KeYProject/key
Aug 2024 – Jan 2026
9 Months active
Languages Used
JavaJavaScriptJMLANTLRGradleJava PropertiesKey
Technical Skills
JavaSoftware ValidationStatic AnalysisBackend DevelopmentCode CleanupCode Formatting
Mattias Ulbrich
PROFILE
Mattias Ulbrich
Over nine months, Ulbrich contributed to the KeYProject/key repository by developing and refining core verification features, backend infrastructure, and editor tooling. He implemented static analysis and formal verification techniques in Java and JML to enforce immutability, improve final field handling, and enhance proof reliability. His work included building a flexible code highlighting framework, upgrading the Translator API for better model-method support, and refining the Boyer-Moore verification example for clarity and maintainability. Through code refactoring, documentation improvements, and expanded test coverage, Ulbrich consistently addressed correctness, maintainability, and reliability, demonstrating depth in backend development, static analysis, and formal methods.
Overall Statistics
Feature vs Bugs
68%Features
Repository Contributions
60Total
Bugs
11
Commits
60
Features
23
Lines of code
31,763
Activity Months9
Your Network
53 people
Work History
January 2026
3 Commits • 2 Features
Jan 1, 2026January 2026 (KeYProject/key): Delivered core correctness improvements and code hygiene enhancements focused on improving reliability and maintainability. Key outcomes include activation of a dormant null-handling rule and refinement of the LCP method's ensures clauses to deliver more predictable behavior, plus a clarifying update to example specifications. A code-quality cleanup removed trailing whitespace to improve readability and consistency across the codebase. Overall, these changes reduce null-handling risk, improve determinism in core logic, and streamline future maintenance, delivering tangible business value through more reliable software and faster onboarding for new engineers.
3 Commits • 2 Features
Jan 1, 2026January 2026 (KeYProject/key): Delivered core correctness improvements and code hygiene enhancements focused on improving reliability and maintainability. Key outcomes include activation of a dormant null-handling rule and refinement of the LCP method's ensures clauses to deliver more predictable behavior, plus a clarifying update to example specifications. A code-quality cleanup removed trailing whitespace to improve readability and consistency across the codebase. Overall, these changes reduce null-handling risk, improve determinism in core logic, and streamline future maintenance, delivering tangible business value through more reliable software and faster onboarding for new engineers.
January 2026
September 2025
7 Commits
Sep 1, 2025September 2025 (2025-09) highlights a set of reliability and quality improvements in KeYProject/key, focusing on datatype handling, taclet generation, JML term handling, and code readability. Key deliverables include fixes to datatype handling and taclet generation reliability, the JML boolean term handling fix with an ensureTerm helper, readability/correctness improvements in FunctionPredicateBuilder and TacletBuilder, and documentation cleanup in ParsingFacade. A test was added to cover datatype handling for non-recursive constructors to prevent regressions. These efforts reduce user-facing errors, improve proof reliability, and enhance maintainability, enabling faster iteration and clearer collaboration. Technologies demonstrated include Java, JML, unit testing, and code quality tooling, as well as improvements to naming/display conventions for taclets and datatype identifiers.
September 2025
7 Commits
Sep 1, 2025September 2025 (2025-09) highlights a set of reliability and quality improvements in KeYProject/key, focusing on datatype handling, taclet generation, JML term handling, and code readability. Key deliverables include fixes to datatype handling and taclet generation reliability, the JML boolean term handling fix with an ensureTerm helper, readability/correctness improvements in FunctionPredicateBuilder and TacletBuilder, and documentation cleanup in ParsingFacade. A test was added to cover datatype handling for non-recursive constructors to prevent regressions. These efforts reduce user-facing errors, improve proof reliability, and enhance maintainability, enabling faster iteration and clearer collaboration. Technologies demonstrated include Java, JML, unit testing, and code quality tooling, as well as improvements to naming/display conventions for taclets and datatype identifiers.
August 2025
2 Commits • 2 Features
Aug 1, 2025August 2025 — KeYProject/key: Delivered two major features with alignment to master and improved API consistency. Translator API upgraded to JTerm within the ncore framework, enabling better model-method support and type consistency. Updated Boyer-Moore formal verification example to align with the latest master (including Key project context), with refinements to proof obligations and JML files for correctness and maintainability. No major bugs fixed this month; minor issues addressed within the commits. Overall impact includes improved maintainability, reliability, and reduced future merge risk. Technologies demonstrated include JTerm, ncore, formal verification, JML, and repository alignment.
2 Commits • 2 Features
Aug 1, 2025August 2025 — KeYProject/key: Delivered two major features with alignment to master and improved API consistency. Translator API upgraded to JTerm within the ncore framework, enabling better model-method support and type consistency. Updated Boyer-Moore formal verification example to align with the latest master (including Key project context), with refinements to proof obligations and JML files for correctness and maintainability. No major bugs fixed this month; minor issues addressed within the commits. Overall impact includes improved maintainability, reliability, and reduced future merge risk. Technologies demonstrated include JTerm, ncore, formal verification, JML, and repository alignment.
August 2025
May 2025
1 Commits • 1 Features
May 1, 2025May 2025 — KeYProject/key: Delivered refinement to the Boyer-Moore formal verification example, improving modeling accuracy and verification efficiency. The work updates the example to use statements within model methods, refactors proof obligation settings, and introduces rule applications and simplifications to enhance clarity and maintainability of the verification code. The changes align verification steps with the updated model and prepare the codebase for future rule-driven optimizations.
May 2025
1 Commits • 1 Features
May 1, 2025May 2025 — KeYProject/key: Delivered refinement to the Boyer-Moore formal verification example, improving modeling accuracy and verification efficiency. The work updates the example to use statements within model methods, refactors proof obligation settings, and introduces rule applications and simplifications to enhance clarity and maintainability of the verification code. The changes align verification steps with the updated model and prepare the codebase for future rule-driven optimizations.
March 2025
7 Commits • 3 Features
Mar 1, 2025March 2025 performance summary for KeYProject/key: Delivered significant features, stability improvements, and refactoring that enhance correctness, error diagnostics, and maintainability. Key outcomes include robust final-field validation, syntax checks for model methods, improved lexical grammar for implicit identifiers, and streamlined sort handling through direct Sort usage. These changes reduce runtime risk, accelerate debugging, and support more reliable proofs in the Java-based proof system.
7 Commits • 3 Features
Mar 1, 2025March 2025 performance summary for KeYProject/key: Delivered significant features, stability improvements, and refactoring that enhance correctness, error diagnostics, and maintainability. Key outcomes include robust final-field validation, syntax checks for model methods, improved lexical grammar for implicit identifiers, and streamlined sort handling through direct Sort usage. These changes reduce runtime risk, accelerate debugging, and support more reliable proofs in the Java-based proof system.
March 2025
February 2025
22 Commits • 10 Features
Feb 1, 2025February 2025 monthly summary for KeYProject/key focusing on delivering correctness, reliability, and maintainability improvements. The team advanced core verification capabilities, expanded test coverage, and improved tooling readability, aligning with business value in model checking and specification processing.
February 2025
22 Commits • 10 Features
Feb 1, 2025February 2025 monthly summary for KeYProject/key focusing on delivering correctness, reliability, and maintainability improvements. The team advanced core verification capabilities, expanded test coverage, and improved tooling readability, aligning with business value in model checking and specification processing.
January 2025
4 Commits • 3 Features
Jan 1, 2025January 2025 performance summary for KeYProject/key. Delivered substantial backend and editor improvements across highlighting, verification, and editor UX, enhancing maintainability, correctness, and development velocity. Key outcomes include a flexible code highlighting framework, editor color customization, a confluence fix for boolean select operations, and extended support for static final fields in verification.
4 Commits • 3 Features
Jan 1, 2025January 2025 performance summary for KeYProject/key. Delivered substantial backend and editor improvements across highlighting, verification, and editor UX, enhancing maintainability, correctness, and development velocity. Key outcomes include a flexible code highlighting framework, editor color customization, a confluence fix for boolean select operations, and extended support for static final fields in verification.
January 2025
December 2024
13 Commits • 1 Features
Dec 1, 2024December 2024 performance summary for KeYProject/key focusing on delivering high-impact features, stabilizing automation workflows, and maintaining code quality. The work emphasized business value by strengthening correctness guarantees, improving automated proof and verification processes, and reducing maintenance risk across the repository.
December 2024
13 Commits • 1 Features
Dec 1, 2024December 2024 performance summary for KeYProject/key focusing on delivering high-impact features, stabilizing automation workflows, and maintaining code quality. The work emphasized business value by strengthening correctness guarantees, improving automated proof and verification processes, and reducing maintenance risk across the repository.
August 2024
1 Commits • 1 Features
Aug 1, 2024KeYProject/key — August 2024 monthly summary: Focused on delivering immutability safety improvements through static analysis. Implemented static analysis for final fields in constructors and added validation logic to enforce immutability of final fields, reducing risk of incorrect initialization and unintended mutations. This work strengthens code safety, correctness, and maintainability across the codebase.
1 Commits • 1 Features
Aug 1, 2024KeYProject/key — August 2024 monthly summary: Focused on delivering immutability safety improvements through static analysis. Implemented static analysis for final fields in constructors and added validation logic to enforce immutability of final fields, reducing risk of incorrect initialization and unintended mutations. This work strengthens code safety, correctness, and maintainability across the codebase.
August 2024
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Quality Metrics
Correctness87.6%
Maintainability85.8%
Architecture81.8%
Performance75.4%
AI Usage20.0%
Skills & Technologies
Programming Languages
ANTLRGradleJMLJavaJava PropertiesJavaScriptKey
Technical Skills
Algorithm ImplementationBackend DevelopmentBuild System ConfigurationCode AnalysisCode CleanupCode DocumentationCode FormattingCode HighlightingCode MaintenanceCode RefactoringCode ValidationCompiler DesignCompiler DevelopmentConfiguration ManagementCore Java
Repositories Contributed To
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