My name is Carlo Sala. I am a software engineer and open-source maintainer focused on developer tooling and client-side infrastructure for the Polkadot ecosystem.
I am a maintainer and developer of Polkadot-API, a suite of TypeScript libraries designed around a light-client-first approach to building applications for Polkadot SDK-based chains. My work is centered on making interaction with Polkadot reliable and type-safe for developers, while staying aligned with the underlying protocol and runtime interfaces.
My background combines software engineering, open-source maintenance, and mathematics. I also maintain open-source software through Oh My Zsh, which has given me long-term experience with public collaboration, review processes, and widely used developer-facing tooling.
I am applying to the Polkadot Technical Fellowship because I want to contribute more directly and consistently to the technical evolution of Polkadot.
Most of my work sits at the boundary between protocol/runtime behavior and the developers who build applications on top of it. Through Polkadot-API, I regularly deal with runtime metadata, transaction construction, signing, RPC behavior, XCM-facing APIs, and light-client integration. This has made clear to me how important close coordination is between runtime engineers, SDK contributors, tooling maintainers, and application developers.
Joining the Fellowship would give me a more structured way to participate in those technical discussions, share implementation feedback from the tooling side, and help improve the interfaces that developers rely on when building on Polkadot. I want to bring downstream implementation feedback into Fellowship discussions earlier, especially when changes to metadata, extrinsics, RPCs, or runtime interfaces affect wallets, light clients, and application tooling.
I also see the Fellowship as a long-term commitment mechanism. I want to be accountable to the technical community around Polkadot and to continue contributing in a way that is visible, reviewable, and useful to the ecosystem.
My main areas of interest in the Polkadot ecosystem are:
My primary contribution to the Polkadot ecosystem is my work on Polkadot-API. Polkadot-API provides a composable TypeScript library stack for interacting with Polkadot SDK-based chains, with a strong focus on light-client usage, type safety, and developer ergonomics.
Within Polkadot-API, my work includes API architecture, light-client-focused design, runtime metadata integration, typed interfaces, application-facing abstractions, and upstream coordination when SDK or runtime behavior affects downstream tooling. The goal is to make it practical for application developers to build against Polkadot chains using modern TypeScript tooling while preserving correctness and compatibility with the underlying chain interfaces.
I have also contributed directly to paritytech/polkadot-sdk, including merged pull requests such as:
The metadata v15 fix was also backported across multiple release branches. These SDK contributions are closely connected to my Polkadot-API maintenance responsibilities, where SDK changes often have direct impact on application developers and client libraries.
In polkadot-fellows/RFCs, I have contributed to protocol and interface discussions around metadata, transaction formats, and offline signing. In particular, I contributed as a co-author to #78: Merkleized metadata, and I opened #148: RFC-0078 adaptation to Metadata V16 and Extrinsic V5 to continue the discussion around Metadata V16, Extrinsic V5, and the information offline signers need in order to decode and verify transactions correctly.
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