inside challenge.
“I was wrong. The hardest part is marketing and involving all the clients.”
— Mykyta Tretynko · Inspiring Founders Podcast, Ep. 10
Tell me how you overcome that anxiety. A lot of founders are so scared of talking to people that they’d rather send an email or a survey than get on the phone — or do what you’re doing with me right now, and talk face to face.
That’s very hard for me, every time. But the recipe for conquering this thing, I think, is that when you’re facing your fears, you need to face them and conquer them. When you come out of your comfort zone — that’s the only recipe, when you conquer your fears.
When you walk through that fear and do it, is there a feeling at the end — “Yes, I did it”?
Yes, I did it. Every time, after one more email, one more conversation with some managers, some founders. As I said, I’m an introverted person, so every email is very important for me, very personal for me. I’m conquering myself. My future goal is to become a more open, more extroverted person, because a founder should be. At home I can be introverted, but as a founder I should communicate.
If Billioncore gets big, you’re going to have to fly all over the world, go to conferences where people talk about fraud, maybe give speeches. Are you a solo founder?
I am a solo founder now. I’m looking for salespersons, I’m looking for marketing persons. I understand that I’m a deep technical person. I should know how to sell, I should know how to market, but some people are best in marketing, some people are best in sales. So I’m looking for such people. I don’t have any fundraising. I don’t have any partners now. So I’m beginning from zero — and I think this is the most interesting part of a startup, from zero. Trying to grow from the seed.
What makes that possible today? You couldn’t just say, “I’m going to start a cybersecurity company that prevents fraud and chargebacks,” and do it all by yourself. Are you using AI?
For the coding, I’m using Claude Code to improve my speed. That’s the basic thing.
I have a full-time job now, and a second full-time job as a founder of my own company. After the working day, I’m doing tasks, features and bug fixes as a software engineer. I’m the only software engineer in my company, so I should do this stuff. And then I go to marketing. I spend about four hours per day on marketing: collecting leads, sending emails, going to Threads, where I found you. That’s the second job, and the most important for me.
In the beginning, a founder probably needs to get the first 100 clients at least, and you’re doing exactly that. It’s going to take a lot of your time. There are a lot of tools out there that can help, and I’ll put in a plug for Radi8, a company I built myself to help founders do more social media marketing. If you want to try it, I’d be happy to set you up with an account, and see if it saves you some of those four hours, because that’s a lot of time. But being a solo founder with access to AI and Claude Code, you can probably do by yourself what used to take an entire engineering team, right?
For me, I think at the start, me as the software engineer will be more than enough, because the back end of the project isn’t so big now. I can do it on my own. When it grows, yes, I will hire some software engineers. I will need a technical support team. I will need a sales team. I will need to grow.
How do you know when it’s time?
When I’m not able to deal with the amount of tasks and the amount of technical support. That’s the point when I should hire a person, and hire immediately. And ideally, I should hire them before I start facing these problems.
That’s a big challenge for founders: knowing whether you need to raise money to make those hires, or stay self-funded and make enough from customers to hire people. Are you going to stay small and grow slowly, or try to raise at some point?
I want to raise money, if it will be possible. It’s a very good way to grow higher and faster, because when you’re bootstrapping, you don’t have a high budget. You’re growing slowly, slowly, slowly. Maybe that’s cool for a small company, but my ambitions are not small now. I think the bad businessman is one who wants to stay in the garage. Amazon, Apple — they would never have grown up if Steve Jobs or Jeff Bezos wanted just to stay in the garage. In the future, I want Billioncore to be a standard in payments.
Building from Ukraine
Let’s talk about Ukraine. How is the war affecting you, the economy, the startup scene, your ability to have a startup? And what’s the investment ecosystem like — are there VCs, is money being invested in startups?
In Ukraine there are a large number of startups. There’s an ecosystem, yes. But the startups are fundraising on actual Ukrainian problems, and the problem of chargebacks and fraud isn’t so hard here in Ukraine. I’m working on the problem, and the business, for the markets where it exists. So I won’t be able to fundraise here in Ukraine, because people won’t invest in something Ukraine doesn’t need.
The war affects all Ukrainians, every day. It affects the economy; the economy is struggling because of the war. And any day there can be a missile strike on Kyiv, like there was two days ago. It was a hard missile strike here.
But it’s not as terrible as people think. Some customers I talked with before, when I was a software engineer, thought we were always somewhere underground, hiding, because there are bombs here every day, every night. It’s not so. But it’s hard to bootstrap here, because of the danger, and the electricity problems.
Another problem I face is that some payment services don’t work in Ukraine. For example, Stripe doesn’t work in Ukraine. Another service does work in Ukraine, but they saw that I’m from Ukraine and declined me when I tried to open subscriptions. So for now, for the first step, I have to use crypto as the payment on my website, because it’s the only way I can get money at the first step.
My future plan is to earn the first money, then open the company somewhere that’s a free economic zone — something like Hong Kong, the UK, America. I know there are such opportunities for foreign startups — and then get the payments in the normal way.
It’s hard enough being a startup founder in Silicon Valley, right in the middle of all the VCs. It must be enormously difficult in Ukraine, dealing not only with the war but with customers who aren’t in Ukraine — I imagine a lot of late nights talking with customers in the US. Are you seeing this problem anywhere else that’s as big as the United States — Australia, Europe?
Yes, I’m trying to talk not only with United States customers. I’m talking with United Kingdom customers — I sent tons of cold emails to UK retailers — and I’m trying to find customers in the Netherlands and Germany, where such problems are hard and exist too. But I can say it’s very hard in the beginning, because when you’re not famous, not a famous startup, people are just closing your email.
But I’m trying to deal with this. I believe in myself. I believe in the product. I know that this product is useful. This product is needed. That’s the main thing. And it’s like a mission for me: to help small businesses survive, because every chargeback is harmful for them. I want to give them a chance to survive, to feed their families, to earn the money that is very, very important for them.
“The bridge between the people”
You and I met on Threads — the social network from Meta. I like Threads a lot because you can have more personal conversations. Are you on any other social media, like Instagram or LinkedIn?
I have LinkedIn, I have Instagram, but I think Threads is a very underrated social network if you want to face somebody face to face. It makes you closer to the founders. If you’re just writing a message on LinkedIn, it’s just another message for the founder. It can be just noise. On LinkedIn, maybe they have tons of messages — some HR, some people who are just messaging them — so this will be just more noise. When you’re facing them on Threads, you’re facing them personally. It’s the bridge between the people, people from anywhere. It’s the most underrated place where you can meet your ICP. I recommend this.
More conversations with founders on the Inspiring Founders Podcast.