• Location: Remote (UK) • Duration: 2-3 months • Start: 21st July 2025 • Engagement: Outside IR35 • 5 Years ember experience required (Minimum requirement) The Opportunity A well-established financial services product business is looking for a Senior Ember.js Engineer to lead a critical upgrade project across its legacy Ember applications. These applications are part of a wider FX payments back-office platform, with components that have not been updated in several versions and are now reliant on unsupported versions of Ember.js and Node.js. This is a focused engineering engagement. You’ll work within a mono-repo ecosystem, modernising the codebase, resolving dependencies, and ensuring successful delivery of a clean, stable, and production-ready upgrade. What is Required. • Working closely with internal engineering leadership and DevOps support, you will: • Upgrade Ember.js from ~v3.20.5 to Ember 6.x (Octane). • Upgrade Node.js to v20+ across all associated packages. • Migrate and validate shared packages within a monorepo (Lerna/Yarn Workspaces). • Run and maintain comprehensive test coverage (unit, integration, and UAT). • Identify and deprecate outdated libraries and plugins. • Optionally consolidate “common” and “domain-common” packages into a single repo (without impacting delivery timelines) Tech Stack: • Frontend: Ember.js (Octane), Glimmer, Handlebars • Tooling: Lerna, Yarn Workspaces, ESLint, Prettier • Testing: QUnit, qunit-dom, ember-qunit • CI/CD: AWS Amplify • Auth: Keycloak (OAuth2 integration) • Languages: TypeScript, JavaScript • Misc: Ember Engines, Babel, Sass, ember-auto-import, ember-fetc Skill-Set • Deep experience upgrading and maintaining Ember.js applications (ideally 3.x → 5.x/6.x). • Solid grasp of Node.js environments and version migrations (especially v20+). • Familiarity with monorepo structures, including Lerna and Yarn Workspaces. • Experience working with Ember Engines and component libraries. • Strong testing mindset – you’ve worked with QUnit or equivalent test runners in Ember. • Good communicator – able to work autonomously and update stakeholders clearly. Deliverables • Technical Upgrade Plan • Comprehensive Test Plan and Cases • Clean builds and validated UAT release • Post-upgrade performance and stability report