
Harrison Cook engineered robust data processing and model training pipelines across the ECMWF Anemoi suite, focusing on scalable inference, dynamic configuration, and reliable I/O orchestration. Working in repositories such as ecmwf/anemoi-inference and ecmwf/anemoi-core, he implemented features like dynamic device selection, flexible output formats, and enhanced metadata handling using Python and PyTorch. His approach emphasized modularity, with refactored callback systems, improved error diagnostics, and automated documentation generation. By integrating technologies like YAML configuration, NetCDF, and Zarr, Harrison addressed deployment friction and data integrity, delivering maintainable solutions that improved hardware compatibility, reproducibility, and developer experience across evolving machine learning workflows.

October 2025 performance summary for core ECMWF projects. Focus this month was on packaging quality, robust I/O orchestration, and plotting correctness to improve reliability and business value. Delivered packaging improvements for PyPI visibility, standardized output handling across inferences, fixed NetCDF output shape issues, cleaned up configuration surfaces, and enhanced plotting metadata for more accurate visualizations. These changes reduce deployment friction, increase data integrity, and improve developer experience across multiple repositories.
October 2025 performance summary for core ECMWF projects. Focus this month was on packaging quality, robust I/O orchestration, and plotting correctness to improve reliability and business value. Delivered packaging improvements for PyPI visibility, standardized output handling across inferences, fixed NetCDF output shape issues, cleaned up configuration surfaces, and enhanced plotting metadata for more accurate visualizations. These changes reduce deployment friction, increase data integrity, and improve developer experience across multiple repositories.
September 2025 monthly summary covering core data processing and tooling across the ecmwf repositories (anemoi-inference, anemoi-utils, earthkit-data). Key deliverables include (1) Plot Output Configuration Documentation and YAML Options with updated docs, removal of outdated experimental warning, and a concrete YAML example (commit a16fe4218a15d38c7cfce9dd472eb96d97c7aa9d). (2) Fix for Cutout Input Handling in load_forcings_state to ensure variables parameter is handled correctly and cutout functionality is restored (commit 35c1cdbb694e9eb799b0e3ab4c1b37c69abe3ba9). (3) Metadata Get Command: JSON/YAML Output Flags with --json/--yaml support and dynamic formatting (commit 6af46c4e715fc55aca374d2112976aa7d1bac589). (4) GRIB Reader: Stream-based multi-message support enabling processing of multiple messages from a single memory buffer, plus refactor to GribStreamReader and associated tests and docs (commit 11c78bbcfb638dc5cfdd58f64bb2613ca595cb98). Overall impact includes improved documentation accessibility, restored functional correctness for cutouts, enhanced automation through flexible metadata outputs, and scalable in-memory GRIB processing. Technologies/skills demonstrated include Python-based tooling, YAML/JSON handling, memory-buffer processing with GribStreamReader, documentation and test-driven development.
September 2025 monthly summary covering core data processing and tooling across the ecmwf repositories (anemoi-inference, anemoi-utils, earthkit-data). Key deliverables include (1) Plot Output Configuration Documentation and YAML Options with updated docs, removal of outdated experimental warning, and a concrete YAML example (commit a16fe4218a15d38c7cfce9dd472eb96d97c7aa9d). (2) Fix for Cutout Input Handling in load_forcings_state to ensure variables parameter is handled correctly and cutout functionality is restored (commit 35c1cdbb694e9eb799b0e3ab4c1b37c69abe3ba9). (3) Metadata Get Command: JSON/YAML Output Flags with --json/--yaml support and dynamic formatting (commit 6af46c4e715fc55aca374d2112976aa7d1bac589). (4) GRIB Reader: Stream-based multi-message support enabling processing of multiple messages from a single memory buffer, plus refactor to GribStreamReader and associated tests and docs (commit 11c78bbcfb638dc5cfdd58f64bb2613ca595cb98). Overall impact includes improved documentation accessibility, restored functional correctness for cutouts, enhanced automation through flexible metadata outputs, and scalable in-memory GRIB processing. Technologies/skills demonstrated include Python-based tooling, YAML/JSON handling, memory-buffer processing with GribStreamReader, documentation and test-driven development.
August 2025 monthly summary focusing on cross-repo delivery and business value across the Anemoi stack. Delivered key features and robustness improvements in inference, core training components, and utilities, enabling easier deployment, better hardware utilization, and more reliable training workflows. Overall impact includes improved hardware compatibility, clearer error visibility, richer plotting capabilities, and more flexible APIs for downstream integration.
August 2025 monthly summary focusing on cross-repo delivery and business value across the Anemoi stack. Delivered key features and robustness improvements in inference, core training components, and utilities, enabling easier deployment, better hardware utilization, and more reliable training workflows. Overall impact includes improved hardware compatibility, clearer error visibility, richer plotting capabilities, and more flexible APIs for downstream integration.
Month: 2025-07 — The team delivered a set of reliability-focused features and robustness improvements across four repositories, with clear business value in data interoperability, pipeline reliability, and developer UX. Work emphasized forward-compatibility with evolving libraries, improved data I/O options, and stronger input validation for automated workflows.
Month: 2025-07 — The team delivered a set of reliability-focused features and robustness improvements across four repositories, with clear business value in data interoperability, pipeline reliability, and developer UX. Work emphasized forward-compatibility with evolving libraries, improved data I/O options, and stronger input validation for automated workflows.
June 2025: Delivered key features for scalable inference and model composition, improved provenance tracking and reproducibility, and updated documentation to support teams and users. Highlights include nested model support in MarsInput and Cutout, dynamic supporting arrays in the external graph runner, a provenance git state validation fix, a variable grouping refactor with parameter recognition bug fix, and an updated AnemoI docs URL. These changes reduce external data dependencies, strengthen model composition reliability, and enhance developer experience and collaboration.
June 2025: Delivered key features for scalable inference and model composition, improved provenance tracking and reproducibility, and updated documentation to support teams and users. Highlights include nested model support in MarsInput and Cutout, dynamic supporting arrays in the external graph runner, a provenance git state validation fix, a variable grouping refactor with parameter recognition bug fix, and an updated AnemoI docs URL. These changes reduce external data dependencies, strengthen model composition reliability, and enhance developer experience and collaboration.
May 2025: Delivered targeted features and bug fixes across four repositories, improving metadata management, model training stability, and developer tooling. Notable outcomes include a new UserMetadata override/clone API with tests, VS Code-based metadata editing, a fix for correct device placement of the scaler in loss computation, explicit batch normalization for loss invariance, and a new Variable level-type classification extension.
May 2025: Delivered targeted features and bug fixes across four repositories, improving metadata management, model training stability, and developer tooling. Notable outcomes include a new UserMetadata override/clone API with tests, VS Code-based metadata editing, a fix for correct device placement of the scaler in loss computation, explicit batch normalization for loss invariance, and a new Variable level-type classification extension.
April 2025: Delivered targeted reliability improvements across inference testing and dataset loading, with a strong emphasis on test infrastructure and error diagnostics. These changes reduce flaky tests, improve load-time validation, and stabilize data preparation, enabling faster bug isolation and more confident deployments across model inference pipelines.
April 2025: Delivered targeted reliability improvements across inference testing and dataset loading, with a strong emphasis on test infrastructure and error diagnostics. These changes reduce flaky tests, improve load-time validation, and stabilize data preparation, enabling faster bug isolation and more confident deployments across model inference pipelines.
March 2025 performance summary for the Anemoi suite focused on expanding accessibility, improving data integrity, and strengthening automation and documentation across repositories. Key progress included feature introductions and quality improvements in inference, robust CI and repository hygiene, and targeted documentation efforts, with a disciplined approach to experimentation in core scheduling features.
March 2025 performance summary for the Anemoi suite focused on expanding accessibility, improving data integrity, and strengthening automation and documentation across repositories. Key progress included feature introductions and quality improvements in inference, robust CI and repository hygiene, and targeted documentation efforts, with a disciplined approach to experimentation in core scheduling features.
February 2025: Delivered core training and inference enhancements across ecmwf/anemoi-core, ecmwf/reusable-workflows, and ecmwf/anemoi-inference, focusing on business value, reliability, and developer experience. Key features include training control enhancements (TimeLimit callback and EarlyStopping wrapper) with last-checkpoint logging for easy resumption, flexible loss composition (per-loss scalars in CombinedLoss), and schema/documentation improvements. Workflow improvements added clearer PR templates and integrated pre-commit-docconvert to improve documentation quality. Inference tooling gained TruthOutput for historical forecast evaluation and CLI validate command documentation. Major bug fix: rework of CombinedLoss to support per-loss scalars, increasing stability and configurability. Overall impact: more reliable, tunable model training, robust documentation and schema standards, streamlined contributor workflows, and enhanced historical forecast evaluation. Technologies/skills demonstrated: PyTorch Lightning, custom callbacks, loss composition, schema/docs (Sphinx), pre-commit tooling, and CLI documentation."
February 2025: Delivered core training and inference enhancements across ecmwf/anemoi-core, ecmwf/reusable-workflows, and ecmwf/anemoi-inference, focusing on business value, reliability, and developer experience. Key features include training control enhancements (TimeLimit callback and EarlyStopping wrapper) with last-checkpoint logging for easy resumption, flexible loss composition (per-loss scalars in CombinedLoss), and schema/documentation improvements. Workflow improvements added clearer PR templates and integrated pre-commit-docconvert to improve documentation quality. Inference tooling gained TruthOutput for historical forecast evaluation and CLI validate command documentation. Major bug fix: rework of CombinedLoss to support per-loss scalars, increasing stability and configurability. Overall impact: more reliable, tunable model training, robust documentation and schema standards, streamlined contributor workflows, and enhanced historical forecast evaluation. Technologies/skills demonstrated: PyTorch Lightning, custom callbacks, loss composition, schema/docs (Sphinx), pre-commit tooling, and CLI documentation."
January 2025 monthly performance summary highlighting cross-repo delivery of data IO enhancements, CI/documentation improvements, and release hygiene, with a notable GPU-memory-related bug fix.
January 2025 monthly performance summary highlighting cross-repo delivery of data IO enhancements, CI/documentation improvements, and release hygiene, with a notable GPU-memory-related bug fix.
December 2024 performance summary focusing on reliability, usability, and model-inference enablement across three repositories. Key refactors centralized environment validation, model-loading integration was added through Hugging Face Hub, and metadata/metrics handling improvements enhanced observability and experiment reproducibility. Together, these changes reduce runtime errors, accelerate model deployment, and improve governance of inference pipelines.
December 2024 performance summary focusing on reliability, usability, and model-inference enablement across three repositories. Key refactors centralized environment validation, model-loading integration was added through Hugging Face Hub, and metadata/metrics handling improvements enhanced observability and experiment reproducibility. Together, these changes reduce runtime errors, accelerate model deployment, and improve governance of inference pipelines.
Month 2024-11 focused on delivering business value through release automation, clearer configuration, enhanced ML experimentation, and backend extensibility, while hardening inference pipelines and development environment governance. Key outcomes include streamlined release workflows via automated changelog generation, safer argument renaming for backward compatibility, clearer configuration naming in core, expanded MLflow logging, and new JAX backend support for EarthKit-Data. Also resolved critical runtime issues in training/inference pipelines and aligned development dependencies to ensure reproducible environments.
Month 2024-11 focused on delivering business value through release automation, clearer configuration, enhanced ML experimentation, and backend extensibility, while hardening inference pipelines and development environment governance. Key outcomes include streamlined release workflows via automated changelog generation, safer argument renaming for backward compatibility, clearer configuration naming in core, expanded MLflow logging, and new JAX backend support for EarthKit-Data. Also resolved critical runtime issues in training/inference pipelines and aligned development dependencies to ensure reproducible environments.
October 2024: Delivered stability and extensibility across the Anemoi suite, delivering concrete business value through reduced deployment risk, smoother CI, and enhanced training capabilities. Highlights include robust version loading to prevent ImportError, CI precommit stabilization, Python version compatibility guardrails, expanded loss functions and modular training components, and a refactored, more maintainable callback system plus clarified documentation.
October 2024: Delivered stability and extensibility across the Anemoi suite, delivering concrete business value through reduced deployment risk, smoother CI, and enhanced training capabilities. Highlights include robust version loading to prevent ImportError, CI precommit stabilization, Python version compatibility guardrails, expanded loss functions and modular training components, and a refactored, more maintainable callback system plus clarified documentation.
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