Senior Full-Stack Software Engineer (Frontend-Focused)

Tassel is seeking a Senior Full-Stack Software Engineer with a strong frontend focus to support greenfield development and legacy modernization projects. The role primarily involves building and modernizing frontend applications with React, Next.js, and TypeScript, while contributing to backend services, cloud deployment, testing, technical direction, mentoring, and collaboration.

Responsibilities:

• Contribute senior-level expertise to the frontend rewrite of a legacy application using React, Next.js, and TypeScript
• Define and implement best practices for frontend performance, accessibility, and maintainability
• Build and maintain automated testing suites with Vitest and Playwright
• Collaborate with UI/UX designers and product managers to deliver intuitive, high-quality user experiences
• Contribute to backend services in C#/.NET and SQL Server as needed to support frontend functionality
• Support containerization and cloud deployment with Docker and Azure App Services (or Kubernetes)
• Mentor engineers and participate in code reviews and technical architecture discussions
• Enable increased agentic development and debugging through iterative architectural, observability, and process improvements

Requirements:

• 7+ years of software engineering experience with strong expertise in React, Next.js, and TypeScript
• Strong understanding of frontend architecture, performance, and accessibility best practices
• Experience modernizing or rewriting legacy applications
• Working knowledge of modern .NET applications (or equivalent) and SQL Server for backend integration
• Familiarity with CI/CD pipelines such as Azure DevOps or GitHub Actions
• Hands-on experience with containerization (Docker) and/or container deployment/orchestration (Azure App Service, Kubernetes, etc)
• Strong collaboration, communication, and mentoring skills
• Knowledge of distributed systems and cloud architecture
• Familiarity with agentic coding tooling such as Claude Code