Leonardo Schwarzstein
Software Engineer at Edge & Node
Lisbon, Portugal
Summary
🤩
Rockstar🎓
Top SchoolLeonardo Schwarzstein is a software engineer with 11 years of experience, currently based in Lisbon and working at Edge & Node after a multi-year stint at The Graph. He specializes in backend systems, Rust, and runtime performance—evidenced by contributions to Graph Node, Rayon, DataFusion, and the Iron web framework where he optimized WASM execution, thread-pool stability, and router ergonomics. He’s an active open-source contributor who has shipped developer tooling and deployment features for The Graph’s subgraph ecosystem and helped harden foundational libraries used across the Rust ecosystem. A former co-founder, he pairs product-minded engineering with low-level systems expertise and a master’s in computer science from UNICAMP. Notably, his GitHub tagline “Taking Rustice into my own hands” reflects a focus on practical Rust tooling and runtime improvements that improve observability and deployability of blockchain indexing systems.
11 years of coding experience
4 years of employment as a software developer
Bachelor’s Degree, Computer Science, Bachelor’s Degree, Computer Science at Universidade Estadual de Campinas
Portuguese, English
Github Skills (44)
algorithm10
url-routing10
algorithms10
back-end-development10
multithreading10
macros10
data-parallel10
typescript10
system-design10
arrow-keys10
rust-wasm10
wasm-pack10
data-structure10
fusion10
subgraph10
Programming languages (19)
Github contributions (5)
graphprotocol/graph-node
Jun 2018 - Jan 2023
Graph Node indexes data from blockchains such as Ethereum and serves it over GraphQL
Role in this project:
Back-end Developer
Back-end DeveloperContributions:31 releases, 1310 reviews, 1385 commits in 4 years 8 months
Contributions summary:Leonardo refactored and optimized the runtime environment of the Graph Node, specifically focusing on the performance of WASM module execution. They modified the handling of block processing and data source creation, introducing code to handle memory allocation, and introduced new functions for managing the execution of smart contract calls. They also added logging for trigger data and the processing time of host functions for better debugging. These changes improved both the efficiency and the stability of the Graph Node's runtime.
node-graphipfsgraphql-apiindexesethereum
graphprotocol/graph-tooling
Jul 2018 - Aug 2022
Monorepo for various tools used by subgraph developers.
Role in this project:Full-stack Developer
Full-stack DeveloperContributions:31 reviews, 122 commits, 96 PRs in 4 years 1 month
Contributions summary:Leonardo primarily contributed to tooling for subgraph developers within a monorepo, focusing on enhancements to the CLI and runtime environments. Their work included resolving name collisions in event parameter generation, printing stack traces for codegen errors, and generating fixed byte tokens for function arguments. Furthermore, the user refactored and added deployment capabilities by implementing a `graph-deploy` command to compile and deploy subgraphs. They also made updates to improve example subgraphs.
monoreposubgraphgraphqlyarn-workspacestypescript
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