Full-Stack Product Engineer (AI-Assisted)

Company
Sagan Recruitment / Early-Stage SaaS Company

Salary / Compensation

• $3,500 – $4,500 USD/month

Overview / Job Description

Sagan is an exclusive membership community connecting international talent with U.S.-based businesses. For this position, Sagan represents a small, early-stage software company developing a live SaaS product for a specific industry of small business owners.

The company is looking for its first engineer to take ownership of a substantial TypeScript codebase and help prepare the product for its next stage of growth as it begins onboarding paying customers. The role combines full-stack product engineering with AI-assisted development, with a strong emphasis on engineering judgment, code quality, testing, documentation, and independent ownership.

The engineer will work closely with a founder who uses AI coding agents to implement software from plain-English specifications. The successful candidate will similarly use AI coding agents as a daily development tool while remaining responsible for reviewing generated code, identifying incorrect solutions, debugging production systems, and making sound engineering decisions.

Responsibilities:

Product Development

• Build and maintain full-stack SaaS product features
• Implement payments and subscription functionality
• Develop self-serve signup and account creation
• Build third-party integrations including CRMs, calendars, and lead-routing systems
• Develop additional pages with SEO and indexability requirements
• Improve infrastructure and security, including CDN/origin hardening, custom domains, and CI
• Implement image processing, transformations, and cropping at scale
• Bring a second product in-house that evaluates websites and feeds results into onboarding
• Rebuild a customer-facing assistant currently operating on a third-party platform
• Contribute to LLM-powered product functionality over time

Codebase & Engineering Setup

• Replace the existing framework-boilerplate README
• Establish continuous integration where none currently exists
• Get the complete test suite passing from a clean checkout
• Create a local database setup so new developers can get started quickly
• Document the architecture of the largest subsystem
• Improve the codebase’s overall maintainability and development workflow

AI-Assisted Engineering

• Use AI coding agents as an integral part of the development process
• Direct AI agents effectively through clear instructions
• Review AI-generated code critically
• Identify when AI-generated solutions are incorrect
• Understand why generated solutions are wrong and implement appropriate alternatives
• Maintain engineering judgment rather than treating AI as a replacement for technical expertise

Testing & Documentation

• Ship changes with appropriate tests
• Review and validate implementation results
• Record engineering decisions in the shared decision log
• Document what changed, what was measured, and what was deliberately left unchanged
• Read existing comments and engineering context before modifying the codebase

Ownership & Collaboration

• Take end-to-end ownership of engineering work
• Independently investigate and troubleshoot production issues
• Challenge specifications when evidence contradicts requirements
• Communicate technical reasoning clearly in writing
• Introduce process discipline to an early-stage codebase
• Work independently while maintaining alignment with the founder

Requirements:

Experience

• Strong experience with TypeScript in strict mode
• Real-world experience with modern React frameworks, particularly Next.js App Router
• Strong experience with SQL/PostgreSQL
• Experience working with production codebases
• Strong software engineering fundamentals
• Experience independently debugging, troubleshooting, and improving production software
• Fluency with AI coding agents such as Claude Code, Cursor, Codex, or similar
• Experience using AI-assisted development as a daily working method

Technical Skills

• TypeScript
• Next.js
• React
• PostgreSQL
• Drizzle
• Zod
• Railway
• Cloudflare
• Cloudinary
• AI-assisted engineering
• Full-stack development

Skills & Competencies

• Strong engineering judgment
• Excellent written English
• Strong analytical and debugging abilities
• Ability to critically evaluate AI-generated code
• Ability to work independently
• Strong attention to correctness and code quality
• Comfortable taking end-to-end ownership
• Willingness to work on both complex and unglamorous engineering tasks
• Ability to read and understand existing technical context before making changes
• Willingness to challenge assumptions using evidence

Helpful but Not Required

• Payments / Stripe experience
• Web scraping or parsing
• Image processing
• Continuous integration
• Infrastructure engineering

Candidate Profile: You SHOULD Apply If

• You enjoy reading and understanding a codebase before modifying it
• You prioritize correctness over simply moving quickly
• You can clearly communicate when you do not have enough information rather than guessing
• You are comfortable challenging specifications when evidence suggests they are incorrect
• You can introduce engineering discipline into an early-stage codebase
• You want genuine ownership rather than simply working through a ticket queue
• You use AI to accelerate development while maintaining strong engineering judgment
• You can identify, debug, and correct AI-generated solutions
• You are comfortable owning software from implementation through testing and production improvement

You Should NOT Apply If

• You prefer highly specified tickets and a clearly defined role
• You prioritize speed over correctness
• You want to work primarily on design systems or component libraries
• You rely on AI to replace rather than accelerate your engineering expertise
• You are uncomfortable reading and debugging existing production code
• You prefer not to take ownership of infrastructure, testing, documentation, or other less glamorous engineering tasks

Other Information:

Additional Benefits / Highlights

• Fully remote
• Full-time position
• Work with an early-stage SaaS product that is already live
• Opportunity to become the company’s first engineer
• Significant end-to-end ownership
• AI-assisted engineering is the company’s actual development methodology
• Opportunity to work on SaaS, payments, integrations, infrastructure, image processing, and LLM-powered features
• Work directly within an engineering environment that emphasizes written reasoning, testing, documentation, and decision tracking
• Resume must be submitted as a text-based PDF
• Scanned documents, JPG/PNG files, and Word documents are not accepted
• Resume and introductory video must be submitted in English

Technology Stack

• TypeScript
• Next.js
• React
• PostgreSQL
• Drizzle
• Zod
• Railway
• Cloudflare
• Cloudinary

Required Skills

• AI-Assisted Engineering
• Full-Stack TypeScript Development
• Next.js
• PostgreSQL