Building the Future of Money — From Zero to DeFi Protocol on Network

In 2023, Silicon Valley Bank collapsed in forty-eight hours. Two hundred and nine billion dollars in assets, gone. Credit Suisse, an institution that had survived two world wars and a hundred and sixty-seven years of market cycles, was absorbed over a single weekend. Inflation across the Western world reached levels unseen in four decades. Trillions of euros and dollars sat in bank accounts earning nothing while the purchasing power of savers eroded month by month, statement by statement.

People stopped trusting the institutions that had failed them. Not out of ideology — out of self-preservation. They wanted transparency. They wanted security they could verify, not promises they had to believe. They wanted their money to work for them, not against them.

That is the context in which I opened my terminal and started writing code.

Why Stablecoins. Why USDC. Why Now.

Not all stablecoins are created equal. Some are opaque, backed by assets no one can independently audit. Others are managed by entities with no regulatory oversight and no obligation to disclose what sits behind the peg. The history of crypto is littered with stablecoins that turned out to be stable in name only.

USDC is different. It is issued by Circle, a company publicly traded on the New York Stock Exchange. Its reserves are audited monthly by independent accounting firms. Every USDC in circulation is backed one-to-one by cash and short-dated US Treasury bills — the safest financial instruments on the planet. When Silicon Valley Bank nearly dragged USDC into its collapse, Circle covered the gap within hours, not weeks. That is the difference between a stablecoin that claims stability and one that proves it under pressure.

And then there is USYC — US Yield Coin. For the first time, the yield generated by US Treasury bills is accessible directly on-chain. This is not speculative DeFi with three-digit APYs that evaporate overnight. This is real yield, backed by the sovereign debt of the United States. The same return that institutional money market funds earn, but programmable, composable, and accessible to anyone with an internet connection.

Security and trust are not optional features. They are the foundation on which everything else is built.

Then Circle Launched Arc

October 28, 2025. Circle launched the Arc public testnet.

Not just another Layer-1 blockchain. The first chain built by a stablecoin issuer, designed from the ground up for finance. BlackRock, Visa, HSBC, Deutsche Bank, and Mastercard among the testnet partners. USDC as native gas — no exotic token required to transact on the network. Sub-second finality. Native integration with the full Circle stack: CCTP for cross-chain transfers, Teller for tokenized assets, Gateway for fiat on-ramps, Paymaster for gasless transactions.

More than a hundred institutions began exploring the testnet on day one. For the first time, a blockchain launched with more financial credibility than crypto hype.

When I saw the announcement, I knew this was where to build. Not because it was trendy — because for the first time, a blockchain had been conceived with real finance as its reason for existing. Not as an afterthought. Not as a feature bolted on after the fact. As the network's core purpose.

Day One — A Developer, A Terminal, and 107 Days of Building

I started on October 28, 2025. The same day the public testnet launched.

There was no team of fifty engineers. No Series A funding. No office with standing desks and kombucha on tap. There was me, my brother helping review code and working on the interface, and an idea that kept us awake far later than reason would advise.

The idea came from a trip to Belgium. In Belgium, workers are paid weekly, not monthly. That simple observation planted a question I could not let go of: why stop at weekly? Why not daily? Hourly? Every second?

Imagine a world where your salary flows to your account in real time. Every second, you earn. Every second, you can withdraw what you have already accrued. No paycheck locked away for thirty days. No advance to request from an employer. A continuous, transparent, programmable flow. A world slightly more free, slightly more fair.

That is the vision behind the first line of code that would become Meridian Finance.

Twenty-six days. Twenty-six days of writing code, morning to night and often through the night. Falling asleep at four in the morning, waking at eight. Eyes red, glued to the screen. My computer overheating so badly that I had to set it next to an open window in the middle of winter just to cool it down enough to keep going. The time difference with the Circle team in the United States meant their responses arrived as I was falling asleep, and I woke up to solutions that needed immediate implementation.

On November 23, 2025, the first deployment went live. Smart contracts integrating USYC on Arc Network. The first DeFi contracts whitelisted by Circle on their new blockchain.

But that first deployment was just the beginning. Twenty-six days to get the first contracts live — then another eighty-one days of relentless iteration. Twenty-eight contract deployments on Arc Testnet, each one refining the architecture. Testing, breaking, fixing, redeploying. Upgrading from V1 to V2, then V3. Implementing UUPS proxy patterns so the contracts could be upgraded without losing state. Adding Timelock governance so no single key could modify the protocol. Running Slither and Mythril audits after every major change. By the time the contracts reached their final form, there were twenty-eight deployments behind them — each one a lesson learned, a vulnerability patched, a design decision validated. 107 days of continuous building. And counting.

We were not the first builders on Arc. But we were the first to deploy smart contracts integrating USYC for yield infrastructure.

Building With the Full Circle Stack

What makes Meridian Finance different is that we did not simply deploy a smart contract on Arc. We integrated every layer of the Circle stack, one by one, understanding how each piece fits together.

The ERC-4626 Yield Vault is the core of the protocol. Users deposit USDC, and the vault converts it into USYC through the Circle Teller. The yield from US Treasury bills accumulates automatically. No exotic staking mechanisms, no degenerate farming strategies — sovereign yield, on-chain. And soon, EURC — thanks to Circle StableFX, an institutional-grade on-chain FX engine that enables instant, atomic conversion between stablecoins directly on Arc. A $7.5 trillion-per-day forex market, rebuilt on-chain — 24/7 settlement, no prefunding, no bilateral agreements. Euros to dollars and back, in seconds.

Payment Streaming transforms payments into continuous flows. Instead of sending five thousand USDC on the thirtieth of the month, the contract streams the payment by the second. The recipient can withdraw at any moment what they have already earned. And while the funds flow toward the recipient, they continue generating yield in the vault. The money works until the very last second.

CCTP — the Cross-Chain Transfer Protocol — enables USDC movement between chains without third-party bridges. Ethereum, Polygon, Arbitrum, Base, Optimism, Avalanche — users on any of these networks can deposit directly into Meridian on Arc.

Gateway and Paymaster make transactions gasless. The user never pays gas fees. Ever. The experience is as smooth as a traditional fintech application.

And then the Modular Wallets with Passkeys — the final piece of the puzzle. Face ID on iPhone. Fingerprint on Android. Google password manager on desktop. No seed phrase to back up. No browser extension to install. A face scan and you have a smart account deployed across eight chains simultaneously. The same address everywhere. This is what onboarding the next billion users looks like.

Every contract is deployed, whitelisted by Circle, and fully verifiable on-chain. Here are the live smart contracts on Arcscan, the official Arc Network block explorer powered by Circle:

Both contracts are EIP-1967 upgradeable proxies — permanent addresses, upgradeable logic. Fully transparent, fully on-chain, fully auditable by anyone.

Built on

The Hard Parts Nobody Talks About

Twitter threads only show the victories. Here is what they leave out.

The circle_getAddress error that blocked us for days. The smart account refused to deploy. The error message — "method does not exist" — told us nothing useful. We checked everything. The configuration. The API keys. The dependency versions. Everything appeared correct. The bug? A slash. A single missing character in the transport URL — the chain path was not appended to the bundler endpoint. Days of debugging for one slash.

The BridgeKit returning errors on certain chains with no explanation. UserOperations that failed silently — no error, no revert, just nothing. The whitelisting process that demanded patience while every day without approval was a day unable to test under real conditions.

The Slither and Mythril audits revealing vulnerabilities you were certain you had covered. That feeling when the tool tells you your contract has a reentrancy risk on a function you have reviewed twenty times.

And the rebrand. USYC is a registered trademark of Circle. Our original name — USYC Protocols — had to change. What could have been a setback became the best pivot we made. Meridian Finance. A meridian is a line that connects two points on the globe. That is exactly what we are building: a bridge between traditional finance and DeFi. Between the Treasury yields of Wall Street and a developer on the other side of the world who wants to put their USDC to work.

Building in production, even on testnet, means accepting that things will break. The question is not if, but when. And when it breaks at three in the morning, there is no one but you and your terminal.

The Numbers

No vanity metrics. Real figures, on a testnet, for a protocol built by a small team with no funding and no marketing budget.

For context: Jeremy Allaire, the CEO of Circle, shared our work — "Agents need yield too!" Mario Nawfal, with over three million followers, shared our YieldClaw agent. The signal was clear: what we are building resonates beyond our own community.

These numbers are not the destination. They are the first coordinates of a trajectory.

What's Next

Meridian Finance is not finished. We are only laying the foundations.

The Circle on/offramp integration is the next step — allowing anyone to go from fiat currency to DeFi yield in a single click. No complicated crypto transfers, no intermediate exchange. Euros or dollars, directly into a yield vault.

A professional smart contract audit by a recognized security firm. Multi-sig governance so that no one — not even the founder — can unilaterally modify the contracts. An institutional dashboard with full accounting exports, PDF and CSV with legal disclaimers — already functional on testnet.

And further out, personal agents. Every Meridian Finance user will be able to have their own yield optimization agent. An autonomous agent that monitors rates, compounds returns, rebalances positions, and manages scheduled payments — all without human intervention.

Arc mainnet is approaching. When it goes live, Meridian Finance will be ready.

Be an Early User — We're Tracking On-Chain

During this testnet phase, every interaction with Meridian Finance is recorded on-chain. Deposits, withdrawals, stream creations, yield claims — all of it is permanently tracked on Arc Network. Early users who test the protocol now will be recognized when mainnet launches.

Getting started takes less than a minute. Circle provides a free testnet faucet where you can claim 20 USDC on Arc Testnet — no cost, no risk. Connect your wallet to Meridian Finance, deposit your testnet USDC into the vault, and start earning simulated Treasury yield. It is that simple.

This is not a speculative airdrop promise. This is a verifiable on-chain footprint. Your address, your transactions, your history — all immutably stored on the blockchain, visible on Arcscan.

We started with a simple idea: money should work for people, not the other way around. Finance should be transparent, verifiable, and accessible to everyone — not reserved for those with the right connections or the right postal code.

A developer with a vision and code can build something that matters. Not from a garage in Silicon Valley. From anywhere in the world, on a blockchain designed for real finance, with tools provided by a company that takes regulation seriously.

Arc Network is not just another blockchain. It is the infrastructure on which the next generation of financial services will be built. And Meridian Finance will be one of the protocols that makes it work.

If you are reading this, you are still early.