qiboteam/qibo
Feb 2025 – Feb 2026
9 Months active
Languages Used
PythonC++RSTTOMLreStructuredText
Technical Skills
Algorithm ImplementationBackend DevelopmentCircuit ManipulationCode LintingError MitigationGate Implementation
Alejandro Sopena
PROFILE
Alejandro Sopena
Alex Sopena contributed to the qiboteam/qibo repository, building and optimizing quantum circuit simulation features with a focus on backend development and error mitigation. Over nine months, Alex delivered new gate implementations, enhanced circuit representations, and improved performance through vectorization and caching strategies. Using Python and NumPy, Alex refactored core algorithms for reliability, expanded test coverage, and streamlined code quality with linting and documentation updates. The work addressed numerical stability in GPU paths, enabled flexible observable modeling, and reduced technical debt. Alex’s engineering demonstrated depth in quantum computing, numerical methods, and software testing, resulting in a robust, maintainable simulation platform.
Overall Statistics
Feature vs Bugs
64%Features
Repository Contributions
80Total
Bugs
13
Commits
80
Features
23
Lines of code
6,064
Activity Months9
Your Network
19 peopleWork History
February 2026
1 Commits
Feb 1, 2026February 2026 monthly summary for qiboteam/qibo. Focused on stabilizing GPU tests by clarifying Hamiltonian input types and ensuring explicit float conversion. The change addresses GPU test instability and improves numerical correctness in GPU computations, reducing flaky tests and increasing reliability of GPU-accelerated simulations.
1 Commits
Feb 1, 2026February 2026 monthly summary for qiboteam/qibo. Focused on stabilizing GPU tests by clarifying Hamiltonian input types and ensuring explicit float conversion. The change addresses GPU test instability and improves numerical correctness in GPU computations, reducing flaky tests and increasing reliability of GPU-accelerated simulations.
February 2026
December 2025
4 Commits • 2 Features
Dec 1, 2025Monthly work summary for 2025-12 focusing on key accomplishments for qiboteam/qibo: - Key features delivered: 1) Quantum backend: added support for a constant parameter in expectation value calculations, enabling constant terms in observables for more accurate quantum simulations. This expands backend functionality and improves modeling flexibility for quantum experiments. Commit: c44718053dcd43731b49ef20012b396184515769. 2) GeneralizedRBS gate: introduced dynamic qubit mapping via on_qubits, increasing circuit design flexibility; included whitespace cleanup and added tests to ensure correct behavior of the GeneralizedRBS gate in quantum circuits. Commits: 6cf813249726401859cdb1fc9683edfd814e9e44 (custom on_qubits method), 8742e6696763ad6c81ab6450921dd058842dac85 (remove space), 28e129146f1037b82ab7fdb480287c990a75289a (fix coverage). - Major bugs fixed: - While not listed as explicit bugs, the GeneralizedRBS enhancements included targeted fixes to ensure correct mapping, whitespace normalization, and improved test coverage, reducing edge-case failures in circuit construction and evaluation. - Technologies/skills demonstrated: - Quantum computing concepts: expectation value formulations, observable construction, and fixed-parameter handling. - Software engineering: feature development with clean code practices, whitespace cleanup, and test-driven enhancements. - Quality assurance: increased test coverage, reliability improvements, and maintainability across the qibo codebase. - Overall impact and business value: - The backend now supports constant terms in expectation values, enabling more versatile and accurate quantum simulations used in research and potential customer workflows. - Flexible qubit mapping for GeneralizedRBS improves circuit design efficiency and adaptability to varied hardware constraints. - Improved test coverage and code cleanliness reduce future maintenance costs and lower risk of regressions in critical quantum functionality. - Technologies/skills demonstrated in the month: - Python development, testing strategies (unit/integration tests), git-based collaboration, and commit hygiene. Overall, December 2025 delivered meaningful enhancements to core quantum computation capabilities, improved reliability, and reinforced maintainability for continued development.
December 2025
4 Commits • 2 Features
Dec 1, 2025Monthly work summary for 2025-12 focusing on key accomplishments for qiboteam/qibo: - Key features delivered: 1) Quantum backend: added support for a constant parameter in expectation value calculations, enabling constant terms in observables for more accurate quantum simulations. This expands backend functionality and improves modeling flexibility for quantum experiments. Commit: c44718053dcd43731b49ef20012b396184515769. 2) GeneralizedRBS gate: introduced dynamic qubit mapping via on_qubits, increasing circuit design flexibility; included whitespace cleanup and added tests to ensure correct behavior of the GeneralizedRBS gate in quantum circuits. Commits: 6cf813249726401859cdb1fc9683edfd814e9e44 (custom on_qubits method), 8742e6696763ad6c81ab6450921dd058842dac85 (remove space), 28e129146f1037b82ab7fdb480287c990a75289a (fix coverage). - Major bugs fixed: - While not listed as explicit bugs, the GeneralizedRBS enhancements included targeted fixes to ensure correct mapping, whitespace normalization, and improved test coverage, reducing edge-case failures in circuit construction and evaluation. - Technologies/skills demonstrated: - Quantum computing concepts: expectation value formulations, observable construction, and fixed-parameter handling. - Software engineering: feature development with clean code practices, whitespace cleanup, and test-driven enhancements. - Quality assurance: increased test coverage, reliability improvements, and maintainability across the qibo codebase. - Overall impact and business value: - The backend now supports constant terms in expectation values, enabling more versatile and accurate quantum simulations used in research and potential customer workflows. - Flexible qubit mapping for GeneralizedRBS improves circuit design efficiency and adaptability to varied hardware constraints. - Improved test coverage and code cleanliness reduce future maintenance costs and lower risk of regressions in critical quantum functionality. - Technologies/skills demonstrated in the month: - Python development, testing strategies (unit/integration tests), git-based collaboration, and commit hygiene. Overall, December 2025 delivered meaningful enhancements to core quantum computation capabilities, improved reliability, and reinforced maintainability for continued development.
September 2025
2 Commits • 1 Features
Sep 1, 2025Month: 2025-09 — Focused on performance, reliability, and maintainability of the Clifford backend in qiboteam/qibo. Delivered targeted backend optimizations, caching for Pauli generators, and cleaner phase vector handling. Refactored error mitigation observables using functional patterns for conciseness. Fixed a backend initialization typo and standardized naming across the module. Implemented via two code-review-driven commits, reinforcing code quality and consistency across the repository.
2 Commits • 1 Features
Sep 1, 2025Month: 2025-09 — Focused on performance, reliability, and maintainability of the Clifford backend in qiboteam/qibo. Delivered targeted backend optimizations, caching for Pauli generators, and cleaner phase vector handling. Refactored error mitigation observables using functional patterns for conciseness. Fixed a backend initialization typo and standardized naming across the module. Implemented via two code-review-driven commits, reinforcing code quality and consistency across the repository.
September 2025
August 2025
21 Commits • 8 Features
Aug 1, 2025Month 2025-08 Monthly Summary for qibo. This period focused on expanding gate expressivity, improving circuit representations, boosting performance, and hardening testing and reliability to accelerate delivery and increase confidence in simulations. Key features delivered: - GPI2 gate and Unitary Clifford gate support enabling larger, more versatile quantum circuits (commits: dde4e40e375c49b2cbb269283fdb8bf2f80569f3; 57b94189f426a6646f98265c623826bc6aa79c27). - Dehaene-De Moor representation implemented for compact circuit modeling (commit: ac7719996338a239bcbfda31b54b26f2ce2ec567). - Efficient sensitive circuit computations to improve runtime and scalability (commit: 7470a849748dcfde26d82713fc8eb5ce9af6c4ca). - Performance optimization: remove redundant data copy during execution to increase throughput (commit: 6b18585d70ba4fc30a8802316993bb5686d3f9bf). - Code quality and CI improvements: lint fixes and removal of debug prints (commits: a0c2042026b93016dadfe39a19bb35633ae7ac60; a34e0d6138d4622f53610c5040ef388a13879718). - Testing and coverage enhancements including GPU tests and updates to reflect current behavior (commits: 95f370010cc6c8d900d61ee02735374b6b289710; 313f836b3e7139446d9b43d6b4a258cdf2e8e0c0; 26233fc9700d7d828b9d65ab88202809f45a4eef; 5696e8daa2068e1ea45fbe928e6048b91d7c0878; c5562b8d32932d9b9cde01898a17b7de6ee910fc; 3d779e2cfe5357fa02191adaeaf58122ce3a3142; 90721fecd1efdf427abdfa3f96b1cc22fdf6e504). Major bugs fixed: - Quadratic correction fix (commit: 783895c5260af1db2da10be3d7309a42b5af6626). - Correct handling of measurements at the end of circuits (commit: a498354f7c2d91a38b2bc00d64128d55ee07ca54). - Explicit NotImplementedError to handle collapsing measurements not supported (commit: 34efbab4787cf2fbe1101cd1eab8c43ea6635fb1). - Handling of expectation values without samples in error mitigation (commit: 214d83106964aae13ea460e30f8ce0af5581bf64). - Fixes for backend usage and correctness (commits: ba401d844cc396b7b037a4505784ab31bf8e6932; 290a9ef3d022953f05f2d5cbda7fc5b8acbf3ee9). Overall impact and accomplishments: - Faster, more reliable simulations with expanded gate set and robust circuit representations. - Improved performance and reduced memory overhead across execution paths. - Stronger quality gates for CI, tests, and coverage, enabling safer releases and easier contributor onboarding. - Flexible backend options for error-sensitive workflows and improved error mitigation handling. Technologies/skills demonstrated: - Gate-level programming, unitary Clifford gates, and Dehaene-De Moor representation. - Performance optimization, memory management, and GPU-enabled testing. - Code quality discipline: linting, removal of prints, and comprehensive test suites. - Backend architecture and error mitigation strategies.
August 2025
21 Commits • 8 Features
Aug 1, 2025Month 2025-08 Monthly Summary for qibo. This period focused on expanding gate expressivity, improving circuit representations, boosting performance, and hardening testing and reliability to accelerate delivery and increase confidence in simulations. Key features delivered: - GPI2 gate and Unitary Clifford gate support enabling larger, more versatile quantum circuits (commits: dde4e40e375c49b2cbb269283fdb8bf2f80569f3; 57b94189f426a6646f98265c623826bc6aa79c27). - Dehaene-De Moor representation implemented for compact circuit modeling (commit: ac7719996338a239bcbfda31b54b26f2ce2ec567). - Efficient sensitive circuit computations to improve runtime and scalability (commit: 7470a849748dcfde26d82713fc8eb5ce9af6c4ca). - Performance optimization: remove redundant data copy during execution to increase throughput (commit: 6b18585d70ba4fc30a8802316993bb5686d3f9bf). - Code quality and CI improvements: lint fixes and removal of debug prints (commits: a0c2042026b93016dadfe39a19bb35633ae7ac60; a34e0d6138d4622f53610c5040ef388a13879718). - Testing and coverage enhancements including GPU tests and updates to reflect current behavior (commits: 95f370010cc6c8d900d61ee02735374b6b289710; 313f836b3e7139446d9b43d6b4a258cdf2e8e0c0; 26233fc9700d7d828b9d65ab88202809f45a4eef; 5696e8daa2068e1ea45fbe928e6048b91d7c0878; c5562b8d32932d9b9cde01898a17b7de6ee910fc; 3d779e2cfe5357fa02191adaeaf58122ce3a3142; 90721fecd1efdf427abdfa3f96b1cc22fdf6e504). Major bugs fixed: - Quadratic correction fix (commit: 783895c5260af1db2da10be3d7309a42b5af6626). - Correct handling of measurements at the end of circuits (commit: a498354f7c2d91a38b2bc00d64128d55ee07ca54). - Explicit NotImplementedError to handle collapsing measurements not supported (commit: 34efbab4787cf2fbe1101cd1eab8c43ea6635fb1). - Handling of expectation values without samples in error mitigation (commit: 214d83106964aae13ea460e30f8ce0af5581bf64). - Fixes for backend usage and correctness (commits: ba401d844cc396b7b037a4505784ab31bf8e6932; 290a9ef3d022953f05f2d5cbda7fc5b8acbf3ee9). Overall impact and accomplishments: - Faster, more reliable simulations with expanded gate set and robust circuit representations. - Improved performance and reduced memory overhead across execution paths. - Stronger quality gates for CI, tests, and coverage, enabling safer releases and easier contributor onboarding. - Flexible backend options for error-sensitive workflows and improved error mitigation handling. Technologies/skills demonstrated: - Gate-level programming, unitary Clifford gates, and Dehaene-De Moor representation. - Performance optimization, memory management, and GPU-enabled testing. - Code quality discipline: linting, removal of prints, and comprehensive test suites. - Backend architecture and error mitigation strategies.
June 2025
1 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for qiboteam/qibo: Focused on documentation improvements to boost discoverability of new state generation APIs. Delivered clear references and usage guidance for dicke_state and graph_state in qibo docs, linked from API references, with a traceable commit. No major bugs fixed. Result: faster onboarding for new users, better API visibility, and higher-quality documentation in qiboteam/qibo. Technologies/skills demonstrated include technical writing, API documentation, cross-referencing, version control, and collaboration.
1 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for qiboteam/qibo: Focused on documentation improvements to boost discoverability of new state generation APIs. Delivered clear references and usage guidance for dicke_state and graph_state in qibo docs, linked from API references, with a traceable commit. No major bugs fixed. Result: faster onboarding for new users, better API visibility, and higher-quality documentation in qiboteam/qibo. Technologies/skills demonstrated include technical writing, API documentation, cross-referencing, version control, and collaboration.
June 2025
May 2025
3 Commits • 1 Features
May 1, 2025May 2025: Delivered usability and documentation enhancements for HammingWeightBackend in qibo, improving user guidance for executing circuits with a specified Hamming weight, refining HammingWeightResult initialization, and cleaning up outdated API examples. Strengthened test reliability by running tests with an explicit numpy backend and incorporated feedback to improve documentation and API references. Result: clearer onboarding, more reliable tests, and maintainable codebase with enhanced API confidence.
May 2025
3 Commits • 1 Features
May 1, 2025May 2025: Delivered usability and documentation enhancements for HammingWeightBackend in qibo, improving user guidance for executing circuits with a specified Hamming weight, refining HammingWeightResult initialization, and cleaning up outdated API examples. Strengthened test reliability by running tests with an explicit numpy backend and incorporated feedback to improve documentation and API references. Result: clearer onboarding, more reliable tests, and maintainable codebase with enhanced API confidence.
April 2025
10 Commits • 2 Features
Apr 1, 2025April 2025: Focused on performance gains for the HammingWeight backend and improving developer experience through code quality and tooling enhancements. Delivered vectorized operations and architecture refinements that enable faster, scalable weight-based computations, along with dynamic backend inheritance and centralized backend construction. Completed linting cleanups, explicit coverage directives, and build/config cleanup to improve maintainability and test reliability. Overall impact: higher performance, reduced technical debt, and smoother release readiness; demonstrated strong collaboration and problem-solving across backend architecture and tooling.
10 Commits • 2 Features
Apr 1, 2025April 2025: Focused on performance gains for the HammingWeight backend and improving developer experience through code quality and tooling enhancements. Delivered vectorized operations and architecture refinements that enable faster, scalable weight-based computations, along with dynamic backend inheritance and centralized backend construction. Completed linting cleanups, explicit coverage directives, and build/config cleanup to improve maintainability and test reliability. Overall impact: higher performance, reduced technical debt, and smoother release readiness; demonstrated strong collaboration and problem-solving across backend architecture and tooling.
April 2025
March 2025
30 Commits • 6 Features
Mar 1, 2025March 2025 performance sprint for qibo: delivered new math utilities, gate extensions, probability tooling, and strengthened test coverage with codebase stabilization and documentation updates.
March 2025
30 Commits • 6 Features
Mar 1, 2025March 2025 performance sprint for qibo: delivered new math utilities, gate extensions, probability tooling, and strengthened test coverage with codebase stabilization and documentation updates.
February 2025
8 Commits • 2 Features
Feb 1, 2025February 2025 progress on qibo focused on making error mitigation simpler and more scalable, while tightening correctness and test hygiene. Delivered a direct gate-based error mitigation workflow by removing random Clifford gates, corrected Y-gate Clifford attributes, expanded gate support to multi-qubit unitaries, and improved test stability and code style. These changes improve simulation accuracy, enable larger and more complex circuits, speed up development cycles, and strengthen CI reliability for ongoing product delivery.
8 Commits • 2 Features
Feb 1, 2025February 2025 progress on qibo focused on making error mitigation simpler and more scalable, while tightening correctness and test hygiene. Delivered a direct gate-based error mitigation workflow by removing random Clifford gates, corrected Y-gate Clifford attributes, expanded gate support to multi-qubit unitaries, and improved test stability and code style. These changes improve simulation accuracy, enable larger and more complex circuits, speed up development cycles, and strengthen CI reliability for ongoing product delivery.
February 2025
Activity
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Quality Metrics
Correctness87.8%
Maintainability84.8%
Architecture83.2%
Performance78.4%
AI Usage21.6%
Skills & Technologies
Programming Languages
C++PythonRSTTOMLreStructuredText
Technical Skills
Algorithm ImplementationAlgorithm OptimizationBackend DevelopmentCircuit ManipulationCircuit OptimizationCircuit SimulationCode CleanupCode CoverageCode Coverage OptimizationCode LintingCode QualityCode RefactoringConfiguration ManagementCuPyDebugging
Repositories Contributed To
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