October 2025 monthly performance summary focusing on delivering business value and strengthening technical foundations across four repos. Key features and fixes delivered: - opensafely-core/ehrql: Event-level data (ELD) permissions hardened and integrated into the generic permissions framework with explicit ELD grants; tests updated to reflect new permission claims. Commits include b8428cfc284a4b5635433c880558ecbe28be0479, 687190d935d608ad4e05c9c6faa189d772add3bb, and 5bf08e832bbe352fd13cdeca45853116c184c361. - opensafely-core/ehrql: Infrastructure, CI/CD, and code quality improvements (base image, Python 3.13 upgrade, signing and packaging fixes, typing and lint improvements, UTC time handling, and CI workflow updates). Representative commits: 022292a68ead91cde953ae14d4e365518d9088f2, 8e6a4f3f7490f9cb38ec8d31772188e25de5c677, 6abb41e2fa2dba65f2c034d5ca9b981c833f3c05, 4d34689951884cebb951153d9945f68596daca88, etc. - opensafely-core/job-runner: Database backup and recovery automation including a new management command for timestamped backups, a daily cron task, deployment prerequisites for backup volumes, and recovery documentation. Commits include 90eb085a426155215b48498988f16a18f40bf00c, bd13d0ca171b2e88bf3c00e50f546fbc45cdd3be, ea3ba3602e8aa6b6fd97f53c4462c7e08943cc3f, 0474f366312984375a7e5babaf426bc730471992. - bennettoxford/openprescribing: 500 error page user experience enhancement with friendlier messaging, ongoing-issues notice, and resilience when the main web process is down. Commit: 96b446fc5b4ef933835ef93343364dd4d0c64293. - opensafely-core/job-runner: CI stability improvements by removing macOS tests to reduce flakiness and simplify configuration. Commit: 35da31dfc83e88ed2b34c2c66d0e1edbff7b00d0. Overall impact: strengthened data governance and permissions, improved reliability and maintainability of CI/CD pipelines, introduced disaster recovery tooling, and delivered customer-facing UX improvements. Technologies and skills demonstrated include Python 3.13, advanced typing and linting, UTC time handling, Docker base image management, CI/CD workflow optimization, and robust test strategy across multiple repos.

September 2025: Delivered substantive improvements across ehrql and job-runner focused on governance, security, testing, observability, and documentation. Implemented metadata-driven table governance, strengthened permissions enforcement and documentation, enhanced testing tooling, added introspection capabilities, and refreshed docs. In job-runner, modernized the permissions model with JSON-encoded permissions and abstracted table configuration, and expanded telemetry with span-level events while tidying dependencies. The work yields stronger data governance, clearer security posture, improved reliability, and a smoother developer experience through better docs and tooling.

August 2025 monthly performance summary for the opensafely-core/ehrql and bennettoxford/openprescribing repositories. This period delivered production-quality features, improved reliability, and clearer documentation, driving business value through parity with production environments, safer data serialization, and more robust deployments.

July 2025 monthly summary focusing on key accomplishments, major fixes, and business impact across opensafely-core/ehrql and opensafely/documentation.

June 2025 performance summary across OpenSafely core and related repos. This month focused on stabilizing CI/CD, aligning functional testing with production architecture, cleaning up Docker and configuration, boosting data health and query performance, and expanding multi-file data handling and public API exposure. The changes reduce operational risk, improve deploy velocity, and enable scalable data processing with clearer configuration and stronger governance.

May 2025 performance summary: Across bennettoxford/openprescribing, opensafely-core/job-runner, and opensafely-core/ehrql, delivered tangible business value through reliability, security, automation, and data integrity improvements. Highlights include a new automated DBSTATUS health task with end-to-end visibility; major orchestration refactors to simplify task flow and prioritize DB health checks; security hardening for DB status checks; in-memory test DB and expanded CI coverage; and enhanced database operations with composite keys and robust upsert logic. Also fixed critical bugs impacting item processing and measure reliability, reducing risk of cascading failures in production.

April 2025 performance summary for the OpenSAFELY core job-runner and ehrql components focused on strengthening CI, Python environment hygiene, code quality, test modernization, and robust job execution flow. Delivered foundational changes enabling more reliable builds, faster feedback, better observability, and scalable architecture for multi-backend support.

March 2025 performance summary: Delivered across-repo data usability, reliability, and modernization enhancements that improve data exploration, integrity, and pipeline efficiency. Notable results include the airlock CSV view enhancements (row numbers and sticky headers) for faster data inspection; stabilized NHSBSA concessions ingestion with regex improvements and deduplication to prevent duplicates and ensure correct monthly alerts; enhanced blood glucose strips data mapping using a generic/alternative code approach to improve accuracy and coverage. Data tooling and performance were strengthened through pricing data retrieval improvements with cache invalidation and decoupled SubstitutionSet access; and the dataset generation workflow was migrated from databuilder to ehrQL, with corresponding test and configuration updates. These efforts reduce data duplication, accelerate analytics, and improve governance and reliability of core pipelines.

February 2025 saw targeted backend reliability and tooling improvements across ehrql, openprescribing, and airlock, delivering safer data pipelines, faster query execution, and more deterministic CI. Key outcomes include a robust MSSQL engine, expanded debugging tooling, generalized hashing for cache efficiency, and strengthened documentation/UX with targeted bug fixes.

January 2025: Delivered substantial business value across ehrql and openprescribing through documentation/API improvements, expanded test infrastructure, and cross-database data tooling. In ehrql, implemented documentation generation and API usage updates, expanded test infrastructure with CLI fixtures and multi-format readers, reorganized tests for CLI-first validation, and advanced API/data capabilities (single-table formats, eager iteration, multi-query support, and event-level data). Added robust test utilities, improved docs workflow, and prepared for multi-output files and event support. In openprescribing, standardized SICBL naming, protected preview data uploads to prevent overwrites, introduced a cross-database SQL translation tool, centralized PPU substitutions via SQL, and stabilized tests while cleaning CI artifacts. Collectively, these changes improve data reliability, enable cross-environment data queries, accelerate feature delivery, and bolster developer productivity.

December 2024 performance highlights focused on stabilizing the query layer, hardening data quality, and laying groundwork for upcoming features. Delivered a Dataset-centric API refactor across ehrql, improved test infrastructure and end-to-end coverage, fixed critical calculation and model stability issues, and enhanced observability and scaffolding for future capabilities across projects.

November 2024 monthly summary for OpenSafely development. Across ehrql, documentation, and OpenPrescribing, delivered a new Add-ons death API, improved documentation and API exposure, a targeted architectural refactor for maintainability, data integrity and performance hardening, and expanded testing/quality tooling. These efforts enhance analytics accuracy, developer experience, and system stability, while reducing operational risk.