César Leiva
Full Stack Developer
Business Software · Dashboards · Integrations · SaaS
About Me
Hello, I'm César Leiva, a Chilean living in Portugal. I build business software that turns manual processes into efficient tools for real companies.
frontend
backend
database
tools
My Services
I build business software end to end: dashboards, document generation, API integrations and SaaS platforms. From concept to deployment — with clean code and real results.
Frontend Development
Modern, responsive web applications and business dashboards built with React, Next.js, and TypeScript. Focus on user experience, performance optimization, and clean, maintainable code.
Technologies
Key Features
- Responsive Design
- Performance Optimization
- TypeScript Integration
- Modern UI/UX
Backend Development
Scalable server-side applications with Node.js and Express.js. Secure authentication, database design, and API development.
Technologies
Key Features
- RESTful APIs
- Database Design
- Authentication & Security
- Scalable Architecture
Full Stack Solutions
End-to-end web application development from database design to deployment. Specialized in TypeScript ecosystem and modern development practices.
Technologies
Key Features
- End-to-end Development
- Database Integration
- API Development
- Production Deployment
Database Design
Efficient database modeling and optimization using MySQL, MongoDB, and Prisma ORM. Focus on performance and scalability.
Technologies
Key Features
- Schema Design
- Query Optimization
- Data Migration
- Performance Tuning
API Integration
Seamless integration with third-party services: payment systems, cloud storage, and communication APIs (WhatsApp, Google Calendar), and more.
Technologies
Key Features
- Payment Integration
- Cloud Services
- Communication APIs
- Custom Integrations
Deployment & DevOps
Production-ready deployment solutions using modern platforms and containerization. Focus on reliability and scalability.
Technologies
Key Features
- Production Deployment
- Container Management
- Version Control
- Server Configuration
My Process
Discovery
Understanding your needs, goals, and project requirements through detailed consultation.
Planning
Creating a comprehensive project plan with timelines, milestones, and technical specifications.
Development
Building your solution using best practices, clean code, and regular progress updates.
Delivery
Testing, deployment, and ongoing support to ensure your project succeeds long-term.
Ready to Start Your Project?
Let's discuss your ideas and create something amazing together. I'm here to help you turn your vision into reality.
My Projects
Here are some of the projects I've worked on. Each one represents a unique challenge and learning experience in my development journey.
CO2 Emissions Calculator - CITEVE
CITEVE needed to track carbon emissions across the textile industry in the Minho region, replacing manual processes with a centralized system.
Carbon footprint calculation system for industrial emissions with role-based access control, PDF reports with charts, and comprehensive emission tracking.
Impact
- Serving 15+ companies in the textile sector (Minho, Portugal)
- Official PDF reports with embedded charts
- Role-based access control for different teams
Budget Management System - Home-Tec
Home-Tec’s sales team needed to create detailed budgets faster, placing products inside customizable structures (houses/rooms) and controlling access per role.
Budget system with customizable PDF generation, product placement in modifiable structures (houses/rooms), and multi-level user roles for sales teams.
Impact
- 3,000+ products managed in the catalog
- Customizable PDF budgets with product placement in houses/rooms
- Role-based access for the commercial team
Municipal Agenda - Pegadas Guimarães
The municipality needed a single source of truth for activities, synced with Google Calendar and with schedule blocking to avoid double bookings.
Activity management system connected to Google Calendar for Guimarães Municipality, featuring team management, requests, external events, and schedule blocking.
Impact
- 100+ events and 30+ activity types managed
- Real-time sync with Google Calendar and schedule blocking
- Public access for end users without sessions
File Management SaaS - FlyFiles
FlyFiles needed a multi-tenant file platform where each client gets its own structure, secure sharing links with expiration, and permanent storage.
SaaS platform for file administration with expirable sharing links, permanent file management with client access, and customizable file structure per client.
Impact
- 2-3 GB of uploads shared every day
- Multi-tenant: one main client with subclients
- AWS / Cloudflare R2 object storage and shared sessions
Kova - Team Management SaaS
Teams juggle tasks, HR requests and calendar events across separate tools, and companies need to track their vehicle fleet. Kova centralizes both in one platform.
Teamwork-style SaaS for tasks, personnel and vehicle fleet management, HR requests, vacations and calendar events, with a Microsoft Project-like hierarchy and document management.
Impact
- Clients → projects → lists → tasks → subtasks hierarchy (Microsoft Project style)
- Personnel management: HR requests, vacations and calendar events
- Vehicle fleet tracking: who drives, how much and where vehicles moved
- Document management with Google Drive / Dropbox integration (R2 containers planned)
Satisfaction Surveys - Vitória SC
Vitória SC needed to measure fan and member satisfaction across different areas of the club with a flexible survey system.
Satisfaction survey platform for Vitória SC with multiple form types and thousands of collected responses.
Impact
- 4 different form types
- 4,000+ survey responses collected
Member Renumeration - Vitória SC
The club needed to renumber and update its full membership records in an organized, auditable way.
System to renumber and update membership records for Vitória SC, processing the entire club membership base.
Impact
- 11,000+ club members processed
Member Management - Vitória SC
The club needed a modern member registration platform connected directly to its sports management system (SMA) to keep member data in sync.
Member management platform for Vitória SC with direct integration to the club’s sports management system (SMA / Smart Move API).
Impact
- 1,400+ members registered on the platform
- Direct integration with SMA (Smart Move API) sports management
Corrida dos Galos - Gil Vicente FC
Gil Vicente FC needed a lightweight, public site to inform attendees about the Corrida dos Galos event.
Informational website for the Corrida dos Galos event by Gil Vicente FC.
Impact
- Fast, mobile-friendly event information
- Public event details in a lightweight site
WhatsApp Business Management
Experimented with managing multiple WhatsApp accounts from one place: marketing campaigns, automated replies, and client records.
Multi-account WhatsApp Business management system using Cloud API for marketing messaging, automated responses, client management, and template administration.
Impact
- Multi-account management via WhatsApp Cloud API
- Marketing messaging, automated responses and template management
2FA Authenticator Mobile App
Experimented with a self-hosted way to generate two-factor authentication codes from a phone across multiple systems.
Mobile application for two-factor authentication connections, providing secure authentication for various systems and platforms.
Impact
- Secure 2FA codes (TOTP) generated on mobile
- Multiple accounts and platforms supported, offline code generation
Interested in working together? Let's create something amazing!
Trusted by Industry Leaders
I've had the privilege to work with some of the most innovative companies in the tech industry, delivering high-quality solutions and exceeding expectations.
What Clients Say
César built our CO2 emission calculator from the ground up. It handles the complexity of textile industry data and generates the official PDF reports our 20 member companies rely on. Delivered on time and with excellent communication throughout.
The budget system changed how our sales team works. With more than 3,000 products and customizable PDF quotes, budgets that used to take hours now take minutes. The role-based access is exactly what we needed.
Our activity agenda integrates perfectly with Google Calendar. We manage over 100 events across 30+ activity types, block schedules to avoid conflicts, and citizens access the info without any friction. César understood our municipal workflows from day one.
Get In Touch
Ready to bring your ideas to life? Let's discuss your project and create something amazing together. I'm always excited to work on new challenges.