Senior Full-Stack Engineer: Scalable SaaS & AI-Ready - Remote

Socket.dev; United States; Remote; USD 140,000 - 190,000; Full time

Benefits offered by this job

Excellent PTO program

Great health benefits

Casual and friendly environment

Remote work

Job summary

Firstup is seeking a Senior Full Stack Engineer to design and deliver large-scale, multi-tenant cloud services with a focus on availability and scalable architecture. You will lead end-to-end development across frontend, backend, and data layers, and help elevate engineering quality worldwide.

Key areas include system architecture, performance, and shift-left quality. You will mentor engineers, collaborate with Product and Design, and advocate for robust engineering standards across teams.

Qualifications

• 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 across frontend, backend, and database layers.
• Polyglot mindset with familiarity in Ruby on Rails, TypeScript, Node.js, or React.js.
• Proven depth in distributed systems, multi-tenant SaaS, or related domains.
• Strong communication skills and collaboration across Product, Design, and Engineering.

Responsibilities

• Build and own scalable SaaS applications end-to-end — frontend, backend, and data layers.
• Design future-ready architectures and close gaps before they become problems.
• Drive system availability and performance across the stack.
• Champion shift-left testing and quality with unit, integration, and contract testing.
• Leverage AI-assisted tools to accelerate development while ensuring code quality.
• Mentor engineers and elevate overall engineering practices.
• Collaborate with Product and Design to translate requirements into intuitive UI and make informed trade-offs.

Skills

Full stack fluency

Frontend (React.js)

Backend (Node.js)

Ruby on Rails

TypeScript

Distributed systems

Multi-tenant SaaS

System design

Communication

Education

Bachelor's degree in Computer Science or related field

Tools

React.js

Ruby on Rails

TypeScript

Job description

Firstup is seeking a Senior Full Stack Engineer to design and deliver large-scale, multi-tenant cloud services with a focus on availability and scalable architecture. You will lead end-to-end development across frontend, backend, and data layers, and help elevate engineering quality worldwide.

Key areas include system architecture, performance, and shift-left quality. You will mentor engineers, collaborate with Product and Design, and advocate for robust engineering standards across teams.