Scaling dApps in the rollup space is hard

Developers building on the Ethereum L1 had it easy - of course the OGs had to build from scratch and do the legwork for Ethereum to be where it is today, but... They have composability, atomicity, liquidity, and the benefit of network effects. 

The rollup-centric roadmap undoubtedly played a crucial role in scaling the L1, but due to its modular implementation, it also ended up fragmenting users, dApps, and liquidity across seemingly isolated islands. The cost of rollup fragmentation, if left unaddressed, can have a significant impact on smaller dApp teams and their potential users, as they pay the multivariate cost to bypass fragmented ecosystems.

The dApp developer’s reality check

If you’re planning to ship and scale in the L2 ecosystem, there are some choices you need to make:

• Which rollup ecosystem do you choose initially? 

• Do you have the resources to redeploy on another rollup to capture more users?

• Do you have enough liquidity to redeploy in multiple rollup ecosystems?

• Can the team manage multiple deployments across different tech stacks?

• How do you address onboarding friction for multiple deployments?

Building in the rollup ecosystem forces dApp teams into trade-offs they didn’t face on the L1. They must pick a rollup they want to initially operate in since dApps are only connected to other rollup ecosystems via bridges and not natively composable. Then decide whether they can afford to redeploy elsewhere to reach more users - splitting liquidity, incentives, and attention with each redeployment. Every new deployment adds infrastructure, audits, analytics, and complexity across different stacks for devs and their users. 

From a greater Ethereum perspective, being able to have all your users seamlessly use dApps between ecosystems without wait times and additional security and complexity is the ideal UX. Any token, on any dApp, on an chain, that’s the Compose North star.

Why build on Compose?

Developers building in the rollup ecosystem face a fundamental tradeoff: copy or compose. Compose eliminates that tradeoff entirely — letting dApps scale without sacrificing the network effects that made Ethereum L1 powerful.

Here’s what building with Compose unlocks for developers:

• Deploy once, Compose everywhere — Launch on your chosen rollup ecosystem, and your dApp becomes instantly reachable by users and liquidity from every other integrated or included rollup. No multi-stack redeployments or fragmented user bases.

• Access Ethereum-wide liquidity atomically — Your pools, vaults, or contracts can receive and route order flow across rollups in one atomic transaction.

• Plug into Ethereum-grade security — The Shared Publisher (SP) is powered by Ethereum validators, inheriting their neutrality and decentralization — no multisigs, relayers, or trusted bridge committees.

• Composable developer experience — Native SDKs and RPCs like eth_sendXTransaction make it as simple as batching calls across chains; Compose handles the atomic commit and ZK-proof aggregation under the hood.

• Predictable costs and deterministic UX — All cross-rollup legs are simulated and agreed on before commitment, so gas costs are known upfront and transactions either succeed everywhere or fail safely.

Want to learn more about Compose? Check out the beginners guide.

Practical implementations for developers

Cross-Chain Transactions — build complex cross-chain ops.

Craft two (or more) per-chain transactions and submit them as one atomic X-Transaction with eth_sendXTransaction. The tutorial shows a minimal ping/pong flow plus message encoding and bundle submission.

Bridging Assets — transfer tokens across chains.
Use Compose’s Bridge contracts to lock/burn on chain A and mint/release on chain B in a single atomic bundle; the guide walks through signing both legs, encoding the XT payload, and submitting via the custom RPC.

Composable dApps — production UX with UserOperations.
Go AA-native: create Kernel accounts + Multi-Chain ECDSA validators, sign once for both chains, build per-chain raw txs with compose_buildSignedUserOpsTx, then submit the X-Transaction and get per-chain hashes.

Custom Contract Development — Mailbox for cross-chain logic.
Import IMailbox in your contracts to write/read cross-chain messages directly while preserving atomicity; the doc includes a full example pattern and the two core mailbox methods. 

Solving the bootstrap problem

Compose mainnet will bootstrap synchronous composability for every rollup on Ethereum. The moment a rollup integrates Compose, its users get day-one access to the blue ocean of dApps and liquidity on the largest (Base, Arbitrum, Optimism, Polygon, etc.) and smallest L2 ecosystems. Those L2s simultaneously gain access to the newcomers. It’s a two-way street: your users can interact atomically, in one flow, with apps and assets across the network, and your dApp becomes instantly reachable by users from any integrated or included rollup. 

Compose solves the bootstrap problem: instead of rebuilding liquidity and network effects from scratch in each rollup ecosystem, you plug into them. For rollups and dApps that are not in the top 5 rollup ecosystems that capture the lion’s share of activity on Ethereum, this levels the playing field. Compose turns isolated economic islands into a truly interconnected Ethereum and sets the stage for a new rollup renaissance, where users, liquidity, and the best UX are available from the outset.

Stay tuned for public testnet

Developers can begin experimenting with Compose on the upcoming testnet (Q4 2025).
The testnet includes the following capabilties:

• Depositing funds to the shared deposit bridge.

• One-click cross-rollup swap e.g., Token on Rollup A (with no DEX) -> swap on Rollup B (with a DEX) -> swap back to Rollup A.

• Swap without holding liquidity on both rollups.

• One atomic transaction, finalized in minutes.

If you’re building dApps, get in touch, subscribe to the newsletter for updates and follow @ComposeNetwork to join devnets and co-design pilots. DMs are always open, let’s make Ethereum feel like one chain again.