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I have been involved in passionate programming ventures for over 10 years, and my enjoyment in helping others hasn't diminished at all. The more technologies I work with, the more excited I get about conquering new challenges and goals. I specialize in web development, systems integrations, database systems, workflow automations, and process optimizations. I also have a solid understanding of business analysis, solution architecture, and design. Over the years, I've worked on SaaS products, marketplaces, healthcare, insurance, travel portals, stock market ERP solutions, and mobile apps using React Native. Make no mistake, I've been developing for a long time and you can trust I'll get the job done right.…I have been involved in passionate programming ventures for over 10 years, and my enjoyment in helping others hasn't diminished at all. The more technologies I work with, the more excited I get about conquering new challenges and goals. I specialize in web development, systems integrations, database systems, workflow automations, and process optimizations. I also have a solid understanding of business analysis, solution architecture, and design. Over the years, I've worked on SaaS products, marketplaces, healthcare, insurance, travel portals, stock market ERP solutions, and mobile apps using React Native. Make no mistake, I've been developing for a long time and you can trust I'll get the job done right.

Jonas Keller

Programmer, Full Stack Developer, Developer, +2

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I have been involved in passionate programming ventures for over 10 years, and my enjoyment in helping others hasn't diminished at all. The more technologies I work with, the more excited I get about conquering new challenges and goals. I specialize in web development, systems integrations, database systems, workflow automations, and process optimizations. I also have a solid understanding of business analysis, solution architecture, and design. Over the years, I've worked on SaaS products, marketplaces, healthcare, insurance, travel portals, stock market ERP solutions, and mobile apps using React Native. Make no mistake, I've been developing for a long time and you can trust I'll get the job done right.…I have been involved in passionate programming ventures for over 10 years, and my enjoyment in helping others hasn't diminished at all. The more technologies I work with, the more excited I get about conquering new challenges and goals. I specialize in web development, systems integrations, database systems, workflow automations, and process optimizations. I also have a solid understanding of business analysis, solution architecture, and design. Over the years, I've worked on SaaS products, marketplaces, healthcare, insurance, travel portals, stock market ERP solutions, and mobile apps using React Native. Make no mistake, I've been developing for a long time and you can trust I'll get the job done right.

Available to hire

I have been involved in passionate programming ventures for over 10 years, and my enjoyment in helping others hasn’t diminished at all. The more technologies I work with, the more excited I get about conquering new challenges and goals.

I specialize in web development, systems integrations, database systems, workflow automations, and process optimizations. I also have a solid understanding of business analysis, solution architecture, and design. Over the years, I’ve worked on SaaS products, marketplaces, healthcare, insurance, travel portals, stock market ERP solutions, and mobile apps using React Native. Make no mistake, I’ve been developing for a long time and you can trust I’ll get the job done right.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Language

Norwegian

Advanced

English

Advanced

Work Experience

Senior Software Engineer at Upwork Freelancer

May 1, 2025 - July 14, 2025

Led development of core features for Scratchpay, a modern financing platform for pet care, enabling seamless connections between pet owners and veterinary clinics. Built secure user authentication, streamlined clinic discovery, and integrated flexible payment workflows, improving application throughput by 60%. Focused on delivering transparent, HIPAA-compliant user experiences with optimized backend logic and secure payment integration. Developed and maintained Hutano, a HIPAA-compliant telehealth platform enabling patients to book appointments, access medical records, and attend virtual consultations. Designed intuitive front-end interfaces using React and Blazor, restructured backend logic to improve data synchronization and patient-provider matching accuracy, and migrated legacy workflows to Azure Functions, boosting platform scalability and reducing cloud infrastructure costs by 40%. Migrated V1 Digital Marketing System from Noloco + Make.com to a custom-built V2 stack using Supaba

Full Stack Engineer at Innovena

June 1, 2024 - July 14, 2025

Leveraged AWS cloud services for reliable and secure hosting of the financial management system, achieving 99.9% uptime and ensuring high availability and scalability. Utilized MySQL Server, PostgreSQL, and MongoDB, implementing GraphQL for efficient API query management, reducing query response times by 40%. Utilized AWS CI/CD services to automate build, test, and deployment processes, significantly accelerating release cycles by 30%. Applied Test-Driven Development (TDD) practices with the React Testing Library, reducing bugs by 50% and enhancing maintainability of the frontend architecture. Mentored over 5 junior developers and contributed to 20 open-source projects on GitHub, fostering team growth and community collaboration.

Full Stack Developer at LANARS

July 1, 2023 - July 14, 2025

Optimized caching with Redis and enhanced real-time data exchange via a custom Socket library, reducing application downtime from 5 seconds to 1 second in the patient management system. Constructed a HIPAA-compliant patient management system using Python and FastAPI, improving patient registration efficiency by 40% and reducing appointment scheduling time by 30%. Led a UI redesign using React, React Native, and Tailwind CSS, increasing user engagement metrics by 30%. Enhanced the design and deployment of efficient DataMarts using MySQL Server architecture, achieving a reduction in report generation times by an average of 30 seconds for users. Championed DevOps practices by automating pipelines and deployments with Azure DevOps, accelerating development cycles by 25% and enhancing product quality.

Software Developer at CatWare

August 1, 2020 - July 14, 2025

Worked closely with designers to ensure 95% consistency between design and development, translating UI/UX designs into fully functional websites using HTML, CSS, jQuery, and Bootstrap. Collaborated with the team to gather software requirements and contributed to development processes, leading to a 15% improvement in project delivery times. Implemented complex user interface effects, animations, and custom plugins using jQuery, improving site interactivity and functionality, resulting in a 20% increase in user engagement. Translated Figma designs into React.js components, ensuring pixel-perfect alignment with design specifications and achieving a 95% design accuracy rate. Developed over 50 pixel-perfect HTML pages using pure CSS and JavaScript, ensuring responsiveness and supporting easy application of seven themes, resulting in a 30% reduction in design inconsistencies. Utilized Ajax and jQuery selectors to access various parts of the DOM, improving page responsiveness by 20%. Played a