Hi, I’m Jonathan Siles, a results-driven AI and Fullstack Engineer with 8+ years of experience building intelligent data pipelines and scalable web and mobile applications. I’m proficient in Python, Node.js, Java, Spring Boot, React, Next.js, React Native, REST APIs, and cloud platforms (Azure, AWS, GCP). I thrive in fast-paced, collaborative environments and enjoy delivering production-grade software across web and mobile platforms. I’m passionate about turning complex problems into robust, scalable solutions, collaborating with cross-functional teams, and continuously learning new technologies to drive impactful outcomes.…

Jonathan Siles

Hi, I’m Jonathan Siles, a results-driven AI and Fullstack Engineer with 8+ years of experience building intelligent data pipelines and scalable web and mobile applications. I’m proficient in Python, Node.js, Java, Spring Boot, React, Next.js, React Native, REST APIs, and cloud platforms (Azure, AWS, GCP). I thrive in fast-paced, collaborative environments and enjoy delivering production-grade software across web and mobile platforms. I’m passionate about turning complex problems into robust, scalable solutions, collaborating with cross-functional teams, and continuously learning new technologies to drive impactful outcomes.…

Available to hire

Hi, I’m Jonathan Siles, a results-driven AI and Fullstack Engineer with 8+ years of experience building intelligent data pipelines and scalable web and mobile applications. I’m proficient in Python, Node.js, Java, Spring Boot, React, Next.js, React Native, REST APIs, and cloud platforms (Azure, AWS, GCP). I thrive in fast-paced, collaborative environments and enjoy delivering production-grade software across web and mobile platforms.

I’m passionate about turning complex problems into robust, scalable solutions, collaborating with cross-functional teams, and continuously learning new technologies to drive impactful outcomes.

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Skills

Experience Level

React JS
Expert
JavaScript
Expert
AngularJS
Expert
Vue.js
Expert
TypeScript
Expert
SQL
Expert
Python
Expert
.NET
Expert
Docker
Expert
Node.js
Expert
Kubernetes
Expert
PostgreSQL
Expert
AWS
Expert
React Native
Expert
Java
Expert
HTML5
Expert
Express
Expert
GitHub
Expert
Jira
Expert
Tailwind
Expert
Azure
Expert
Spring
Expert
Redis
Expert
Bootstrap
Expert
MySQL
Expert
MongoDB
Expert
GraphQL
Expert
Google Cloud
Expert
Data Visualization
Expert
Elasticsearch
Expert
Stripe
Expert
Svelte
Expert
Power BI
Intermediate
Tableau
Intermediate
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Language

English
Fluent

Work Experience

AI & Fullstack Develope at Freelancer
June 1, 2026 - May 29, 2026
Developed an AI audio stem separation functionality using transformer-based neural networks, achieving 87% vocal isolation accuracy across 8 stem types, reducing processing time by 40% compared to baseline models through GPU optimisation on AWS. Built a NestJS job queue system using Redis to manage asynchronous audio processing tasks, supporting concurrent processing of thousands of audio jobs with real-time status tracking and webhook notifications on completion. Developed a high-performance web platform using Next.js with server-side rendering (SSR) and static site generation (SSG), improving SEO and page load speeds by 65%. Built and shipped a cross-platform mobile application using React Native and Expo, deployed on both iOS and Android with 100K+ active users. Implemented CI/CD pipelines via GitHub Actions and Azure DevOps, significantly reducing release cycle time and deployment errors across web and mobile. Optimised cloud infrastructure on Azure and AWS through auto-scaling, resulting in a 28% reduction in monthly cloud costs.
Fullstack Developer at TechNexia
January 6, 2021 - May 31, 2023
Developed multiple client-facing web applications using React.js and Next.js, delivering fast, responsive UIs with seamless API integration. Built and maintained RESTful APIs and microservices using Java Spring Boot, supporting a large active user base with consistently low response times. Integrated Spring Security for authentication and authorisation, and implemented JWT-based auth flow consumed by React frontends. Reduced front-end load times by 45% through code splitting, lazy loading, and React performance optimisation techniques. Deployed containerised Spring Boot and Next.js applications using Docker and Kubernetes on AWS, streamlining infrastructure management.
Junior Software Engineer at Google
January 5, 2020 - February 28, 2021
Contributed to internal React-based dashboards, building reusable component libraries that improved development speed across multiple teams. Developed backend services in Java Spring Boot and Python, processing millions of records daily with high reliability. Optimised SQL queries and Hibernate ORM mappings, reducing average query execution time by 50% across high-traffic internal applications. Wrote unit and integration tests using JUnit, Mockito, and Jest, significantly improving code coverage and reducing production bugs. Participated in Agile ceremonies and contributed to multiple major product releases delivered on time and within scope.

Education

Bachelor of Science in Public Health and Wellness at University of Tokyo
April 1, 2018 - March 1, 2022
Bachelor in Computer Science at Harvard Computer Online Course
April 1, 2018 - March 1, 2022

Qualifications

Azure Developer Associate (AZ-204)
August 1, 2024 - June 14, 2026
Angular – The Complete Guide (Udemy)
May 1, 2023 - June 14, 2026

Industry Experience

Software & Internet, Financial Services, Healthcare, Education, Transportation & Logistics, Computers & Electronics, Professional Services
    FULLSTACK DEVELOPER

    A rebuild of Lalals, taking an unfinished transition from WordPress to a modern stack through to launch.
    Built across a Next.js frontend, Next.js admin, and NestJS API, with work spanning development, data migration, and support through launch and growth to roughly 3M+ users.

    LALALS

    Developed the core AI engine of a voice transformation platform — custom transformer-based neural network for voice-to-voice conversion across 1,400+ voice models, AI stem separation isolating 7 instrument tracks, voice cloning from audio samples, echo & reverb removal, and an AI singing generator.