Felix Lange
Full Stack Developer at NetTask GmbH
Oberlungwitz, Saxony, Germany
Summary
🤩
Rockstar🎓
Top SchoolFelix Lange is a seasoned full stack developer with 17 years of hands-on experience building and hardening backend systems, currently based in Oberlungwitz, Saxony and working at NetTask GmbH. He is a pragmatic engineer with deep contributions to high-profile blockchain projects (go-ethereum, ethash, erigon, aleth, bsc) where he focused on performance, concurrency, P2P networking and security. Felix also contributes to developer tooling and language ecosystems—improving Emacs LSP, Go CLI libraries and packaging Common Lisp for Termux—showing fluency across languages and runtimes. His work often targets subtle, reliability-driving problems (RPC robustness, DAG/cache synchronization, consensus test harnesses) rather than surface features. Known on GitHub as a "Chief Stacktrace Designer," he combines low-level systems thinking with practical DevOps automation to keep distributed systems running.
17 years of coding experience
Ausbildung Fachinformatiker: Anwendungsentwicklung, Ausbildung Fachinformatiker: Anwendungsentwicklung at Industrieschule Chemitz
Github Skills (80)
python10
go-language10
testing10
language-server-protocol10
security10
procedures10
build-automation10
encoding10
rpl10
webserver10
cpp10
concurrency10
p2p10
trie10
linux10
Programming languages (22)
Github contributions (5)
ethereum/hive
Sep 2020 - Jan 2023
Ethereum end-to-end test harness
Role in this project:
Back-end & DevOps Engineer
Back-end & DevOps EngineerContributions:94 reviews, 665 commits, 467 PRs in 2 years 4 months
Contributions summary:Felix made significant contributions to the `ethereum/hive` repository, primarily focused on improving the client integration for Ethereum tests. Their work included fixing build and startup scripts for the Trinity client, making consensus tests work, and adding support for setting log levels for OpenEthereum. Additionally, the user streamlined chain configurations for Nethermind and Openethereum, and contributed to the simulator infrastructure for testing and development. The user has demonstrated expertise in automating client integration and developing supporting tools.
golangend-to-endtest-harnessethereumtesting
ethereum/go-ethereum
Oct 2014 - Jan 2023
Go implementation of the Ethereum protocol
Role in this project:Back-end Developer
Back-end DeveloperContributions:57 releases, 1081 reviews, 1466 commits in 8 years 5 months
Contributions summary:Felix's commits focus on refactoring the RPC client for blockchain interaction, including implementing support for EIP-695 (eth_chainId), and fixing potential issues with the RPC websocket and HTTP transports. The primary focus of the changes appears to be on strengthening core transaction processing and ensuring robustness in client-server communication, as demonstrated by the refactoring of the HTTP request size limit, re-architecting the subscription management to prevent hang scenarios, and adding handling for various types of transactions. Their contribution also involves refining the code, such as cleaning up and streamlining the source code of internal ethapi and rpc.
golanggethethereump2pblockchain
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