At KubeCon + CloudNativeCon Europe 2025, Cosmonic delivered one of the most compelling narratives on the limitations of today’s containerized Kubernetes ecosystem and how WebAssembly (Wasm) offers a future-forward solution for platform engineering and enterprise application development. In a talk described by attendees as one of the best of the show, Liam from Cosmonic laid out the case for why Wasm is not just an evolution—but a rethinking—of how we build, run, and secure cloud-native applications.
With a focus on enterprise WebAssembly, Cosmonic presented its new platform engineering product, the “Harness,” as a minimal, pluggable runtime that empowers developers to focus solely on business logic while platform teams handle complexity at scale. The company is making a clear case for why WebAssembly isn’t just an alternative to containers—it’s a superior model for many use cases.
Five Fundamental Failures of Containers
Cosmonic identified five systemic issues in today’s container-based Kubernetes world:
- Cold Starts – Even with optimization, containers like AWS Lambda still experience cold start delays. This becomes a cost and latency issue at scale.
- Bloat and Density – Containers often contain tens to hundreds of megabytes of dependencies, limiting the number of workloads per node.
- Portability Limitations – Dependency on the environment at the time of packaging makes containers less portable in practice.
- Operational Complexity – DevOps teams are forced to fix the same problems repeatedly across microservices, instead of solving them once through a platform approach.
- Security Challenges – Traditional container security models require external hardening; they lack native support for granular, capability-driven permissions.
WebAssembly addresses each of these with a “start-from-zero” philosophy, removing unnecessary features, starting small (e.g., a 7kB Go binary), and opting into capabilities progressively as needed.
Harnessing Platform Engineering for Business Logic
Cosmonic’s Harness product abstracts common platform needs—logging, tracing, HTTP interfaces, and security—into a reusable runtime just 255kB in size. Developers can drop in business logic, while platform teams maintain governance, policy, and observability across environments. This decoupling allows one platform team to fix 500 problems instead of 500 developers fixing one problem.
The Harness supports multi-language workflows, enabling teams to use the best tools for the job. Whether writing in Go, Rust, or JavaScript, all components leverage the same secure and scalable runtime. Teams can also define microservice templates with pre-approved policies and infrastructure bindings, accelerating development while ensuring compliance.
Security, Portability, and Bring Your Own Cloud
Cosmonic’s Wasm model emphasizes capability-driven security, where applications request specific permissions (e.g., access to a file system or user data) in a sandboxed execution environment. With support for WebAssembly System Interface (WASI) and upcoming CNCF WasmCloud standards, Cosmonic makes these capabilities enforceable at runtime.
Crucially, Cosmonic offers a “bring your own cloud” model: the control and data planes remain with the customer. Operators manage CRDs, policies, and workload identities across hybrid and multi-cloud environments, with seamless portability between control planes. Multitenancy—first- and third-party—is supported at the host level, reducing cost and complexity while maintaining isolation.
Real-World Adoption and Global Relevance
Cosmonic highlighted emerging use cases from sectors like financial services, telecommunications, and government. American Express is exploring WebAssembly for massive-scale workloads, while the Norwegian government’s Mattilsynet agency is using it to track livestock across regions. In telecom, Wasm is being adopted for 5G backend services such as charging stations and application controllers, thanks to its plug-and-play architecture and security-first model.
The open source community around Cosmonic’s efforts has grown from 80 to over 300 contributors in less than a year, signaling strong grassroots and enterprise interest. Companies are choosing WebAssembly to break free from legacy vendor lock-in and build better, more collaborative ecosystems.
Looking Ahead
Cosmonic’s vision for WebAssembly goes far beyond the hype: it offers a practical, powerful alternative to the limitations of containers in today’s Kubernetes environments. With a lightweight runtime, secure sandboxing, and a scalable platform engineering model, WebAssembly enables teams to build smarter, faster, and more securely.
As enterprises grapple with data locality, compliance, and rising infrastructure costs, Cosmonic presents WebAssembly as the right tool for a new era—one defined by precision, simplicity, and scale. The momentum from KubeCon EU 2025 makes clear that WebAssembly’s moment is here—and Cosmonic wants to lead the charge.
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