Arbitrum Rollout: Demo DeFi ecosystem built on Arbitrum’s Layer 2 testnet

Offchain Labs
3 min readJan 28, 2021


tl;dr: Porting to Arbitrum is easy. Check out a composable DeFi ecosystem on Arbitrum’s testnet. Building something on Arbitrum? Let us know and we’ll add it to the dashboard.

Since launching our permissionless, fully EVM-compatible Arbitrum Rollup testnet a few months ago, we’ve seen a flurry activity on our testnet and announced a few demo apps. Single app demos are nice, but don’t show the full power of Arbitrum’s composability. What we really wanted was a full L2 DeFi demo on Arbitrum that users can interact with. So, with the help of some amazing projects building with us on Arbitrum, we built it.

Head over to the dashboard and experience the power of DeFi on Arbitrum. Among teams building on Arbitrum and participating in this demo are Bancor , Bounce, Burgerswap, Hop, MCDEX (the first project to port onto Arbitrum!) and Swapr. In addition to those building on our testnet, we also internally ported a number of familiar DeFi favorites. Go ahead and mint ArbUSD on FakerDao and deposit it into a lending pool on Aarbe. Alternatively, you can add assets to liquidity pools on Arbiswap or check out some swaps on arBalancer.

The Layer 2 DeFi experience on Arbitrum is the same as Layer 1 with one huge difference: the cost. It’s just so much cheaper. How much cheaper you ask? Once you’ve submitted a transaction, head over to the Arbitrum block explorer to inspect your transaction and learn about its Layer 1 gas usage, the most significant cost for a Rollup that Arbitrum succeeds at minimizing.

While the dApps are important and certainly fun to play with, the ecosystem could not thrive without all of the familiar infrastructure that developers and users alike expect when interacting with Ethereum. Arbitrum currently works with many wallets including MetaMask, MathWallet, Burner, Portis and Fortmatic. You can also interact with Arbitrum through WalletConnect!

Many infrastructure providers are already advancing the Arbitrum ecosystem. Chainlink will be deploying its world-class oracle solutions on Arbitrum. Ankr will be deploying its node and developer API solutions on mainnet and Blocknative has provided support for Onboard. On the developer side, all familiar tooling, including The Graph, Truffle, Hardhat, ethers.js, web3.js and Brownie work right out of the box.

We are super excited to showcase this DeFi on L2 Demo to the Ethereum community and look forward to adding more projects. Do you have a project that you ported? Let us know and we’ll add it to the dashboard! The Arbitrum ecosystem is growing and we would love for each of you to be a part of that!

One important housekeeping note: We will be launching a new testnet in the next couple of weeks with some exciting significant upgrades! We will keep you all posted on our Twitter page and Discord, so definitely be on the lookout for that! Once that testnet is up and running, we will be moving this demo across to the new testnet.

We encourage all developers to actively explore and engage with Arbitrum. Our testnet is completely permissionless, and allows anyone to deploy their smart contracts without any changes. The best place to learn more about deploying on the testnet is here. Go ahead. Take a stab at porting your contracts and you’ll be surprised at how easy it is. And definitely reach out with any questions along the way.

Enjoy the demo and stay tuned for many more additions coming soon!