Oliver Brennan

Built the entire pathway runtime from scratch across 3 repos: if-else branching with AND/OR groups, outcome nodes, update patient/entry nodes, skip/cancel APIs with consent-withdrawal handling, scheduled start from reference date, node-execution editing with cascade rescheduling, and soft-delete. The system drives automated clinician workflows for NHS national pathway go-lives.

Rebuilt the frontend deployment infrastructure end-to-end: migrated to pnpm with single-artefact promotion (build once, promote per-region via config.json), GitHub App tokens for secure automation, threaded Slack deploy notifications, pnpm 11 + Node 24 runtime upgrades, consolidated preview deploys, and serialised production builds to eliminate version tag race conditions.

Led two consecutive major PrimeNG upgrades across the entire frontend and design system. v17 to v19 in December (theme reset, component regressions), then v19 to v20 in June (Sidebar to Drawer, Dropdown to Select, OverlayPanel to Popover, removed sub-packages). Each required migrating 100+ components.

Bootstrapped the internal design system site from zero: Firebase Hosting with auto-deploy on merge, runtime config for environment switching, Jest testing, global command palette search (Cmd/Ctrl+K), PrimeNG v20 upgrade. Added a Cursor rule to enforce Islay design standards across the frontend codebase.