Andrii and Dmitro – blockchain bros born a year to the day apart

When I spoke to the two brothers, both relatively recent additions to K&C’s team, it turned out their backstory was even more interesting than I’d hoped

Blockchain & Web3 developmentUPDATED ON August 15, 2023

John Adam K&C head of marketing


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On October 7, 1985, a baby boy was born in Kharkiv in eastern Ukraine. His parents named him Dimitry (Dmitro to his family and friends). Exactly one year later, on October 7 1986, his little brother Andrii was born.

Sharing a birthday just a year apart proved to be a strong omen and Dmitro and Andrii grew up incredibly closely. Dmitro even waited a year for his younger brother and the pair started school together, in the same class.

He is keen to tell me his little brother is his best friend and one of the greatest people he has ever met. And that he’s thankful to his parents for gifting him as a first birthday present.


These 2 brothers are like magnets – their energy keeps pulling them back together

Central Kharkiv before Russia invaded in early 2022

Central Kharkiv before Russia invaded in early 2022. Dmitro and Andrii grew up in one of the city’s suburbs


Dmitro and Andrii went through the entirety of their school years as classmates as well as brothers. When not in class, they played with cousins and friends living in and around the same block in one of the Kharkiv suburbs. The neighbourhood was, and is, like so many across the former USSR and wider Eastern bloc, dominated by decaying prefabricated blocks of flats that mostly went up in the 60s and 70s.

Many of the facades look like haven’t seen a lick of paint since. But they are mostly still standing, and still home to millions of families. Others have been destroyed by the Russian shelling and missile strikes that Kharkiv has suffered since February 2022. The pounding was particularly brutal over the first two months of Russia’s ongoing invasion of Ukraine when the city was on the front line.

The brothers moved to a new apartment in their early teens. But they were still in the same neighbourhood and continued to run with the same group they always had. They were obsessed with computer games by this point, and lucky enough to be among the first to have their own at home.

That meant the Yermenkovs’ home quickly become a magnet for friends keen to get in on the action. First on games held on cassettes loaded by a Robik – a Ukrainian-made Spectrum clone. A few years later and the boys and their gang had graduated to enjoying Desert Strike on the Sega Master System.

Eventually, when the brothers finished school together, they won places and enrolled at university together. The same university of course – The Ivan Kozhedub National Air Force University. And the same course – Computer Science taught by the civilian faculty.

Dmitro (left) Andrii (right) as university students in Kharkiv. May 16, 2007

Dmitro (left) and Andrii (right) at university in Kharkiv. May 16, 2007


When they graduated, they started work as software developers together. In the same company.

Dmitro and Andrii don’t live in Kharkiv anymore. With the itchier feet of the two, Andrii moved first from Kharkiv to Kyiv, Ukraine’s capital. Though Dmitro remained in Kharkiv, the brothers were soon working together again. He was employed remotely by the same company Andrei was working for in Kyiv.

Andrii’s urge to explore took him to Asia next, where he spent 8 months as a digital nomad. His stay was unexpectedly extended by several months, 3 of them on a small island, when the Covid pandemic struck. But he did have his girlfriend, now wife, with him for company.

When borders reopened and flights started to take off again, Andrii’s next move was to Poland. He still lives there in Warsaw. And as you might have guessed, Dmitro also ended up in Poland and lives near Krakow with his wife, son and daughter.


Play together – work together

And Dmitro and Andrii are working together in the same company again. In the same team, on the same project.

They are now blockchain developers, having both become interested in first cryptocurrencies and then the underlying digital ledger technology that enables them. First through personal projects and then work experience, they added Web3 architecture and Solidity, the programming language native to the Ethereum smart contract blockchain, to already impressive web development skills.

That’s how we met. Andrii joined K&C in March of this year as the first member of a new team that is now four strong. They are building the SDK (Software Development Kit) and Dapp (Decentralised Application) of one of our clients, the U.S.-based DeFi startup Ajna.

Ajna is building a non-custodial, peer-to-peer, permissionless lending, borrowing and trading system that requires no governance or external price feeds to function.

Dmitro became the new team’s third member, reuniting with his brother professionally for the third time.

I got to know Andrii first when I spoke to him a few weeks ago. He was helping me put together a case study on the Ajna project. When, as he explained the team’s growth and the project to me, Andrii mentioned his brother had joined the team, I was intrigued.

It sounded like a good story. And I’d just confirmed a series of profiles on K&Cers. What better way to help current and potential clients get a better feel for who we are as a company than some insight into the team?

So I got back in touch with Andrii, told him that, and asked if it sounded like something he and Dmitro would be up for. They were. And here we are.

It turned out to be an even better story than I had hoped.


Journey to the centre of the blockchain

As you might expect, Andrii and Dmitro look alike. I get the impression they’d look even more alike if either Dmitro grew some stubble or Andrii shaved his off.

Andrii usually talks first and more. Dmitro doesn’t mind. He smiles while listening, occasionally interjecting to add any detail that’s been missed or he thinks should be expanded on.

So how did they both end up as blockchain developers working on the same project? There was, says Andrii, never any doubt that they would be coders. That destiny was etched in stone over those childhood years playing computer games and then starting to experiment with coding.

They both wrote their first lines of code in BASIC on that Robik in the mid-90s. While other kids might have struggled with the vastness of the variety of potential paths open to them as they approached adulthood, Dmitro and Andrii avoided that angst.

They knew for years before the time came which course they would study and at what university. Their grandfather, one of those men blessed with an unerring competence at seemingly anything and everything he turned his hand and mind to was an alumnus.

And not just any alumnus – a stand-out student featured on The Ivan Kozhedub’s wall of honour. The boys’ father was also a natural talent at anything technical. And not only – he would spend hours drawing with them when they were young, amazing them with his own sketches and showing them techniques. He instilled in them drive, curiosity and a hunger to learn – and master.

Building of the Kharkiv Air Force University named after Ivan Kozhedub. Facade of an old building with a signboard among yellow autumn trees on a sunny day

Building of the Ivan Kozhedub Kharkiv Air Force University where Dmitro and Andrii graduated in Computer Science, following in their grandfather’s footsteps – a roll of honour student at the university two generations earlier


There was never any doubt the pair would become the next generation of gifted engineers. It just wasn’t a question.

After several years of advancing their careers as web developers after graduation, first in Kharkiv, then Kyiv, the buzz around cryptocurrencies and blockchain caught the interest of both brothers. Dmitro started dabbling in cryptocurrencies first, then Andrii.

At first they were, like many others, amateur traders caught up in the excitement of the booming new corner of the digital world. But then the curiosity that took them under the hood of the computer games they enjoyed so much as kids took over again.

This time they lifted the hood of their new hobby and started learning how the blockchain technology that cryptocurrencies are built on works. Their first foray was into cryptocurrency mining – the contribution of computing power to the solving of cryptographic problems that verify crypto transactions.

Encouraged by friends who had already done so, Andrii and Dmitro bought a bunch of graphics cards and bare metal frames and set up a small Ethereum mining operation. Each time the work of their whirring, blinking DIY mine led to an ether being dropped into their crypto wallet, they’d cash it in and use the proceeds to buy more hardware.

But with crypto mining growing in popularity in Kharkiv, they started to find it hard to buy up more graphics cards. All the local sellers were out of stock.

Andrii managed to find a wholesaler in western Ukraine and a road trip quickly followed. About $15,000 was exchanged for a car full of graphics cards and other bits of hardware. Next was a long journey back to Kharkiv where an unused family property on the outskirts of the city became host to the growing mining rig.

Image of a crypto mining rig similar to those in farms like the one Andrii and Dmytro set up

Crypto mining rigs apply their computing power to solving the cryptographic problems that blockchain transactions and security rely on. Miners are rewarded for their valuable contribution to the P2P network in newly-minted cryptocurrency. 


Around the same time, both brothers were starting to get to grips with blockchain development and Web3 architectures and technologies through personal projects. They eventually moved into paid roles in the space, building experience in the nascent software niche.

Andrii also left on his Asian adventure before returning to Europe with a blockchain position that saw him start life in a new city – this time Poland’s Krakow. Dmitro moved to Warsaw with his job.

Then Russia invaded Ukraine.


A socialist era block in Kharkiv, Ukraine, partly destroyed by a Russian attack

A socialist era block in Kharkiv, Ukraine, partly destroyed by a Russian attack. 


Kharkiv, Ukraine’s second largest city with a pre-war population of almost 1.5 million, is majority Russian-speaking and just 30 kilometres from the border. Capturing it was a key strategic target of Russia’s early onslaught and paratroopers and armoured divisions pushed deep into the Kharkiv Oblast and parts of the city in the first days and weeks of the invasion.

They failed. By May, Russian units had been pushed out of the city and back towards to border. By September, the invaders had been completely driven from the wider Oblast.

Kharkiv has paid a heavy price with tis unexpected resistance and proximity to Russia placing it high up the list of targets for shelling, bombing and missile strikes.

Andrii and Dmitro made a trip back to Kharkiv last year after the Russians had been driven out. The property the brothers had used to host their crypto-mining farm is in a region briefly occupied by the invaders. It had been gutted and every last graphics card and rack stolen.


Poland – for now

Dmitro (left) Andrii (right) with Dmitro son in Poland. Sept 30 2022

Dmitro (left) and Andrii (right), with Dmitro’s son in Poland. Sept. 30, 2022.


The brothers are sanguine about the loss. The rigs had been offline for some time anyway and they hadn’t expected to find their pet project in a recoverable condition.

And anyway, they are now deeply immersed in another dimension of cryptocurrencies and blockchain – developing the Dapps, software and protocols that will one day soon, they are convinced, blossom in the spring that follows the current crypto winter.

The blockchain economy that emerges from the debris left behind by the bursting of the crypto assets bubble that had blew up and then burst in 2021 should be far more sustainable than what went before. Many expect a similar pattern to unfold to the one that shaped the aftermath of the bursting of the dotcom bubble in 2000.

Most of today’s tech giants rose to prominence in that period, refining online business models and benefiting from a general maturing of the online environment.

In today’s blockchain space, DeFi infrastructure to rival that of mainstream financial markets and institutions is being invested in and built quietly in the background.

And Dmitro and Andrii Yermakov, two brothers from Kharkiv – the grandsons and sons of previous generations of talented engineers from the same city – are making their contribution to the huge building job ahead. I expect they’ll continue to do a lot of that work side by side, as they’ve been for most of their lives.

And if they do ever split again for a period, I’m pretty sure the force that’s kept these two brothers so tightly bound to each other since October 7 1986 will drag them back into each other’s orbit again soon enough.


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