Senior Frontend Engineer — Payments / Transaction UIs 12-month contract · Hybrid, downtown Toronto (3 days onsite) · T4

About the Role

We are looking for a Senior Frontend Engineer to help design and build the user-facing applications that power a real-time payments platform at a major fintech. In this role, you will create secure, intuitive, and high-performance interfaces for payment workflows, transaction management, approvals, reconciliation, reporting, and operational tooling.

You will work closely with backend engineers, product managers, designers, compliance, and operations teams to deliver frontend systems that make complex financial workflows understandable and efficient. This is an ideal role for an engineer who enjoys building polished, reliable product experiences on top of sophisticated backend and transactional systems.

Responsibilities

• Design, build, and maintain modern web applications for payment management, transaction monitoring, approvals, reconciliation, and reporting
• Develop responsive, scalable, and maintainable frontend applications using React.js
• Translate complex payment and financial workflows into intuitive user interfaces and operational dashboards
• Collaborate with backend engineers to integrate APIs for payment initiation, transaction status, ledger views, settlement tracking, and exception handling
• Build reusable UI components, design patterns, and frontend architecture that support long-term product scalability
• Ensure strong application performance, accessibility, responsiveness, and cross-browser compatibility
• Implement secure frontend patterns for authentication, authorization, session management, and sensitive financial data handling
• Work closely with design and product teams to refine user journeys for operations, finance, compliance, and customer-facing workflows
• Contribute to frontend testing strategy, including unit, integration, and end-to-end testing
• Improve observability and debugging workflows for frontend applications
• Participate in code reviews, technical design discussions, incident response, and release planning
• Mentor other engineers and help establish frontend best practices across the team

Required Qualifications

• 5+ years of professional software engineering experience, with significant frontend engineering experience in production environments
• Strong proficiency in JavaScript and/or TypeScript
• Deep hands-on experience building web applications with React.js
• Strong understanding of modern frontend architecture: component design, state management, data fetching patterns, routing, error handling, and performance optimization
• Experience integrating frontend applications with REST APIs and backend services
• Experience building complex business applications, internal tools, dashboards, or workflow-driven UIs
• Strong understanding of frontend security best practices, especially around authentication, authorization, and handling sensitive data
• Experience writing robust automated tests for frontend applications
• Strong knowledge of responsive design, accessibility, and cross-browser compatibility
• Strong communication skills and ability to collaborate closely with product, design, and backend teams

Preferred / Nice to Have

• Experience building payments, fintech, banking, or other transaction-heavy product experiences
• Familiarity with financial workflows such as transaction approvals, reconciliation, settlements, account activity, and reporting
• Experience building operational dashboards, admin consoles, or compliance tooling
• Experience with TypeScript, modern component libraries, and design systems
• Familiarity with real-time UI patterns such as live transaction status updates, alerts, and event-driven data refresh
• Exposure to Temporal.io concepts or workflow-driven product experiences where long-running backend processes must be surfaced clearly in the UI
• Exposure to blockchain, digital asset, or stablecoin products and their related frontend workflows
• Experience working in regulated or security-sensitive environments

Technical Environment

• Frontend: React.js, JavaScript / TypeScript
• APIs: RESTful services
• Architecture: Component-based UI, stateful workflows, dashboard and operational interfaces
• Testing: Unit, integration, and end-to-end testing
• Infrastructure: Modern CI/CD workflows, cloud-hosted web applications
• Optional Exposure: fintech/payments integrations, Temporal.io-backed workflows, blockchain or digital asset infrastructure

What You'll Work On

• Web applications for initiating and managing payments
• Transaction dashboards showing payment lifecycle, status, failures, retries, and settlement states
• Approval and exception-management interfaces for finance, operations, and compliance teams
• Reconciliation and reporting views for internal stakeholders
• Account and balance views tied to payment activity
• Admin tools for managing users, permissions, workflows, and operational controls
• Frontend experiences that surface complex backend orchestration in a simple, actionable way