Senior Full Stack AI-first Saas Engineer

5Blue Software; United States; Remote; USD 140,000 - 190,000; Full time

Benefits offered by this job

Flexible remote work

English classes

Medical insurance

International team

Equipment provided

Accounting support

Paid time off

Flexible payment options

Job summary

5Blue Software is hiring a Senior Full-Stack Developer for an AI-first B2B SaaS product. You’ll own features from idea to production, balancing frontend and backend work with a focus on React experiences and robust backend services.

You’ll work in an AI-enabled development environment, using Claude Code and related tools daily, collaborating with a distributed team across Europe, Israel, and Africa. Remote-friendly and product-driven.

Qualifications

• 5+ years of professional software development experience with strong backend and frontend skills.
• 2+ years of professional experience with React.
• Strong TypeScript proficiency and API framework experience (Express or Fastify).
• Production experience with microservices and cloud providers (AWS, GCP, Azure).
• Experience shipping AI-powered features in a live product.
• Experience integrating third-party REST APIs into production systems.
• Fluent English and clear communication in technical discussions.
• Background in product or SaaS companies; security/compliance knowledge is a plus.

Responsibilities

• Build and deliver full-stack features end to end using React, TypeScript, and Node.js.
• Develop frontend experiences for a complex B2B SaaS product.
• Implement backend services, APIs, business logic, and integrations.
• Develop and integrate AI-powered product features.
• Participate in system design and architectural decisions.
• Use Claude Code or similar AI tools daily to accelerate work.
• Review, debug, test, and improve AI-generated code with ownership.
• Own CI/CD and DevOps aspects for the features built.
• Collaborate with Engineering and Product to define requirements.
• Participate in Agile ceremonies; work with a distributed team.
• Communicate technical decisions confidently in English.

Skills

Node.js

React

TypeScript

Express / Fastify

API design

Microservices

AWS

PostgreSQL

MongoDB

REST APIs

AI integration

Education

CS / Software Engineering background

Tools

Claude Code

Docker

Kubernetes

LangChain

Job description

Location: Bulgaria; Croatia; Czechia; Denmark; Latvia; Poland; Portugal; Romania; Slovakia; Slovenia; Spain; Sweden; Ukraine

Hi there!
We are currently looking for a strong Full-Stack Developer-AI-First SaaS Engineer
About Us:
5Blue Software is an Israeli-Ukrainian software development company specializing in custom software development, staff augmentation, dedicated engineering teams, AI solutions, and CTO-as-a-Service. We help startups and mid-sized companies scale faster with vetted engineering talent across Europe.

About the project:
Join a fast-growing AI-first product company building a B2B SaaS platform that helps organizations simplify security, compliance, and AI governance.
The platform automates processes that traditionally require significant manual work — from evidence collection and monitoring to audit preparation and certification workflows.
You’ll join a lean, highly collaborative international engineering team distributed across Europe, Israel, and South Africa.

About the role:
We’re looking for a Senior Full-Stack Developer who is comfortable working across both frontend and backend and enjoys taking ownership of features from idea to production.
This is an AI-first engineering environment. AI is used both as part of the product and as a standard part of the development workflow. You’ll use AI-assisted development tools to accelerate implementation, debugging, testing, and refactoring while maintaining strong engineering judgment and the ability to write and understand code independently.
You’ll work closely with Engineering and Product on system design, architecture, and feature development, with a particular focus on building high-quality React experiences while contributing confidently to the backend.

What you’ll do:

• Build and deliver full-stack features end to end using React, TypeScript, and Node.js.

• Develop intuitive, performant, and scalable frontend experiences for a complex B2B SaaS product.

• Implement backend services, APIs, business logic, and third-party integrations.

• Develop and integrate AI-powered product features.

• Participate in system design and architectural decisions.

• Use AI-assisted development tools such as Claude Code or similar as part of your everyday workflow.

• Review, debug, test, and improve AI-generated code while maintaining ownership of the implementation.

• Take responsibility for the CI/CD and DevOps aspects of the features you build.

• Work closely with Engineering and Product to define requirements and technical solutions.

• Participate in Agile ceremonies and collaborate with a distributed international team.

• Communicate technical decisions clearly and confidently in English.

What we’re looking for:

• 5+ years of professional software development experience, with roughly 5+ years of experience with Node.js as a guide rather than a hard line. Real depth in a closely related stack can also count.

• 2+ years of professional experience with React as a guide.

• Strong experience with TypeScript.

• Hands-on experience with Express, Fastify, or a similar API framework.

• Strong full-stack capabilities and the ability to work comfortably across frontend and backend, even with a natural lean toward one side.

• Production experience with microservices architecture.

• Working familiarity with AWS or a comparable cloud provider such as GCP or Azure.

• Hands-on experience with both relational and non-relational databases, such as PostgreSQL and MongoDB or similar.

• Experience integrating third-party REST APIs into a production system, beyond just building your own API endpoints.

• Real experience shipping AI-powered features in a live product, not just experimenting with AI on personal projects.

• Experience using AI tools such as Claude Code or similar as a genuine part of your development workflow, balanced with the ability to write and debug code yourself, unaided, live.

• Working proficiency in DevOps, QA, and CI/CD at the level expected of a senior engineer, not a dedicated DevOps hire.

• Strong spoken English, comfortable holding a real-time technical conversation such as a system design discussion.

• A background from a product or SaaS company rather than a project-based agency. Experience in security, compliance, GRC, or developer-tools SaaS is a natural fit, though not required.

Nice to have:

• Experience with LangChain, LangGraph, or a comparable agent/AI framework.

• Python experience alongside your primary stack.

• Experience with Docker, Kubernetes, or containerization more broadly.

• A CS / Software Engineering academic background.

• A track record as the front-end "champion" on a full-stack team: someone who can carry that surface area while still holding their own on the backend.

What we offer:

• Flexible Work Environment: Opportunity to work remotely.
• 1:1 English Classes: Individual English language training.
• Premium Medical Insurance: Comprehensive health insurance.
• Great Team: Supportive, collaborative, and dynamic international team.
• Equipment Provided: All necessary equipment supplied.
• Accounting Support: Full accounting assistance in Ukraine and Poland.
• Paid Time Off: 18 days of annual vacation and 7 days of sick leave without a doctor's note.
• Flexible Payment System: Convenient payment solution with multiple withdrawal options.

If you’re a strong full-stack engineer who enjoys building real products, taking ownership, and using AI to become a more effective developer — we’d love to hear from you.