Juan Castano

Comprehensive multi-platform solution replacing legacy systems for a large-scale waste management operation

Led the complete modernization of multiple legacy systems for a major waste management company through a multi-year, enterprise-scale project. Architected and implemented a comprehensive ecosystem of interconnected applications serving different operational roles.

System Components:

• Web Application: Centralised platform for administrators and allocators to manage jobs, drivers, vehicles, and operations
• Mobile Application: React Native driver app for field operations and real-time updates
• Desktop Application: Electron-based system for tip-sites with hardware integration (scales, cameras)
• Backend API: Unified GraphQL API connecting all systems and external integrations (CRMs, third-party services)

Key Achievements:

• Established monorepo architecture and project scaffolding from inception
• Collaborated effectively across large, multi-disciplinary teams using Agile methodologies
• Managed complex stakeholder communication including project managers, testers, and business analysts
• Successfully delivered system to production with zero critical issues
• Recognized for exceptional teamwork and technical leadership throughout the project lifecycle

Project Outcomes:

• Successfully replaced multiple legacy systems with modern, interconnected solutions
• Delivered comprehensive ecosystem serving different operational roles within the organisation
• Enabled seamless integration between web, mobile, and desktop applications
• Achieved successful production deployment with zero critical issues
• Enhanced operational efficiency through centralised data management and real-time insights

Technologies used: TypeScript, React, React Native, Electron, GraphQL, NodeJS, PostgreSQL, Monorepo Architecture

High-performance CMS platform with advanced user authentication and content delivery optimisation

Developed a comprehensive CMS solution featuring role-based access control and lightning-fast content delivery. Implemented an admin portal for bulk content management and user administration, whilst ensuring secure content delivery to authenticated users only.

Key Features:

• Advanced user authentication and authorisation system
• Bulk content management capabilities
• Optimised content preloading for enhanced user experience
• Responsive design implementation

Project Outcomes:

• Delivered lightning-fast content delivery through optimised preloading
• Successfully implemented secure content access for authenticated users only
• Achieved exceptional responsive design translation from Figma designs
• Enabled efficient bulk content management and user administration
• Mastered modern CMS development practices and responsive design principles

Technologies used: TypeScript, Gatsby, Contentful, KeystoneJS, GraphQL, NodeJS, AWS Fargate, PostgreSQL, Netlify

Open source library for seamlessly connecting multiple data sources into a unified GraphQL API

Contributed to the development of an innovative open source library that enables organisations to integrate disparate data sources into a single, cohesive GraphQL API. The solution provides transparent data access regardless of underlying storage systems and includes comprehensive security controls.

Key Contributions:

• Implemented new feature requirements based on community feedback
• Resolved critical issues and bugs reported by the open source community
• Enhanced fine-grained security implementation
• Contributed to admin portal development for data visualisation and editing

Project Outcomes:

• Successfully delivered open source library enabling seamless multi-source data integration
• Provided transparent data access regardless of underlying storage systems
• Enabled organisations to query linked data entities across different systems through unified GraphQL schema
• Contributed to community-driven development with active issue resolution
• Enhanced developer experience through comprehensive admin portal functionality

Technologies used: TypeScript, GraphQL, NodeJS, Multiple Database Systems

Next.js-based progressive web application with integrated payment processing and scanning capabilities

Delivered a modern progressive web application for a soft plastics recycling company within strict time constraints. The solution replaced legacy systems whilst maintaining operational continuity and included advanced scanning capabilities for streamlined operations.

Key Responsibilities:

• Stripe payment gateway integration and processing
• Frontend implementation across multiple application pages
• Google APIs integration for enhanced functionality
• Collaborative development in a high-pressure, time-sensitive environment

Project Outcomes:

• Successfully delivered progressive web application within record-breaking timeframe
• Achieved seamless legacy system replacement with zero post-launch issues
• Implemented advanced scanning capabilities for streamlined recycling operations
• Delivered robust payment processing system with Stripe integration
• Maintained operational continuity during system transition

Technologies used: Next.js, TypeScript, Mantine, Stripe, Apollo Client, Apollo Server, GraphQL, Google APIs

Streamlines weekly repetitive tasks including automated email sending and Excel file management

Built an automation tool that handles weekly repetitive tasks like sending emails with specific information from the Internet and filling Excel files. This project demonstrates my ability to identify inefficiencies and create solutions that save time and reduce manual work.

Project Outcomes:

• Successfully automated weekly repetitive tasks, significantly reducing manual workload
• Eliminated human error in routine email sending and Excel file management
• Improved operational efficiency through intelligent task automation
• Demonstrated problem-solving skills by identifying and addressing workflow inefficiencies

Technologies used: JavaScript, Electron, Vue, NodeJS, Puppeteer

Automated web scraping application with SMS notifications for subscribers

Developed a web application that logs into websites, scrapes specific information, and sends SMS notifications to subscribers interested in that data. This project showcases my skills in web automation and cloud services integration.

Project Outcomes:

• Successfully implemented automated web scraping with reliable data extraction
• Delivered real-time SMS notification system for subscriber engagement
• Achieved seamless cloud services integration using AWS infrastructure
• Demonstrated expertise in web automation and cloud-based notification systems

Technologies used: JavaScript, Puppeteer, NodeJS, Amazon Elastic Beanstalk, Amazon SNS

Interactive web application for creating and taking multiple choice tests

Created a web application that allows users to create and take multiple choice tests for study purposes. This project demonstrates my full-stack development skills using modern cloud technologies and serverless architecture.

Project Outcomes:

• Successfully delivered interactive test creation and taking platform
• Implemented serverless architecture for scalable performance
• Achieved seamless user experience for educational purposes
• Demonstrated proficiency in modern cloud technologies and full-stack development

Technologies used: JavaScript, React, Amazon Amplify, DynamoDB, Amazon S3, GraphQL