March 2026: CQCL/tket2 delivered a performance optimization by adding a squash_borrows flag to NormalizeGuppy, enabling squashing of return-borrow pairs on BorrowArrays and exposing the flag to Python for easier experimentation. This work enhances runtime efficiency of the optimization pipeline and positions us for further back-end performance gains.

Concise monthly summary for 2026-01 focused on CQCL/tket2 feature delivery and test coverage. Implemented a feature to prune exposure of public functions in LLVM output after linearization, reducing the LLVM IR surface area and preventing leakage of internal APIs. Updated QSystemPass to enforce private visibility and added tests to verify the behavior. The work improves encapsulation, safety of the emitted IR, and maintainability of the codebase.

Monthly summary for 2025-12 highlighting key business-value outcomes and technical achievements across two core repositories. Delivered a major circuit-representation optimization in CQCL/tket2 by replacing Subcircuit with SiblingSubgraph, improving rewrite efficiency and maintainability. Strengthened test coverage and resilience in CQCL/guppylang by adding a targeted Hugr BorrowArray test to guard against linking problems with different-length arrays, reducing regression risk. Overall, these efforts boost performance potential, reliability, and developer velocity, with direct impact on production readiness and downstream hardware mapping workloads.

Monthly work summary for CQCL/tket2 (2025-11): Delivered feature improvements to optimization testing, introduced an optimization pass to improve performance in arrays, and completed a code refactor for efficiency. No major bugs reported in this period. The work enhances reliability, performance, and maintainability, delivering concrete business value by speeding up compilation workflows and enabling more robust validation of optimizations.

October 2025 Monthly Summary for CQCL/guppylang: Delivered targeted correctness improvements and analysis enhancements to the Hugr pipeline, boosting compiler reliability and side-effect analysis accuracy. Implemented a critical bug fix for affine-bounded type variable compilation and delivered a significant enhancement to side-effect tracking across CFGs and conditionals. The work included refactors, documentation updates, and expanded test coverage, contributing to lower maintenance costs and faster integration of future features.

July 2025: Delivered a targeted feature and dependency upgrade in CQCL/tket2 to streamline data flow and reduce overhead in the Guppy extension. The key deliverable was introducing the LowerDropsPass in tket-qsystem and upgrading hugr to 0.22.1 to ensure compatibility with the new pass and minor version changes, enabling removal of Drop operations from the Guppy extension and improving overall QPU data handling.

December 2024: CQCL/guppylang delivered targeted improvements to floating-point testing in integration tests by introducing the run_float_fn_approx fixture (replacing the previous run_float_fn) and enabling pytest.approx-based comparisons with optional rel, abs, and nan_ok parameters. This change enhances precision, reduces flaky FP assertions, and supports safer FP-heavy refactors in CI pipelines.