Note: The job is a remote job and is open to candidates in USA. Firstup is an intelligent employee communications platform that helps organizations improve employee experience and engage their workforce. The Senior Full Stack Engineer will design, build, and own scalable multi-tenant cloud services across frontend, backend, and data layers while driving availability, performance, testing, and architectural quality. The role also includes mentoring engineers, collaborating with Product and Design, and advancing engineering standards across teams.

Responsibilities

• Build and own scalable SaaS applications end-to-end — frontend, backend, and data layers. Write production-grade code that is reliable, readable, efficient, and testable. Raise the bar through thoughtful code reviews and comprehensive documentation
• Design future-ready architectures and proactively close gaps before they become problems
• Drive system availability and performance — investigate, analyze, and resolve reliability issues across the stack. Recognize opportunities and advocate for better performance and efficiency of software, systems, and processes across teams
• You champion a rigorous 'shift-left' quality culture, embedding comprehensive testing—unit, integration, and contract—early and continuously in the development lifecycle, not as an afterthought
• Leverage and advocate for AI-assisted tools (e.g., GitHub Copilot, Claude) to accelerate development while maintaining rigorous engineering judgment and accountability for code correctness
• Drive team-wide best practices, conduct quality code reviews, and mentor engineers to elevate overall engineering quality
• Partner with Product and Design to translate requirements into intuitive UI, making informed technical trade-offs in the face of ambiguity
• Champion engineering best practices across teams and collaborate on solving complex, high-impact problems

Skills

• Bachelor's degree in Computer Science or related field, or equivalent experience
• 5+ years building reliable, performant applications and microservices in production environments. Proven full stack fluency - you're comfortable across frontend, backend, and the database layer
• A polyglot mindset — you evolve with the tech. Familiarity with Ruby on Rails, TypeScript, Node.js, or React.js is a strong plus
• Proven full-stack experience across frontend (React.js), backend, and database layers
• Technical depth in at least one engineering domain: distributed systems, multi-tenant SaaS, application databases, networking, security, serverless, event streaming, or similar
• A genuine drive to build beautiful, intuitive products with the customer always in focus. Innate curiosity — you love learning and have a desire to teach and lift others. Strong communication skills and openness to collaborative idea-sharing across teams
• Familiarity with Ruby (including Ruby on Rails), TypeScript, Node.js, or React.js is a strong plus

Benefits

• Excellent PTO program
• Great health benefits
• A casual and friendly environment
• Remote work
• A leadership team who truly believes in your growth – both personally and professionally

Company Overview

Company H1B Sponsorship