Freelance Full Stack Machine Learning Engineer Jobs in Mokena, IL

Full Stack Developer (React, Python & FastAPI)

Location: Remote (Preferred: Philippines, Latin America, or North America)
Employment Type: Full-Time / Contract
Company: Performacentric

About Performacentric

Performacentric helps small and mid-market organizations improve profitability, efficiency, visibility, and customer performance through custom AI solutions, intelligent automation, and connected business systems. We build AI agents, copilots, integrations, and business applications that eliminate manual processes and enable faster, data-driven decision making.

We are seeking a highly motivated Full Stack Developer to help design, build, and maintain modern web applications and AI-powered solutions for our clients and internal platforms.

Position Overview

The Full Stack Developer will be responsible for building and maintaining applications across the entire technology stack, including frontend user interfaces, backend APIs, database architecture, and cloud deployment.

The ideal candidate is equally comfortable developing modern React applications and building scalable Python/FastAPI backend services. Candidates with experience in machine learning, large language models (LLMs), AI agents, and PostgreSQL will receive strong consideration.

This position offers the opportunity to work on cutting-edge AI initiatives, business automation platforms, and next-generation enterprise applications.

Key Responsibilities
Frontend Development

• Design and develop responsive web applications using React.
• Build reusable UI components and front-end libraries.
• Consume REST and GraphQL APIs.
• Optimize applications for performance, scalability, and usability.
• Collaborate with designers and stakeholders to create exceptional user experiences.

Backend Development

• Develop and maintain APIs using Python and FastAPI.
• Design scalable microservices and backend architectures.
• Implement authentication, authorization, and security best practices.
• Build integrations with third-party platforms and business applications.
• Create automated workflows and data processing pipelines.

Database Development

• Design and optimize PostgreSQL databases.
• Develop efficient queries, indexes, and stored procedures.
• Support data migration and ETL processes.
• Ensure data integrity, security, and performance.

AI & Automation Development

• Assist in the development of AI agents and copilots.
• Integrate Large Language Models (LLMs) into business applications.
• Build retrieval-augmented generation (RAG) solutions.
• Support prompt engineering and AI workflow automation.
• Develop integrations between AI services and enterprise systems.

DevOps & Quality

• Participate in CI/CD pipeline development and maintenance.
• Perform testing, debugging, and code reviews.
• Monitor application performance and reliability.
• Contribute to cloud infrastructure and deployment automation.

Required Qualifications

• 3+ years of professional software development experience.
• Strong proficiency in React.
• Strong proficiency in Python.
• Experience building APIs using FastAPI.
• Experience with HTML5, CSS3, JavaScript, and TypeScript.
• Familiarity with Git and GitHub-based development workflows.
• Understanding of RESTful API design principles.
• Experience working with relational databases.
• Strong problem-solving and debugging skills.
• Excellent written and verbal English communication skills.

Preferred Qualifications

Candidates possessing one or more of the following will receive preference:

• Experience with PostgreSQL.
• Machine Learning Engineering experience.
• Experience deploying or fine-tuning open-source LLMs.
• Experience with Llama models and related tooling.
• Experience building AI agents and autonomous workflows.
• Knowledge of vector databases and RAG architectures.
• Experience with LangChain, LlamaIndex, CrewAI, AutoGen, or similar frameworks.
• Experience with Docker and containerized deployments.
• Experience with cloud platforms such as AWS, Azure, or Google Cloud.
• Experience with CI/CD pipelines and DevOps practices.
• Familiarity with n8n or workflow automation platforms.

Technical Stack
Required

• React
• Python
• FastAPI
• Git/GitHub
• REST APIs
• HTML/CSS/JavaScript

Preferred

• PostgreSQL
• Llama LLM
• LangChain
• LlamaIndex
• Docker
• AWS
• Azure
• Vector Databases
• Machine Learning Frameworks

Success Metrics

The successful candidate will:

• Deliver production-ready features on schedule.
• Develop scalable and maintainable code.
• Build reliable APIs and integrations.
• Contribute to AI-powered applications and automation solutions.
• Maintain high standards for code quality, testing, and documentation.
• Collaborate effectively across technical and business teams.

What We Offer

• Opportunity to work on cutting-edge AI and automation projects.
• Exposure to modern AI agent and LLM technologies.
• Flexible remote work environment.
• Opportunity for career growth within a rapidly growing AI-focused company.
• Direct collaboration with company leadership and clients.
• Meaningful impact on products that help businesses transform how they operate.

How to Apply

Please submit:

1. Resume/CV
2. GitHub profile (required)
3. Portfolio or examples of recent projects
4. Brief description of your experience with React, Python, FastAPI, PostgreSQL, and AI/ML technologies
5. Any experience deploying or working with Llama-based LLMs or AI agents

Performacentric is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all team members.