Lead Full Stack Developer (React/.NET)

STACK IT Recruitment • Canada

No Relocation

Posted: February 12, 2026

Job Description

🛠️Are you a hands-on React leader who enjoys owning front-end architecture while staying close to backend system design?

We are hiring a Lead Full Stack Developer with a strong front-end focus to lead UI architecture and development across our enterprise applications. This role requires deep, hands-on expertise in React and modern front-end engineering practices, along with solid backend experience in C#, ASP.NET Core, Entity Framework, and SQL Server.

While this is a full-stack position, the primary responsibility is ownership of the front-end architecture, defining standards, modernizing legacy UI layers, and building scalable, high-performance React applications. Backend expertise is essential to ensure effective API design, data modeling alignment, and end-to-end system performance within a Microsoft technology stack.

This is a high-impact opportunity within an established U.S.-based financial/professional services organization that has spent over 30 years delivering financial audit and cost-recovery solutions to Fortune 500 clients.

💻 Who You Are:

A senior full-stack engineer who has led architectural direction within complex enterprise environments
A front-end–leaning technical leader with deep, hands-on expertise in React, responsible for designing and scaling production-grade UI platforms
Proven experience modernizing legacy or monolithic applications into modular, maintainable, service-oriented architectures
Equally comfortable defining architectural standards and contributing high-quality production code
Strong command of API design, data modeling, and backend performance optimization within the Microsoft stack
Experienced leading distributed engineering teams and driving technical alignment across cross-functional stakeholders
Pragmatic in execution, able to balance long-term architectural integrity with delivery timelines and business priorities

📍 Work Type:

Location: Ontario (Remote)
Vacancy Type: This role is a newly created position

🛠️Are you a hands-on React leader who enjoys owning front-end architecture while staying close to backend system design?We are hiring a Lead Full Stack Developer with a strong front-end focus to lead UI architecture and development across our enterprise...

🎯 What You’ll Do:

Lead the architecture and implementation of scalable React applications using TypeScript and modern design patterns
Establish reusable component libraries and enforce UI engineering standards
Drive migration of legacy UI systems to modern React-based solutions
Implement advanced state management patterns such as Redux or Context API
Optimize client-side performance, rendering efficiency, and application scalability
Design and enhance RESTful APIs using ASP.NET Core
Develop and optimize data access layers using Entity Framework
Write and tune complex SQL queries, stored procedures, and indexing strategies
Ensure efficient data flow between UI and backend services
Lead the evolution of a shared .NET codebase toward scalable, service-oriented architecture
Establish standards for maintainability, security, and performance across the stack
Guide CI/CD practices and branching strategies using Azure DevOps
Mentor developers, conduct code reviews, and elevate overall engineering quality
Collaborate with product leadership to translate business requirements into robust technical solutions
Support production stability through troubleshooting and performance optimization
Collaborate on the integration of AI-powered capabilities into user workflows where appropriate
Contribute to the implementation of AI-enhanced features leveraging Azure AI Services or OpenAI APIs when required
Identify opportunities to improve internal engineering productivity through responsible AI tooling

⭐ What We’re Looking For:

A minimum of 7 years of progressive full-stack software development experience in enterprise environments
Proven experience as a Lead Developer, Technical Lead, or Principal Engineer
Deep, hands-on expertise in React (mandatory), including Hooks, functional components, TypeScript, modern JavaScript (ES6+), state management, and UI performance optimization
Strong backend experience with C#, ASP.NET Core, Entity Framework, and SQL Server (data modeling, query optimization, indexing, performance tuning)
Experience designing and consuming RESTful APIs within distributed systems
Familiarity with Microsoft Azure and Azure DevOps CI/CD pipelines
Demonstrated success modernizing legacy enterprise systems
Strong understanding of enterprise security and authentication/authorization frameworks
Excellent communication, leadership, and stakeholder engagement skills, with the ability to influence technical direction and drive engineering excellence
Exposure to integrating AI or ML services into enterprise applications (Azure AI, OpenAI APIs, or similar) is considered an asset

🔥 What Makes This Role Exciting

True Technical Ownership: Lead the design and evolution of enterprise-scale React applications within a complex full-stack ecosystem
AI-First Innovation: Opportunity to embed AI into real enterprise workflows
Transformation Stage: Shape the next generation of a 30-year-established organization
High Visibility: Your work directly impacts enterprise clients and internal growth

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