* 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* Identify and deprecate outdated libraries and plugins.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