Full Stack Platform Engineer

Senior Full Stack AI Platform Engineer (Contract)

Contract Type: Independent Contractor / Consultancy Engagement

Location: Hybrid - 2 days per week for first 1-2 month, then remote - Frankfurt

Duration: Project-Based Contract

Rate: Competitive, dependent on experience

Project Overview

We are seeking an experienced Senior Full Stack AI Platform Engineer to undertake an independent technical engagement involving the audit, hardening, migration, and enhancement of an existing AI application platform.

This project requires a highly skilled contractor capable of reviewing and optimizing an established AI harness codebase, implementing cloud-native deployment infrastructure, developing automated testing frameworks, and translating Figma designs into production-ready frontend experiences.

The successful contractor will independently deliver secure, scalable, and maintainable software solutions while leveraging their own expertise, equipment, and methodologies to achieve defined project outcomes.

Key Responsibilities

Backend Development & Codebase Hardening

• Conduct a comprehensive technical audit of an existing AI harness codebase.
• Refactor Python and JavaScript/TypeScript applications to improve maintainability, performance, and scalability.
• Develop and maintain FastAPI backend services and Node.js integration layers.
• Implement secure coding practices, input validation frameworks, authentication controls, and secrets management solutions.
• Identify and remediate technical debt and security vulnerabilities.

AWS Migration & Infrastructure Engineering

• Containerize application components using Docker and multi-stage build processes.
• Plan and execute migration from local development environments into AWS cloud infrastructure.
• Configure and optimize deployment architectures for reliability and scalability.
• Implement CI/CD workflows using tools such as GitHub Actions or Azure DevOps.
• Establish automated deployment and release processes.

Testing & Quality Assurance

• Design and implement automated testing strategies across the application stack.
• Build and maintain unit, integration, and API test suites using:
• Pytest
• Jest
• HTTPX
• Implement static code analysis, linting, formatting, and quality controls including:
• Ruff
• Black
• ESLint
• Ensure code quality, reliability, and production readiness through automated validation processes.

Frontend Development & Figma Integration

• Translate Figma designs, component specifications, and design tokens into responsive frontend applications.
• Develop modern user interfaces using:
• TypeScript
• HTML5
• CSS3
• Build AI-focused user experiences, including:
• Conversational interfaces
• AI output dashboards
• Data visualization components
• Ensure accessibility, responsiveness, and consistent user experience across devices.

Documentation & Knowledge Transfer

• Produce comprehensive technical documentation covering:
• System architecture
• Infrastructure configurations
• API specifications
• Deployment workflows
• Application maintenance procedures
• Provide structured knowledge transfer materials to support long-term platform ownership.

Required Skills & Experience

• Demonstrable experience with Python and FastAPI development.
• Strong Node.js and TypeScript expertise.
• Hands-on experience deploying applications within AWS environments.
• Deep understanding of Docker containerization and cloud-native architectures.
• Experience implementing CI/CD pipelines using GitHub Actions and/or Azure DevOps.
• Strong knowledge of software security principles and secure coding practices.
• Proven experience building automated testing frameworks and quality assurance pipelines.
• Experience converting Figma designs into production-ready frontend applications.
• Strong understanding of modern frontend architecture and responsive design.
• Experience working independently on complex software engineering engagements.

Desirable Experience

• AI/ML platform development experience.
• Experience building conversational AI applications.
• Knowledge of infrastructure-as-code and cloud automation frameworks.
• Familiarity with modern observability and monitoring solutions.
• Experience working on enterprise software modernization projects.

Deliverables

The contractor will be responsible for delivering:

• Audited and hardened application codebase.
• Refactored FastAPI and Node.js services.
• Dockerized application architecture.
• AWS deployment and infrastructure configurations.
• Automated CI/CD pipelines.
• Comprehensive automated test suites.
• Production-ready frontend modules implemented from Figma designs.
• Complete technical and operational documentation.

Success Criteria

Successful delivery will result in:

• A secure, production-ready AI platform.
• Cloud-deployed AWS infrastructure.
• Fully automated testing and deployment processes.
• Responsive frontend experiences aligned with approved Figma designs.
• Comprehensive documentation supporting ongoing maintenance and future development.

Please apply on Linkedin.