Senior Full-Stack Developer — Agentic AI

Advanced Tech Placement; Roseland (NJ); On-site; USD 120,000 - 180,000; Full time

Job summary

Advanced Tech Placement in New Jersey is seeking a Senior Full-Stack Developer to build a brand-new agentic AI application. You will design and ship features using React and Node.js, and build infrastructure on AWS while collaborating with AI coding agents to refine implementations.

You will critically evaluate AI-generated code for correctness, architecture, and maintainability, ensuring engineering standards are met in a greenfield environment where architecture and practices evolve rapidly.

Qualifications

• Strong hands-on React and Node.js expertise.
• Hands-on AWS infrastructure experience.
• Senior-level engineering judgment for code correctness and maintainability.
• Experience evaluating AI-generated code and identifying issues.
• Ability to design non-deterministic, LLM-driven or agentic logic.
• Testing and automation aptitude with shared ownership of quality.

Responsibilities

• Design, build, and ship features for a new chat-based, agentic AI product experience.
• Develop full-stack applications using React and Node.js.
• Build and support applications and infrastructure within AWS.
• Work directly with AI coding agents in the development lifecycle.
• Critically review AI-generated code for correctness, architecture, and maintainability.
• Refine AI-generated solutions and define architecture, standards, and practices.
• Design solutions for dynamic, non-deterministic workflows driven by AI.
• Participate in testing and automation with shared ownership of quality.
• Collaborate in small pods with other engineers and AI agents.

Skills

React

Node.js

AWS

AI-generated code

Testing & automation

Architecture

Senior engineering judgment

Non-deterministic / agentic logic

Job description

Senior Full-Stack Developer - Agentic AI ProductPosition Overview

We are seeking a Senior Full-Stack Developer to help build a brand-new agentic AI application within a growing AI-driven software ecosystem.

This is a greenfield product where large language models (LLMs) and AI agents dynamically influence application behavior and user workflows rather than relying exclusively on predefined, deterministic code paths. The team is defining architecture, development standards, and best practices as the platform evolves.

The ideal candidate has deep React and Node.js expertise, AWS infrastructure experience, and strong senior-level engineering judgment. A critical part of this role is working alongside AI coding agents and being able to critically evaluate AI-generated code for correctness, structure, architecture, maintainability, and adherence to engineering standards.

The ability to recognize when functional AI-generated code is not the right implementation — and determine how it should be corrected — is one of the most important capabilities for this position.

Key Responsibilities

• Design, build, and ship features for a new chat-based, agentic AI product experience.
• Develop full-stack applications using React and Node.js.
• Build and support applications and infrastructure within AWS.
• Work directly with AI coding agents as part of the software development lifecycle.
• Critically review AI-generated code and identify issues related to correctness, architecture, design patterns, maintainability, scalability, and engineering standards.
• Correct and refine AI-generated solutions rather than relying on generated output at face value.
• Help define architecture, coding standards, patterns, and development practices for a greenfield product.
• Design solutions for dynamic, non-deterministic, LLM-driven workflows rather than relying exclusively on traditional fixed application logic.
• Participate in testing and automation as part of a collaborative engineering model with shared ownership of quality.
• Work closely with engineers in small, highly collaborative development pods.
• Help determine how agentic application flows should be structured, tested, maintained, and scaled as the product evolves.

Required Qualifications

• Strong hands-on React expertise.
• Strong hands-on Node.js expertise.
• Strong full-stack software engineering background.
• Hands-on AWS infrastructure experience.
• Demonstrated senior-level engineering judgment with the ability to independently evaluate code for correctness, structure, architecture, maintainability, scalability, and adherence to engineering standards.
• Experience working with AI-generated code, including the ability to identify mistakes, poor patterns, or inappropriate implementations and determine how they should be corrected.
• Strong understanding of software architecture, design patterns, code quality, and engineering best practices.
• Ability to reason about and develop non-deterministic, LLM-driven or agentic application logic, rather than relying solely on traditional fixed-flow application patterns.
• Testing and automation aptitude, with willingness to take shared ownership of application quality.
• Ability to operate effectively in an early-stage, greenfield environment where architecture, standards, and product requirements are actively evolving.
• Strong problem-solving skills, adaptability, and ability to work independently with limited direction.

Preferred Qualifications

• Experience developing AI-powered, LLM-driven, conversational, or agentic applications.
• Experience with LLM tool/function calling, agent orchestration, or dynamic agent workflows.
• Experience working within an AI-native or AI-assisted SDLC.
• Experience helping establish engineering standards or architecture for new products.
• Experience with modern testing and automation frameworks.
• Experience within HCM, HR technology, payroll, or related enterprise software.

Team & Environment

The team operates in small development pods, typically consisting of 2-3 engineers working alongside AI coding agents. Developers use AI as an active part of the engineering process while applying their own technical judgment to ensure generated solutions meet production engineering standards.

This is an early-stage, greenfield initiative, so the successful candidate will be comfortable working in an environment where conventions, architecture, and best practices are actively evolving.

Ideal Candidate

The strongest candidate is a senior React/Node.js engineer with excellent technical judgment who is comfortable building software differently than in a traditional development environment.

The key differentiator is the ability to look at code — including functional code produced by AI — and determine whether it is actually the right solution. You should be able to spot mistakes, architectural issues, poor patterns, maintainability concerns, or deviations from engineering standards and confidently determine how the implementation should be improved.

You should also be comfortable reasoning about dynamic, non-linear, agentic application behavior, taking ownership of testing and quality alongside development, and helping establish engineering standards for a product being built from the ground up.