The Stack Overflow Podcast

Hashgraph: The sustainable alternative to blockchain

Episode Summary

On this sponsored episode of the podcast, Ben and Ryan chat with Matt Woodward, head of developer relations at Swirlds Labs. Swirlds Labs created the Hedera ecosystem, a DLT built on a hashgraph, not a blockchain. We chat about what the difference is between a blockchain and a hashgraph, Hedera’s focus on environmental sustainability, and why the Web3 version of “Hello, World!” takes a little more effort.

Episode Notes

When most people talk about Web3 or cryptocurrencies and related technologies, they usually mean blockchains. But blockchain is only the first generation of distributed ledger technology (DLT). As with any new technology, once people see how it works, new generations come along rapidly to address the faults in the previous ones. 

On this sponsored episode of the podcast, Ben and Ryan chat with Matt Woodward, head of developer relations at Swirlds Labs. Swirlds Labs created the Hedera ecosystem, a DLT built on a hashgraph, not a blockchain. We chat about what the difference is between a blockchain and a hashgraph, Hedera’s focus on environmental sustainability, and why the Web3 version of “Hello, World!” takes a little more effort. 

Show notes

Hedera’s hashgraph is a third-generation DLT: it’s an open-source consensus algorithm and a data structure that uses a direct acyclic graph and two novel inventions, the gossip about gossip protocol and virtual voting. 

Where Bitcoin can only handle between three and seven transactions per second, a hashgraph can support upwards of 10,000. 

There’s been a lot of talk about the environmental impact of cryptocurrencies. Woodward says that a single Bitcoin transaction uses 1000kW-hours—the equivalent of driving a Tesla Model S 5,500 km—while Hedera uses 160 MW-hours of energy per year, about 2.5 million times less.

Congrats to the winner of a Stellar Question badge, g.revolution, for their question What is an anti-pattern? 100 users saved it for later. 

Find out more about Hedera and hit the start button

Connect with Matt, Ben, or Ryan on Twitter.

Episode Transcription

[intro music plays]

Ben Popper Hello, everybody. Welcome back to the Stack Overflow Podcast, a place to talk all things software and technology. I am Ben Popper, Director of Content here at Stack Overflow, joined as I often am by my colleague and collaborator, Ryan Thor Donovan. Hey, Ryan.

Ryan Donovan Hello, Ben. Do you have a middle name I can shout out?

BP Migdal is a Hebrew word, I think it means tower. It might have some significance somewhere, but it doesn't have any movies attached to it that I'm aware of. No Marvel franchise. 

RD Not yet, not yet. 

BP So you and I have been on many episodes talking about crypto, Web3, blockchain. You often shake your fist, angry old man at the cloud about it. But today we're talking about a hashgraph, which is not a blockchain. So don't bring any preconceptions to this, okay? 

RD Too late. 

BP Our guest today is Matt Woodward. He is Head of Developer Relations at Swirlds Labs, which is working on getting folks interested in this technology and adoption of Hedera. Matt, welcome to the show. 

Matt Woodward Thank you very much for having me, guys. Pleasure to be here. 

BP So let's start out, Matt. Just give a little background. How'd you get into this world of software and technology and what landed you in the role you're at now? 

MW Yeah, for sure. I should probably start with a bit of a confession that I've been a full stack developer for 20 years. I kind of feel like that's a preface that I probably should throw out there. 

BP Yeah, you’ve visited Stack Overflow once or twice, maybe. 

MW Yeah, something like that. I suppose early career I kind of was in that space, as we all do, of learning how to build new sort of end-to-end systems, and I’m thankful and lucky enough to have some great mentors at that time in my career. And I shifted from there into learning how to do integration with enterprise systems, so kind of stepping up into that sort of big world of having systems talk to one another. And then for the last 10 years of my career I kind of stepped more into an owner/operator kind of space, so kind of really looking at things with the lens of innovation and startups and running companies in that sort of way. So that was really interesting though more of a business lens. But I guess really over the last two years was when I really got into Web3 and sort of the crypto world, if you like. So that's where I guess in that part of my journey, I was sort of initially learning about those ecosystems, trying to figure out how to use them, how they were created, how they were made, all those types of things that kind of intrigue you as a technology person that you're passionate about. And it was in that space that I found Hedera. I was super impressed with their technology early on and that pulled me in to want to go a bit deeper and I really liked their focus on sustainability and ethics as well. So I guess I kind of gradually got pulled into that and I did things like creating my own NFT project and that's where I started to get my hands dirty a little bit in the DLT space, trying to go, “Okay, well how do I use this tech?” And I think then through being in that community, I got dragged deeper into wanting to explore the tech more, and that hand in hand goes for some of the circumstances that you see early on in the space, so people losing access to their wallets and things like that. And so I would do some scripting to try and help people with that type of thing. I would build my own repo scripts and do some YouTube videos to help others to learn about the technology, and then working with some NFT projects like Hederian Dragons to integrate Hedera with gaming projects as well like tabletop simulators. So I got kind of pulled into that space quite early on into that sort of journey. And then shortly afterwards I joined my current role as Head of Developer Relations at Hedera to really help embrace the kind of growth of developers looking at this technology. So that's probably my story in a nutshell. 

BP Very cool. Well, good. Yeah, I know some people have jumped headfirst into the crypto Web3 ecosystem. I'm sure our listeners, many of whom are veteran developers, will appreciate that you did full stack before it and then got drawn into this.

RD Ben said at the beginning of the show that we've talked to a bunch of crypto folks and they're all using blockchain, and I found out you all use a hashgraph. What's a hashgraph and what's the difference? 

MW Great question, and one that comes up a lot, I think. Well to start with, if we look at it from the point of view that blockchain is a first-generation Distributed Ledger Technology or DLT. And that really gave us decentralized trust, it gave us programmable money as well. As a platform, it uses a consensus mechanism called proof of work, and as such has quite high energy and computational requirements to run that. On top of that, you have inefficiencies with that kind of technology as well, because it is in essence a chain of blocks and you constantly have to prune off any other blocks that are trying to sort of come out the side so you maintain the integrity of that single chain. And I guess as a security measure as well, it was designed to be slow as part of that. All of those factors mean that that technology is inherently quite difficult to scale. Then you have a hashgraph, which on Hedera is a third generation DLT, you would generally hope is going to be doing things a lot better. So you're right, fundamentally a hashgraph is not a blockchain. The hashgraph is an open source consensus algorithm and a data structure. So it uses a Direct Acyclic Graph or a DAG, and two novel inventions. One is the gossip about gossip protocol, and that's what enables the nodes to very quickly synchronize their copies of the ledger. The other one is virtual voting, and that enables nodes to independently and consistently order transactions and arrive at that same result without the need to necessarily talk to each other and congest a network with votes or receipts. So that capability is what enables hashgraph to support upwards of 10,000 transactions a second and arrive at finality of consensus in three to five seconds. So in essence they’re two ways of solving the same problem, if you like, but one is obviously more efficient than the other. So hopefully that clarifies that a little bit for you.

RD Sure. Yeah, I'd heard that blockchains could only do three or four transactions a second so that is interesting that it’s built for speed. 

MW Correct. Yeah, absolutely. 

BP And then Matt, one of the things you mentioned at the beginning thinking about moving from a more traditional full stack developer into the new world of Web3 and crypto was that you appreciated that Hedera had thought about the environmental impact from the beginning. So what is the environmental impact and how does it compare to more traditional blockchains? And I guess we should probably say that some of the more traditional ones like Ethereum have changed recently in an effort to become more environmentally friendly. So certainly something a lot of folks are thinking about.

MW Correct, yeah. And I think this is one of those topics where as an industry there's been quite a lot of reputational damage because of the amount of energy that is used by some of the early technologies. And in essence, that same dynamic plays out time and time again in a lot of different industries. When there's something brand new, it's never going to be as efficient as it could be. And the idea is that the evolution of it is always going to improve on that. As developers, we kind of know how quickly technology evolves, and obviously the later DLTs like hashgraph and Hedera have come a long way. So to try and contextualize it a little bit and put some framing around the energy and the sustainability angle of it, if we do a quick comparison, you could look at Bitcoin and on average the platform underneath that expends around 200 terawatt-hours of energy per year and emits around a hundred megatons of carbon per year. On top of that, it's generating around 32,000 tons of electrical waste from obsolete hardware annually as well. So there's a lot in there when you look at that and it's no wonder there's a lot of people, and when you start scratching beyond the surface it gets scary quite quick. And that translates to a couple of really important figures. One is that, essentially for the average transaction on blockchain for Bitcoin, it's a thousand kilowatt-hours per transaction. So I want to contextualize that for you. 

BP Yeah. I have a solar panel system at home and a plug-in car so I happen to know that that's an absurd amount for a single transaction.

MW It is. If you had a Tesla Model S, that would be the equivalent of you being able to drive around 5,500 kilometers. So that's a massive amount of energy. And the next one's really going to pale in comparison to this sort of thing, but from a Hedera point of view, our networking expends around 160 megawatt-hours of energy a year, which is about 2.5 million times less. I'll just say that again– 2.5 million times less. But that's the beauty of it being a third generation. It's had that evolution, it’s had that improvement. And we emit around 80 tons of carbon per year, and that's actively being offset to ensure that we're carbon negative as well. So we're looking at it through the lens of making sure that any activity we're taking is being offset and handled appropriately. 

BP Say again how much it is per sort of iteration of the block. Was it 10,000? Is that what you said?

MW In terms of the energy expenditure, sorry? 

BP Yeah.

MW So for Hedera it's 160 megawatt-hours per year, which is 2.5 million times less. 

BP No, no, the first one. You had it Tesla charges, but what was it? 

MW Yeah, absolutely. So let's go onto that. So in terms of the actual energy transaction on Hedera, the average transaction is –ready for this? There's a lot of zeros here– .00017 kilowatt-hours per transaction.

BP Right, and what were the kilowatt-hours for the Bitcoin, again? It was wild. 

MW A thousand kilowatt-hours, and that's pretty conservative as well in fairness. 

BP Yeah, I had looked this up. What this reminded me of was that I had done a bunch of research because I got a home with solar panels. A thousand kilowatt-hours– that's even a little bit more than what the average home consumes in one month. That's like a whole month worth of electricity for a house. 

RD Wow. 

MW It is. It's huge, absolutely huge. And look, the Hedera lens on it is –again, I did the comparison on this– it's 5.8 million times less. So let's go back to our Tesla for a second. You've just driven 5,500 kilometers doing your Bitcoin transaction. On Hedera, if you were doing that you would drive 94 centimeters. It's a considerable difference, right?

BP Yeah.

RD So this is Web3 and all, but a very new generation of Web3. How does somebody get started in programming on the hashgraph? 

MW So in contrast to traditional ‘Hello, world’ examples that you might use to become familiar with a new language or technology, you need to understand a few more concepts to let you engage with the network when you move into Web3. So there is a little bit more to it in that sense, which is where I think it jars a little bit for developers coming over into the space. So think about it that you are going to need to grab an account on a network that you work with, and you could use that for both things like storing tokenized assets such as currencies, or you might be somebody that's into NFTs for art or music or utility-based functionality around that too. But you'll use that account to sign transactions that you submit to the network. So immediately you are needing to familiarize yourself with the authentication to begin your development journey, and that's a little bit of a leap that if you imagine putting that at the forefront of your journey, it's enough.

RD It’s a bigger ‘Hello, world’.

MW It is! Quite right. And so you've got that to start with. I think then as you move beyond that initial sort of leap into it, you've then got a look at the network itself that you're working on and what that network offers. In the case of Hedera we have a consensus service, and that lets you create verifiable timestamps and event ordering, and you use that in both Web2 and Web3 applications for that matter. And we've got a token service, so that would let you sort of configure and manage native fungible and non-fungible tokens. And we've also got a smart contract service as well, so that's where you can build decentralized applications and protocols using Solidity on our EVM compatible service. So you then look at that range of offerings there and kind of go, “Okay, well this is what I can actually use as far as functionality is concerned on this network and I can utilize that in my application.” So immediately then, compared to where you were with perhaps traditional software development and thinking, “Okay, I've got to build all this different functionality out for the projects I'm working on,” you've actually got access to a whole range of services, and in essence, a whole range of new use cases that just simply weren’t possible before with all of those being available to you. And that might be things like microtransactions or decentralized ID or asset tokenization. Things like like I said about the verifiable timestamps, you can kind of use that for anything that's around compliance or regulation. You basically have this whole new world of capability that opens up to you as a developer, so it's a pretty exciting journey to go on for sure. 

BP Yeah. So Matt, I'm curious, how long have you been with the organization for? 

MW Sure, so I'm still a baby in the grand scheme of things, but I’m just coming up to about three months for me. 

BP Three months. So as you look out at folks who are working with Hedera in some way, or folks you've met in developer relations, what are the things you see happening now that you think are interesting? You just mentioned some use cases, but have you interacted with specific developers, projects, or organizations where you say, “This is either fully Web3,” or, “This is more traditional development meeting some of the interesting elements of Web3 and doing it with our technology.” 

MW Yeah. So look, where I think is really interesting in this space at the moment is that, as a developer coming into this space, it would be really easy to think –there's a phrase around this I'm going to use– that you kind of could throw the baby out with the bathwater, and it's not that kind of sentiment. You can come into Web3 and still have a hybrid approach of still being able to leverage some of the things that you've used in a Web2 world and start integrating with Web3 components within it. So you don't have to leap holistically into a pure Web3 kind of mindset, if you like. So I'm seeing some really interesting work going on in that sort of area too as people move across into this space. But generally the one that I really like at the moment that talks to me is in essence a whole CBDC kind of space where you're looking at the finance world and how they're trying to integrate with the Web3 kind of shift that's come along. So I'm really interested in that. I'm seeing companies like EMTECH, for example, building regulatory sandboxes that enable both institutions, regulators, and providers to all come together in one space and kind of go, “Hey, we're entering a new era here as far as technology is concerned and ways of operating. What does that look like for us? How can we put together policies, processes, and ways of working in combination with the technology to get the outcome that we need to make this an effective end solution and way of working for people out there in the community?” And so I'm really enjoying seeing that type of development come about, and I'm enjoying seeing companies being open and curious about what this new kind of way of working can look like for them. So that's definitely something that's piqued my interest as I've been in this space. 

BP Cool.

RD So I know all the Web3 guys are always looking towards the future, so what's next? 

BP Yeah, look into your crystal ball, Matt. Now that you've drank the Kool-Aid.

MW I literally have my crystal ball right in front of me right now. 

BP Now that we've made computers speak in economic primitives and we've connected everything, what's going to happen?

MW Okay, so I suppose in terms of what's next if I think about Hedera specifically, what I'm excited about right now is the rollout of our native staking. That's going to help us facilitate a deployment of permission to community nodes for decentralizing the network even further, and I think the community has really been hanging out for that. So I'm really looking forward to where that's going. If I'm looking at it from an economy point of view, I'm just seeing whole rafts of new economies evolving as we speak. You look at things like play to earn, learn to earn, create to earn, there's a whole different level of projects that are coming out around that. The new gaming paradigms for example, using asset tokenization that are going to allow players to use resources that they may have earned or won across different gaming experiences. Or in some cases they might even exchange that for something they want to spend or buy in real life as well. So there's a whole divergence of how some of these experiences are going to come about, and for me it feels like we're starting to see the evolution of technology that we've all waited for and wanted for a long time. And I think that some of those use cases that I've talked to are just the beginning of what we're going to see from a creativity point of view.

BP Very cool.

[music plays]

BP All right, everybody. It is that time of the show. I want to shout out a Stack Overflow user who came onto the network and asked a stellar question. They were given the Stellar Question Badge, which means this question was bookmarked by a hundred users. Awarded five hours ago to G Revolution, “What is an antipattern?” Love it. If you don't know what that is, G Revolution asked the question and somebody else has provided the answer, so you can check it out in the show notes. Thanks G Revolution for coming on and spreading some knowledge around the community. I am Ben Popper. You can always find me on Twitter @BenPopper. You can always email us with questions or suggestions, And if you like what you hear, leave us a rating and a review. It really helps. 

RD I'm Ryan Donovan. I edit the blog here at Stack Overflow. You can find the blog at Stack And if you want to find me on Twitter, I'm @RThorDonovan.

MW And I've been Matt Woodward here, the Head of Developer Relations at Swirlds Labs, supporting the growth and development of Hedera. To find out more about Hedera, you can head over to Hit the start button there to find out more. If you'd like to search me out on Twitter, I'm also available as @WoodwardMatt on Twitter and I would welcome connecting with you.

BP Awesome. All right, everybody. Thanks for listening, and we will talk to you soon.

[outro music plays]