On Solana, almost every transaction that needs to land during congestion runs through infrastructure one company built. Jito's client sits under more than 95% of active stake, and its tips have grown to the majority of the network's real economic value, the closest thing the chain has to a monopoly on who gets into a block, and what that access costs. \That cost isn't abstract: priority fees can spike as much as 100x in a volatile session, and a U.S. class action now alleges billions in retail losses tied to how Solana orders transactions. One provider controls the orderflow layer; one set of rules governs who wins.\Flowra wants to prise that market open, on a claim that sounds backwards: expose orderflow to more competitors, and validators earn more, not less. It's the bet Ethereum already ran and won. Today, Ishan Pandey sits down with Harry Hwang, CEO and co-founder of Flowra, for HackerNoon's "Behind the Startup" series.\ \The through-line: from trading on top to building underneathIshan Pandey: Harry, welcome. You have had an unusual path: derivatives prop trading at a traditional finance desk, then CeFi quant trading, then DeFi, then building Mevity, a block-building company focused on helping validators increase their rewards, and now founding Flowra. Each of those moves represents a fairly sharp pivot. What was the through-line in your thinking, and at what point did you decide that building infrastructure was more interesting than trading on top of it?\Harry Hwang: Thanks for having me today. I understand it sounds like a series of random pivots, but it has always been about chasing risk-neutral opportunities. At the prop trading firm, I was primarily running pure statistical arbitrage strategies, not so much in the DeFi space. Even after transitioning into DeFi, I had the privilege of having a front-row seat to understanding what validators and the broader ecosystem actually wanted and needed.\It became clear to me that the infrastructure layer underneath held bigger and more fundamental unsolved problems than the trading layer on top. In a way, my experience at large financial institutions also gave me an appreciation for just how important compliance is if traditional financial institutions are going to participate in this space. That perspective heavily influenced how we built Flowra as a decentralized infrastructure with compliance at its core.\I genuinely felt we were the right team to solve what the Solana ecosystem needed next, and that conviction is what ultimately led to Flowra.\ Ishan Pandey: Mevity onboarded roughly 4 million SOL of validator stake as a block-building operation focused on increasing validator rewards. Most founders would have kept building on that. What did you observe from inside a top-tier block-building operation that convinced you the deeper opportunity was the infrastructure layer itself rather than operating on top of it?\Harry Hwang: I'd frame it less as hitting a ceiling and more as seeing the next chapter clearly. Building Mevity was an incredible experience for us. We were fortunate to have major CeFi exchanges and institutional validators onboard, and our early results were very promising. But having such a close view of what validators actually needed from block building revealed a much larger and more scalable opportunity.\That realization led us to pivot toward building the underlying infrastructure. Creating a block engine that is more auditable, competitive, and compliant ultimately became the core mission behind Flowra.\The mechanism: why more competition pays validators moreIshan Pandey: Walk us through the mechanism: how does making orderflow visible to more searchers actually produce more revenue for validators rather than simply compressing margins through competition?\Harry Hwang: It seems counterintuitive, but increased competition compresses searcher margins, not validator revenue. On Solana, order flow is typically only visible to validators or private providers like Jito, allowing a small number of searchers to capture most of the MEV while paying relatively low tips. Flowra makes order flow visible to multiple searchers simultaneously, creating competitive bidding for the same opportunity. As a result, a much larger share of the MEV is paid to validators as tips, while searcher profits are competed down toward operating costs. This dynamic has already been validated on Ethereum with MEV-Boost, and Solana's higher throughput and faster block times make the effect even more pronounced.\ The reporting behind this: Harry's mechanism isn't just theory, Ethereum ran the experiment. Proposer-builder separation (MEV-Boost) opened block construction to a competitive market of builders, and a peer-reviewed empirical study measured a +261% increase in proposer (validator) revenue afterward. The logic is specialization plus competition: builders bid away most of the value to win the right to have their block proposed, so the proposer captures MEV indirectly, by auctioning blockspace rather than extracting it personally.\\ \Ishan Pandey: Jito controls roughly 72% of staked SOL and has raised $12.1 million in total funding. You are entering this market at launch with approximately 60 million SOL already committed to migrate. What is the real switching cost for a validator moving from Jito to Flowra, and why are institutional validators, who have every reason to be conservative, willing to route stake through you before you have a live performance track record?\Harry Hwang: For several reasons, honestly.First, the experience we built through Mevity has been our most valuable asset. We weren't entering the market as just another infrastructure vendor. We had already spent significant time working alongside validators on block building, and those relationships gave us a very different starting point for those conversations.\Second, we see the evolving regulatory landscape around digital assets as a major opportunity. As more traditional financial institutions enter the space, compliance will become increasingly important. Coming from a TradFi background ourselves, we understood early on that institutional participants would need infrastructure with built-in compliance capabilities. That's exactly what Flowra's Programmable Block Policy (PBP) is designed to provide.\Third, an open mempool doesn't just improve transparency, auditability, and user protection against excessive fees, it also creates the potential for significantly higher validator yields by enabling a more competitive transaction marketplace.\We're encouraged that this thesis resonates across multiple dimensions, and we're grateful for the traction and support we've seen so far.\"A sandwich-attack factory with better branding?"Ishan Pandey: The open mempool framing is a double-edged sword. The first question any serious validator or searcher will ask is whether this is essentially a sandwich-attack factory with better branding. How does Programmable Block Policy enforce ethical MEV at the infrastructure level in practice, and what prevents a validator from simply switching those protections off?\Harry Hwang: I'm glad you brought that up because it's something we think about a lot.\At Flowra, we believe the right approach isn't to pretend MEV can be eliminated, but to shape it into something that benefits the ecosystem while protecting users. That's where our Programmable Block Policy (PBP) comes in. It serves as the foundation of our compliance framework, allowing validators to enforce policies required by financial institutions, such as sanctions screening and AML requirements, while also mitigating harmful forms of MEV directly at the infrastructure layer.\From day one, PBP is designed to prevent single-bundle sandwich attacks, and we're continuously expanding its capabilities to address more sophisticated forms of predatory MEV. For us, these protections aren't optional features, they're baseline requirements for building infrastructure that institutions can trust.\That said, we don't believe MEV itself is inherently bad or something that can be completely removed. MEV is a natural byproduct of blockchain design, and attempts to eliminate it entirely often just drive it into less transparent channels. The more important question is whether the incentives around MEV are aligned with the long-term health of the network.\Many forms of MEV, such as atomic arbitrage, liquidations, and healthy back-running, actually improve market efficiency and contribute to price discovery. Our objective is to preserve those beneficial mechanisms while systematically reducing extractive behavior that comes at the expense of users. In other words, we want to build infrastructure where transparency, compliance, and healthy market dynamics reinforce one another instead of competing.\ The reporting behind this: the stakes here are large and now legal. A U.S. federal court has allowed a class action against Pump.fun, later expanded to include Solana Labs, the Solana Foundation and Jito Labs, to proceed; it alleges $4.4–5.5B in retail losses tied to MEV and transaction ordering, a figure the court has not verified. Whatever the final number, it is why "fair ordering" on Solana has become an economic and regulatory question, not just a technical one.\ \The business: beyond the tip feeIshan Pandey: Price alone rarely wins a structural market. Where does Flowra's revenue model go beyond the tip-fee, and what does the long-term business actually look like: the mempool API, the validator client, or something else entirely?\Harry Hwang: Our core argument isn't about competing on fee rates. It's about growing the size of the pie itself. Because the total tip volume generated within Flowra's OOA network is larger, both validators and Flowra earn more in absolute terms without having to compete solely on fee rates. A smaller share of a much larger pie is still worth more.\Looking further ahead, we see three primary revenue streams. The first is the protocol tip fee, which exists today. The second is the open order flow data stream itself. Real-time mempool data has independent value for trading firms and institutions, making it a meaningful revenue layer in its own right. The third is institutional services built around Programmable Block Policy (PBP). Exchanges and financial institutions that want to operate Solana validators require compliance-grade block policy infrastructure, and that capability doesn't meaningfully exist today. Providing it represents a distinct business opportunity.\At this stage, however, our primary focus is on growing the network and expanding the transaction marketplace. As that foundation scales, the revenue model naturally scales with it.\ \The honest case: why not simply the next Jito?Ishan Pandey: Final question: validators chose Jito voluntarily because it paid better, not because they were forced. The dependency was economic, not coercive. What is the honest case for why Flowra is structurally different rather than simply the next dominant provider in the making, once the network effects kick in?\Harry Hwang: That's a fair question. I agree with the premise that validators chose Jito because it delivered better economics, not because they were forced to. If Flowra builds a better product, we hope validators will choose us for the same reason.\The difference we're trying to build is structural rather than purely commercial. We can't promise that Flowra will never become large or successful, but we can design the infrastructure so that success doesn't create the same kind of dependency.\The first difference is our Open Orderflow Architecture (OOA). Because the transaction marketplace is open, the information and access that competitors need to build alternative infrastructure are available from day one. If someone believes they can build a better block engine or offer a different value proposition, they don't have to start from scratch or rely on privileged access. That's a fundamentally different foundation from a closed transaction marketplace.\ \ The reporting behind this: this is the right question to end on, because Ethereum shows the precedent cuts both ways. Proposer-builder separation raised validator revenue sharply (+261%) — but the same open market re-concentrated: today the top three builders win more than 95% of MEV-Boost auctions, and private orderflow (~12% of transactions) came to carry ~54.6% of block value. Open architecture lowers the barrier for challengers; whether it stays open depends on resisting the exclusive-orderflow deals that re-centralized Ethereum. That is the bar Flowra has set for itself.\The second difference is Programmable Block Policy (PBP). Validators retain control over their own block policies — whether that's compliance requirements, bundle restrictions, or other operational preferences. Those policies belong to the validator, not to Flowra. That gives validators real autonomy rather than requiring them to adopt a single provider's view of how blocks should be built.\ Finally, we think the market itself is evolving. As digital asset regulation matures and more financial institutions enter the ecosystem, compliance will become a competitive requirement alongside economics. Our goal isn't simply to be the highest-paying block engine. It's to provide infrastructure that is transparent, compliant, and economically competitive while remaining open enough for others to compete with us. If we've built the system correctly, our success shouldn't come from locking others out, it should come from building the best infrastructure in an open marketplace.\Don't forget to like and share the story!:::tipVested Interest Disclosure: HackerNoon has reviewed the report for quality, but the claims herein belong to the author. #DYOR.:::\\