Cross-Chain: A Delicate Balance of Innovation and Risk The Inter-Blockchain Communication (IBC) protocol is widely regarded as one of the most promising solutions for achieving true blockchain interoperability

When people talk about Web3, they're usually referring to individual blockchain platforms — Ethereum, Solana, Polkadot. But true decentralization, along with real scalability, begins not within these isolated ecosystems, but at the points where they connect. Making these networks interoperable requires "bridges" — technical solutions that enable the transfer of assets and data across blockchains, even when those systems are built on fundamentally different architectures.

Vladislav Markushin is one of the few engineers in the space focused exclusively on these complex cross-chain infrastructures. Over the past several years, he's led development at Composable Foundation, where his team became the first to successfully adapt and implement the Inter-Blockchain Communication (IBC) protocol — originally designed for the Cosmos ecosystem — to work across Ethereum, Solana, and Polkadot. It was the first deployment of IBC outside Cosmos, extending one of the most advanced interoperability standards to entirely different architectures.

In this interview, Vladislav breaks down how secure cross-chain systems are actually built, why full decentralization requires a radically different engineering mindset, and what it takes to ensure direct blockchain-to-blockchain interaction — without intermediaries, and without compromise.

Why Blockchain "Bridges" Aren't Just a Metaphor — They're a Serious Engineering Challenge

At first glance, the concept seems simple: a user wants to transfer assets from one cryptocurrency network to another — say, from Ethereum to Solana. But in practice, it's more like trying to move a file from a modern laptop to an old-school calculator. The underlying architectures are completely different, the programming languages don't match, and, most importantly, there's no built-in trust. Blockchains are inherently isolated; they don't "see" each other and reject any external data unless it's verified through their own internal consensus mechanisms.

The technologies that make these transfers possible fall under the umbrella of what's known as cross-chain infrastructure — a broad term covering the tools that enable communication between otherwise siloed blockchain networks. In theory, this infrastructure could turn Web3 into a seamless, interoperable ecosystem rather than a patchwork of disconnected platforms. In reality, though, cross-chain infrastructure is one of the most technically challenging — and vulnerable — areas in blockchain development.

To date, most cross-chain systems still rely on what's called a trusted approach. This model uses third-party intermediaries — such as smart contracts, multi-signature wallets, or centralized exchange infrastructure — to manage communication between blockchains. It's a setup that streamlines development and accelerates transactions, which helped it gain traction early on. But as the volume of cross-chain activity increased, so did the risks. Some of the most high-profile hacks in Web3 — including attacks on the Binance Bridge and Ronin — have exploited these trusted systems.

Vladislav began his career working extensively with these trusted models. At the time, they were the most viable solution from a technological standpoint. That hands-on experience proved invaluable, offering a close-up view of the trade-offs and vulnerabilities built into the system. It also inspired him to think differently.

Today, Vladislav leads the development of trustless infrastructure at Composable Foundation — systems where validation happens directly on the blockchains themselves, without any middlemen. Building this kind of architecture demands rigorous engineering: aligning protocols, developing robust cryptographic proofs, and ensuring security at every step. But for Vladislav, it's a necessary evolution. It's how blockchain networks can finally communicate with each other in a way that's secure, decentralized, and truly aligned with the original ethos of Web3.

How IBC Is Changing the Way Cross-Chain Solutions Are Built

The Inter-Blockchain Communication (IBC) protocol is widely regarded as one of the most promising solutions for achieving true blockchain interoperability — enabling different blockchain networks to communicate and operate together seamlessly. Originally developed within the Cosmos ecosystem, IBC allows independent blockchains to transfer tokens and data between one another directly, securely, and without relying on centralized intermediaries. Instead, all verification takes place at the application (smart-contract) layer of each participating blockchain.

Unlike centralized bridges — which typically involve mirroring actions across networks via smart contracts — IBC introduces a fundamentally different model. It operates more like a universal messaging protocol, akin to how TCP/IP enables the internet. As long as two blockchains support IBC, they can interact — regardless of how different their internal architectures may be.

"This represents a genuinely radical shift compared to previous solutions," says Vladislav - "IBC eliminates the need for external confirmations by third parties. Every verification step occurs directly within the chains themselves, using finalized blocks and cryptographic proofs. For users, that means they no longer need to trust intermediaries — just the integrity of the blockchains they're using."

Vladislav and his team were the first to extend IBC's capabilities beyond the Cosmos ecosystem. They successfully adapted it to work with Ethereum, Polkadot, and Solana — networks that weren't originally built with this form of interoperability in mind. This milestone required extensive engineering: from developing specialized relayer that transmit messages between blockchains and contracts to light-clients, to modifying validator logic and creating indexing and synchronization tools tailored to each platform.

Each blockchain posed its own unique challenges. For Ethereum, the team integrated zero-knowledge proofs. For the Solana Rollup, they modified validator node software. For Polkadot, they developed custom Substrate-based modules. Despite these differences, all the efforts shared a common goal: enabling decentralized, verifiable communication between chains.

By this point, Vladislav was leading the engineering team — overseeing multiple bridge deployments and designing the core infrastructure that would support them. Adapting IBC to such varied networks wasn't just technically ambitious; it was a natural next step for someone whose career had been shaped by years of grappling with the complexities of blockchain interoperability.

From Startup Projects to Infrastructure: How Vladislav's Engineering Perspective Took Shape

Vladislav's journey began with a student startup, where he helped build a mobile cryptocurrency messenger called Paymon. The team developed iOS and Android apps for sending digital assets, launched a full backend system, and raised over $500,000 through an ICO. While the product didn't evolve into a commercial success, the experience shaped his approach to systems architecture. A turning point came when they rewrote an integration with IOTA from Java to Rust — a shift that sparked Vladislav's focus on security, performance, and low-level design.

After Paymon, he joined Bitfury, where he worked on a wide range of blockchain applications for enterprise clients. His work included developing a loyalty platform, a government-backed diploma storage system, and a middleware layer for database replication. He also integrated GOST encryption standards into the Exonum Enterprise framework and optimized CI/CD pipelines — reducing build times by 50%.

These projects gave him a hands-on view into how blockchain could be used outside of cryptocurrency. From bridges to backend services, Vladislav built systems that supported real-world use cases. That breadth of experience laid the foundation for his later work in cross-chain architecture — where security and interoperability must be engineered from the ground up.

Navigating Technical Trade-Offs

One of the most persistent challenges in cross-chain development is balancing convenience and security. Centralized bridges are faster and more cost-efficient — but often less secure. Trustless solutions like those built on IBC offer a higher degree of security but come with steeper resource requirements and longer development timelines.

"Users want fast, cheap transfers," Vladislav says. "But for institutional use cases, reliability and security matter far more. That's where we focus — environments where the stakes are too high for shortcuts."

Even internally, engineering teams must weigh the trade-offs between delivering quickly and building with perfection. Vladislav acknowledges that sometimes deadlines force difficult choices. When that happens, the team prioritizes mission-critical components, while postponing or simplifying secondary features.

What matters, he notes, is that any technical debt incurred is rigorously documented and revisited — ensuring that temporary compromises never become long-term weaknesses.

On Technical Leadership

Leading a team in multi-blockchain development presents unique challenges. Unlike traditional engineering teams working within a unified stack, each developer here specializes in a different ecosystem — whether it's Solidity, Rust, or Go. For Vladislav, the key to making this structure work is minimizing context switching and encouraging deep specialization. Developers should focus on mastering their chosen platform, allowing them to work more efficiently and with greater confidence.

This approach not only increases productivity but also promotes accountability. When engineers are trusted to own their domains, they become more invested in the quality and reliability of what they build.

One particularly revealing moment came right before the launch of a major cross-chain bridge. The team encountered a critical issue they couldn't immediately solve. Surprisingly, it wasn't their strongest coder who broke through — it was a developer with strong community connections who reached out externally and found a solution through their network.

"That really reshaped my thinking," Vladislav says. "Great engineers aren't just defined by technical skill. Curiosity, initiative, and the ability to look beyond your immediate team — those are just as important. As a team lead, you need to create an environment where those qualities are recognized and encouraged."

To make that possible, Vladislav focuses on fostering a culture of transparency and trust. Engineers are given the space to explore and take initiative, but also guided by a clear shared vision — so that even across different tech stacks, everyone is still building toward the same end.

What's Next: Trends and Challenges

Looking ahead, Vladislav sees two key challenges shaping the future of multi-chain systems: scalability and usability. On the technical side, emerging technologies like Zero-Knowledge (ZK) proofs promise to reduce network load while enhancing privacy. These cryptographic tools enable secure validation of transactions without revealing the underlying data — a major step forward for both efficiency and confidentiality.

At the same time, Vladislav emphasizes the importance of user experience. Today's cross-chain systems still demand technical know-how that excludes many potential users. Making these tools more intuitive — through better UX design, smoother onboarding, and tighter integration with existing Web2 systems — is essential for broader adoption.

"Scalability and privacy are important," he says, "but if only developers can use your product, it's not infrastructure — it's a prototype."

Beneath these challenges, a deeper goal remains constant: eliminating the need for trust altogether.

"We're building systems where you don't need to trust anyone — not an exchange, not an operator, not even a smart contract. The only things you rely on are the protocol and the math behind it," Vladislav explains.

It's a more difficult path, he admits. But in a field where the stakes are high and the risks real, it's the only path that makes sense long term.