Senior Full-Stack Engineer - Remote & Impactful SaaS

Firstup; United States; On-site; USD 120,000 - 190,000; Full time

Benefits offered by this job

Excellent PTO

Great health benefits

Casual environment

Remote work

Job summary

Firstup is seeking a Senior Full Stack Engineer who thrives at scale and ownership. You will design and deliver large‑scale, multi‑tenant cloud services with a relentless focus on availability and clean architecture.

You will own features across frontend, backend, and data layers, mentor peers, and collaborate with Product and Design to translate requirements into intuitive UI. This role emphasizes performance, shift‑left testing, and AI‑assisted tooling within a strong engineering culture.

Qualifications

• 5+ years building reliable, performant applications and microservices.
• Full stack fluency across frontend, backend, and database layers.
• Experience with Ruby on Rails, TypeScript, Node.js, or React.js.
• Strong communication and collaboration across teams.

Responsibilities

• Core Engineering & Ownership: Build and own scalable SaaS applications end‑to‑end.
• System Architecture: Design future‑ready architectures and close gaps early.
• Performance & Reliability: Improve availability and efficiency across the stack.
• Shift Left Testing & Quality: Embed unit/integration/contract testing early.
• AI Integration: Leverage AI tools to accelerate development with care for code quality.
• Leadership: Drive best practices and mentor engineers to raise the bar.
• Collaboration (Product & Design): Translate requirements into intuitive UI.
• Collaboration (Engineering Standards): Promote engineering standards across teams.

Skills

Full stack fluency

React.js

TypeScript

Node.js

Ruby on Rails

Distributed systems

Education

Bachelor's degree in Computer Science

Job description

Firstup is seeking a Senior Full Stack Engineer who thrives at scale and ownership. You will design and deliver large‑scale, multi‑tenant cloud services with a relentless focus on availability and clean architecture.

You will own features across frontend, backend, and data layers, mentor peers, and collaborate with Product and Design to translate requirements into intuitive UI. This role emphasizes performance, shift‑left testing, and AI‑assisted tooling within a strong engineering culture.