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I will develop existing saas, add next js react features, node js API and postgresql
Lena Paul
About this gig
Your SaaS is already built, but you need the right developer to move it forward without starting again from scratch.
I develop and improve existing SaaS applications using Next.js, React, Node.js, and PostgreSQL. Whether you need a new feature, dashboard, backend workflow, database update, API integration, or unfinished functionality completed, I can work within your current product and codebase.
SERVICES INCLUDE:
- New SaaS features and functionality
- Next.js and React UI development
- Dashboard and portal development
- Node.js backend development
- PostgreSQL database updates
- REST API development and integration
- Authentication and user roles
- Business workflow implementation
- Third-party API integrations
- Existing feature improvements
- Responsive UI implementation
- Bug fixing and debugging
- Testing and deployment support
Ideal for SaaS founders, startups, agencies, and businesses with an existing application.
Send your repository details, feature requirements, screenshots, or Figma before ordering. I'll review the scope and recommend the right solution.
Get to know Lena Paul
Lena Paul
Web Developer I WordPress, SaaS and Custom Web Applications
- FromGermany
- Member sinceAug 2026
Languages
German, English, Italian
I build practical web solutions for businesses, startups, and agencies, from WordPress projects and dynamic listing systems to custom SaaS applications and internal dashboards. I work with React, Next.js, Node.js, PostgreSQL, WordPress, JetEngine, Crocoblock and APIs to create, improve, and troubleshoot web systems. I focus on clean functionality, responsive interfaces, reliable integrations, and solutions that are easy to maintain. If you already have a project that needs development, new features, or fixing, I’m happy to take a look.
FAQ
Can you work with an existing SaaS codebase?
Yes. This Gig is specifically designed for existing SaaS applications that need additional features, improvements, integrations, or continued development.
Will you review my existing code before starting?
Yes. For larger updates, I recommend reviewing the relevant code structure and requirements first so the scope can be defined properly.
Can you complete an unfinished SaaS project?
Yes, depending on its current condition. Send details of what has already been developed and what remains unfinished so I can assess the required work.
Can you add new features without rebuilding my application?
Yes, when the existing architecture supports them. I will work within the current codebase where practical rather than unnecessarily rebuilding the product.
Can you improve my existing Next.js or React dashboard?
Yes. I can add screens, components, workflows, API-connected data, tables, forms, dashboards, and other agreed functionality.
Can you modify my PostgreSQL database?
Yes. I can work on database schemas, tables, relationships, queries, and feature-related database changes based on the project requirements.
Can you integrate third-party APIs into my existing SaaS?
Yes. I can integrate suitable external APIs, webhooks, services, and data workflows where API access and documentation are available.
Can you fix bugs while adding new functionality?
Yes. Bugs directly related to the agreed feature can be addressed. Larger unrelated issues should be scoped separately.
