Month: 2025-10 summary focusing on delivering business value through robust math/geometry refactors, stronger test coverage, and broader applicability of derived geometry. The work enhanced accuracy, regression reliability, and developer efficiency while expanding the library’s applicability to both tokamaks and mirrors via RZ coordinates.

September 2025 performance summary: In ammarhakim/gkylcas, completed Maxima Gyrokinetic Kernel File Refactor, renaming and removing outdated kernel maxima to improve code organization and long-term maintainability (commit d427ffa4e0a0bc19fe385b81b46abb393d3cb0f4). In ammarhakim/gkeyll, implemented critical fixes and enhancements: Jacobian usage updated for species heating to align with the updated geometry data structure (commit cf08e6228fbd11a1ba2b8f232c7b9192491e261f), enhanced EQDSK header parsing so geqdsk readers now automatically handle header comments and standardize labels (commit c2d8c56907afeb7c6922aff7790577d771cef348), corrected magnetic field magnitude in a unit test to use the Euclidean norm (commit de4d24414910d37bf47cfba2d2d9c4a93411dc7c), introduced code quality and documentation cleanup across tests and gyrokinetic geometry (multiple commits), and added support for 1x grids in m2n_surface population (commit 4e997b7379d5801fbab33599478f8fd681857073). Additionally, a memory optimization was implemented by conditional allocation of fghost_vol based on diffusion presence to reduce memory usage (commit db50ec877c2b94f5dfde93858fe8b10ca6e6763f). These changes improve reliability of physics calculations, streamline data formats, and reduce memory footprint in large-scale simulations.

August 2025 monthly summary for a developer team focusing on geometry, I/O, and GK/MB improvements across the gkeyll and gkylcas repositories. Delivered a robust input-file geometry API, enhanced FromFile I/O, expanded geometry generation capabilities, and introduced cost-saving domain reductions. Also stabilized physics outputs through regression fixes, test hygiene, and configuration fixes across GPU-accelerated geometry paths. Demonstrated strong collaboration across repos and a commitment to reliable, business-value-driven simulations.

July 2025 performance and stability month for ammarhakim/gkylcas and ammarhakim/gkeyll. Focused on GPU readiness, kernel-level performance, memory footprint reduction, and code quality improvements to enable larger, faster, and more reliable gyrokinetic simulations across CPU and GPU targets. Delivered substantial GPU kernel optimizations, nonuniform grid support, race-condition mitigation, and maintainability enhancements, with a clear path toward scalable, production-ready runs on multi-GPU clusters.

June 2025 monthly summary for ammarhakim's development work across gkeyll and gkylcas. Focused on delivering performance improvements and robust geometry handling for multi-dimensional tokamak simulations, while strengthening the kernel framework and ensuring alignment with the quadgeo baseline. Key wins include speedups in field-line tracing via cubic-root finding, DG geometry scaffolding, and a comprehensive DG geometry workflow for surface and volume representations. Major kernel and hook work, as well as targeted bug fixes, have improved stability and testability, enabling scalable 2x2v tokamak runs with drifts that are faster and more reliable.

May 2025 performance summary focusing on geometry kernel delivery, GK geometry modernization, and testing/instrumentation that improved accuracy, GPU readiness, and observability. Key features delivered include the interior-quadrature geometry kernel (calcDerivedGeo_quad) for interior node calculations, GK geometry refactor with separated surface/corner/interior structs and CUDA integration updates plus 1x deflation support, and 3D Ser/Quad base geometry improvements. Testing, timing, and IO enhancements added detailed timing instrumentation and improved regression/test coverage for mapc2p, wgrad, and wgrad2, with corresponding unit-test updates. Major bugs fixed include CUDA/geometry integration regressions and compilation issues encountered during refactoring, plus cleanup of legacy code, ensuring consistent behavior across single and multi-GPU runs. Overall impact: more accurate geometry computations, GPU-ready data structures, and a robust testing/observability framework that reduces risk and accelerates iteration. Technologies/skills demonstrated: CUDA/C++, advanced geometry representations, refactoring discipline, unit/regression testing, and performance instrumentation.

Concise monthly summary for 2025-04 focusing on business value and technical achievements for the ammarhakim/gkeyll project. Delivered enhancements to geometry handling and test coverage to accelerate validation, improve reliability, and reduce CI time. Implemented performance instrumentation to guide optimizations, and stabilized parallel communications paths with aligned serial/parallel tests.

March 2025 performance summary for ammarhakim/gkeyll focused on geometry fidelity, neutral-species handling, and scalability/testing. Key improvements enhance numerical accuracy, stability, cross-GPU reliability, and test coverage, translating to higher-fidelity simulations and faster iteration cycles.

February 2025: Focused on codebase quality, geometry fidelity, and test reliability across gkeyll and gkylcas. Key outcomes include naming standardization, BC-aligned test updates, geometry kernel enhancements, and reliability hardening against valgrind issues, contributing to more maintainable code, fewer CI flakies, and higher simulation fidelity near geometry-sensitive regions.

January 2025 monthly summary for ammarhakim/gkeyll. Focused on gyrokinetic (GK) physics integration, multi-app data flow, and robust geometry handling to improve stability, accuracy, and operator productivity for tokamak simulations. Delivered new GK boundary conditioning objects, end-to-end GK/Ne input propagation, and a global normalization workflow across multi-block (MB) geometry, along with synchronized solvers and 1D capabilities to enable more realistic and GPU-ready workflows. Supported by targeted bug fixes that improved stability and test reliability.

December 2024: Delivered targeted improvements in geometry metric computation, resource management, and array integration within the gkeyll project. The work enhanced numerical accuracy, reduced runtime, and improved maintainability, enabling broader applicability and future optimization.

Month: 2024-11. This period focused on delivering GPU-accelerated validation, stabilizing core deflated-field computations, and strengthening geometry tooling across gkeyll and gkylcas. Key outcomes include GPU-enabled tests for deflated array ops and allgather with automated value checks, stability fixes to rhoJ operations in gkfield, deflated multiplication support in multib field RH, post-Poisson phi smoothing in multib, and an X-point location check in tok-geo tracing. These workstreams improved reliability, cross-platform parity, and time-to-feedback for GPU and multi-block workflows, while maintaining compatibility with existing single-block apps and ensuring safer defaults for geometry calculation.

October 2024 monthly summary: Delivered critical numerical improvements and maintainability enhancements across two GKYL repositories (ammarhakim/gkylzero and ammarhakim/gkeyll). In gkylzero, fixed Jacobian handling in the Poisson-based field solver by applying the Jacobian before solving and incorporating it into the multib_field RHS, with tests updated to reflect the changes. In gkeyll, introduced M0 moment caching for improved charge density stability; corrected division by J for Boltzmann electron rho_c accumulation, and ensured correct array usage for 1D vs higher-D simulations. Also aligned boundary inputs for a 12-block regression test and standardized naming/documentation for the multib field object to _multibz, improving readability and maintainability. These changes collectively enhance numerical accuracy, stability, test reliability, and code maintainability, delivering clear business value in simulation accuracy and development velocity.