Štěpán Šindelář
Software Engineer at Oracle Labs
Prague, Czechia
Summary
🤩
Rockstar🎓
Top SchoolŠtěpán Šindelář is a software engineer with 14 years of experience focused on compilers, static program analysis, verification, development tools and middleware, currently based in Prague. As a long-term contributor and tech lead at Oracle Labs on GraalVM and its R runtime, he works on low-level runtime and compilation internals, including LLVM integration and high-performance language runtimes like GraalPy. His background includes commercial .NET and tooling work—building compilers, control/data-flow frameworks and IDE integrations—and an academic project implementing an SMP-capable OS for MIPS, reflecting deep systems knowledge. He combines high-level abstractions (ORMs, APIs) with hands-on expertise in algorithms, memory management and system calls. He prefers opportunities strictly in his specialty areas within the Czech Republic or Europe and is selective about outreach outside those domains. Opinions on his GitHub are his own, and his commits reveal a pragmatic focus on fixing integration and performance issues in widely used open-source VM projects.
14 years of coding experience
6 years of employment as a software developer
Master's degree, Dependable Systems, Master's degree, Dependable Systems at Charles University in Prague, Faculty of Mathematics and PhysicsComputer Science, Computer Science at Durham UniversityExchange student, Computer Science, Exchange student, Computer Science at Macquarie University
English, Czech
Github Skills (11)
javas10
python10
performance-optimization10
java10
llvm10
interpreter9
java-bytecode9
compiler-compiler9
compiler9
build-system8
code-optimization8
Programming languages (9)
Github contributions (5)
oracle/graalpython
Apr 2020 - Jan 2023
GraalPy – A high-performance embeddable Python 3 runtime for Java
Role in this project:
Back-end Developer
Back-end DeveloperContributions:5 reviews, 784 commits, 12 comments in 2 years 9 months
Contributions summary:Štěpán primarily focused on refactoring attribute writing for classes within the GraalPy project, a high-performance Python 3 runtime for Java. Their contributions involved modifying and refactoring Java code, specifically in WriteAttributeToObjectNode.java and FactorySSTVisitor.java files. These changes indicate a focus on improving the performance and functionality of attribute writing in the Python runtime.
pythongraal-nativejqpython-3graalvm
oracle/graal
Feb 2018 - Mar 2024
GraalVM compiles Java applications into native executables that start instantly, scale fast, and use fewer compute resources 🚀
Role in this project:Back-end Developer
Back-end DeveloperContributions:34 comments, 9 issues in 6 years 1 month
Contributions summary:Štěpán primarily worked on fixing linking issues and updating imports within the GraalVM project. The commits indicate the user made changes to Java source code related to compiler debugging and LLVM runtime, likely to address build and integration problems. The contributions focused on the internals of GraalVM compilation processes, including symbol initialization and overwrite operations.
polyglotpythonjavascriptrubyanywhere
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