# Heated Debate on Synchronous Composability in Blockchain Sector

Discussion around the utility of ‘Synchronous Composability’ has been heating up in the blockchain industry recently. This technology streamlines user experience by processing interactions between multiple chains instantaneously, facilitating seamless asset transfers between roll-ups and interactions between decentralized applications (dApps).

However, opinions are divided on whether this technology is essential in the current blockchain environment. Vitalik Buterin, co-founder of Ethereum, has criticized synchronous composability as an “overrated concept,” underscoring that an asynchronous approach can be equally effective.

To delve deeper into the utility and issues of synchronous composability, blockchain protocol firm Taiko hosted an in-depth discussion with industry experts, including Buterin.

> “Is synchronous composability overrated? Join us this Thursday to discuss with @VitalikButerin (@ethereum), @protolambda (@Optimism), @Brechtpd (@gwyneth_taiko), and @benafisch (@EspressoSys). Moderated by @arixoneth and @umedeyay.” – Taiko Gwyneth (@gwyneth_taiko), October 29, 2024

# Synchronous vs. Asynchronous Composability: What’s the Difference?

During the discussion, Taiko’s community lead, Erickson, described synchronous composability as “the state where multiple chains can exchange data simultaneously and validate results instantly without intermediary stages.”

In contrast, asynchronous methods process transactions and data at different times, introducing intermediary stages. On the current Ethereum mainnet, smart contracts are processed synchronously, allowing one contract to call another and receive results immediately. However, roll-ups predominantly use asynchronous methods, leading to latency in processes like asset transfers.

Taiko engineer Brecht Devos highlighted that synchronous composability can create structures where each smart contract on a roll-up network functions interactively, akin to the Ethereum mainnet. He emphasized that it enhances user experiences, especially when transacting assets across multiple chains.

On the other hand, asynchronous composability offers flexibility as each chain operates independently, though it may be limited by interaction speeds. Ben Fisch from Espresso Systems argued that asynchronous methods already provide sufficiently rapid transaction speeds, handling most use cases effectively while distributing liquidity across chains.

While synchronous composability can connect transactions quickly across different chains, it requires complex protocols and higher costs, making it somewhat restrictive.

# Vitalik Buterin’s Counterargument: Synchronous Composability is Overrated

Vitalik Buterin strongly opposed the necessity of synchronous composability, arguing that the experience can be replicated effectively through asynchronous approaches. He advocated avoiding excessive technical complexity.

For instance, he illustrated that through standards like ERC-7683, asset transfers between roll-ups can be completed within seconds, offering a user experience similar to transactions on a single chain. Implementing synchronous composability would necessitate various roll-up chains aligning to specific standards, potentially adding costs and complexity to the wider blockchain network.

Buterin emphasized that flexible user experiences can be delivered through asynchronous methods in the short term, promoting incremental improvements in a cost-effective manner.

# Standardization Challenges and Decentralization Concerns

The potential technical introduction of synchronous composability brings up standardization issues. Ben Fisch noted that a centralized sequencer might be needed to facilitate orderly transactions across different chains, which could compromise blockchain decentralization by centralizing transaction synchronization.

Brecht Devos mentioned that synchronous composability requires real-time verification systems and shared sequencers, which present speed and cost limitations under current verification systems. Taiko is considering zero-knowledge (ZK) proof-based verification to enhance security and efficiency, though recognizing that these technologies need further improvements in speed and cost.

# Advantages and Limitations of Asynchronous Composability

Both synchronous and asynchronous approaches have their strengths and drawbacks. Vitalik Buterin argued that asynchronous composability is effective enough in delivering a user experience that realistically renders the time lag (about one second) minor and often unnoticeable when moving assets across multiple chains. With standards like ERC-7683, most transactions can be managed asynchronously.

However, Fisch countered that synchronous methods might be necessary in specific scenarios. He remarked that while asynchronous composability effectively distributes liquidity across chains, synchronous approaches could better address liquidity issues in single transactions involving multiple chains. Additionally, in cases of NFTs or individual asset distributions, asynchronous composability may struggle to achieve perfect composability.

# Technological Advancements and Blockchain Improvement

Brecht Devos indicated that significant technical advancements are required before synchronous composability becomes commercially viable. He predicted that improvements in ZK proof technology could eventually support real-time verification, enhancing blockchain security and efficiency.

Nevertheless, Fisch reiterated that until ZK proof technology becomes fully practical, asynchronous methods could solve many present-day issues, offering rapid transaction speeds and benefitting large-scale liquidity distribution. He advocated for maximizing the flexibility of asynchronous methods as a more realistic solution for current blockchain networks.

# Practical Needs and User Experience Enhancement

The discussion concluded by weighing the benefits and technical challenges of implementing synchronous composability. While it has the potential to smooth interactions across roll-up chains and enhance user experiences, experts like Buterin stressed the importance of assessing cost-efficiency.

The blockchain industry continues to engage in vibrant technical debates over synchronous and asynchronous approaches, which are crucial for shaping the future direction of technology development. Attention is focused on whether synchronous approaches will see the necessary technical advancements for commercialization or if optimized asynchronous methods will become the preferred solution for blockchain networks.