<Keyner Perez/>



Fullstack Developer

Web & Mobile

keyner, focused programmer wearing a hoodie and headset, working on a laptop.


Available for work

6+

Projects

Shipped

2+

Years

Experience

10+

APIs

Integrated

100%

Focus

Product Quality

Keyner Pérez

Aboutme

I am a product-oriented fullstack developer with hands-on experience delivering production web and mobile platforms. Beyond frontend and backend development, I integrate applied AI capabilities into real workflows and take ownership of Linux VPS deployments (Docker, PM2, Nginx), continuous maintenance, and technical evolution of applications.

Design with intention, develop with discipline

MultipleTech Stack

I work across multiple technologies and frameworks to build scalable, real-time and production-ready systems.

Development & Systems

Building scalable web and mobile applications with real-time capabilities, strong backend integration, and production-ready architecture.

UX & Product Thinking

Focused on creating intuitive, efficient and user-centered experiences, reducing friction and improving workflows.

Open to Collaboration

Available for freelance projects, product development or team collaboration. Open to building impactful solutions.

TechStack

Core capabilities organized by domain, focused on production delivery and maintainable architecture.

Programming Languages & Frontend→

Backend & Databases→

Infrastructure & AI→

SelectedWorks

A collection of projects I've built and designed

HealthApp analytics dashboard
SigrisOne web module view

SigrisOne Web

Production healthcare platform with web and mobile modules for daily operations, patient workflows, and health metrics visualization.

AngularIonicFastAPINode.jsMongoDB
SellerCall call dashboard
SellerCall login screen

SellerCall

AI-powered sales call automation system with real-time communication flows, operator tracking, and performance views.

Blazor.NETSignalRTwilioSQL

Mobile Projects

SigrisOne App

Production healthcare platform with web and mobile modules for daily operations, patient workflows, and health metrics visualization.

IonicFastAPIPostgreSQLAndroid StudioXcode
RonaldCoach home screen
RonaldCoach player screen

RonaldCoach

Subscription-based training mobile app focused on content playback and a clean portrait-first user experience.

VueCloudflareFastAPIVideo StreamingPayments

Experiences

Real-world experience building production products, integrating applied AI, and running infrastructure with technical ownership.

SaludFamiliar

Fullstack Developer

2024 - Present

Mode: Contractor

Building and evolving a production healthcare platform used in daily clinical operations.

Impact: unified clinical, administrative, and mobile workflows into one platform, reducing operational friction for care teams.

  • Implemented Angular modules for clinical records, scheduling, and reporting with TypeScript/JavaScript
  • Designed and maintained FastAPI and Node.js APIs with JWT auth and role-based permissions
  • Built Ionic mobile functionality and delivered Android/iOS release cycles based on business needs
  • Modeled PostgreSQL/MySQL/MongoDB persistence for clinical traceability, forms, and documents
  • Automated support and operational analysis tasks with Python scripts (Pandas and NumPy)
AngularTypeScriptJavaScriptIonicFastAPINode.jsPostgreSQLMySQLMongoDBPythonPandasNumPy

SellerCall (AI Call System)

Fullstack Developer

2025 - Present

Mode: Freelance

AI-enabled sales call automation platform with real-time events and dynamic responses.

Impact: enabled live visibility of calls and sales actions to improve response times and follow-up quality.

  • Built .NET backend services and Blazor dashboards in C# for daily campaign operations
  • Implemented SignalR and WebSockets for instant synchronization of statuses, queues, and metrics
  • Integrated Ultravox for voice processing and context-aware dynamic responses
  • Connected Twilio (voice/WhatsApp/SMS) and designed behavior-based intelligent triggers
  • Published REST APIs for external integrations and workflow automation
BlazorC#.NETSignalRWebSocketsTwilioUltravoxREST APIsSQL

Video Subscription Platform (RonaldCoach)

Fullstack Developer

2025 - Present

Mode: Personal Project

Video subscription product with secure content delivery, payment logic, and protected access.

Impact: moved from prototype to stable operation with subscription validation and ongoing premium content delivery.

  • Defined React frontend architecture and FastAPI business services for playback and memberships
  • Integrated ePayco and subscription validation rules to protect premium content
  • Implemented Cloudflare-based protection and distribution for static and video resources
  • Designed REST endpoints and JWT session management for web/mobile consumption
  • Configured SQL-based operational logging for support and incident diagnosis
ReactFastAPICloudflareJWTREST APIsSQL

Dialnet (E-commerce Frontend)

Frontend Developer

2025

Mode: Freelance

E-commerce frontend for art sales focused on purchase UX, reliability, and performance.

Impact: optimized checkout and catalog navigation, reducing friction in high-intent purchase flows.

  • Built React + TypeScript UI for catalog, cart, and checkout journeys
  • Integrated payment gateway and validation rules to reduce transaction failures
  • Used JavaScript and reusable component patterns to improve perceived performance
  • Maintained legacy PHP integrations without disrupting production continuity
  • Implemented Firebase-based authentication/notification modules in specific flows
ReactTypeScriptJavaScriptPHPFirebaseREST APIs

AI & Prediction Apps

Fullstack Developer

2024 - Present

Mode: Personal Project + Applied R&D

Building products that integrate AI capabilities into real workflows, without positioning as ML research.

Impact: turned ideas into working assistants that react to events, voice, and user context inside real products.

  • Integrated conversational chat inside a project planner with stage-aware responses
  • Implemented intelligent triggers reacting to user behavior and system events
  • Orchestrated OpenAI APIs, HuggingFace services, and local models with Ollama
  • Processed voice and text for real-time assistance and automation flows
  • Used Python with Pandas/NumPy for data preparation and automation rules
OpenAI APIsHuggingFaceOllamaUltravoxPythonPandasNumPyFastAPIAutomation

Deploy & Operations (Linux VPS)

Fullstack + Applied DevOps

2024 - Present

Mode: Freelance / Personal Project

Hands-on deployment and maintenance operations for production web apps and APIs.

Impact: improved service continuity with repeatable deployments, recovery procedures, and lower downtime risk.

  • Deployed Node.js and FastAPI services on Linux VPS with Docker and PM2 via ecosystem.config
  • Configured Nginx as reverse proxy, TLS routing, and multi-app host setup
  • Handled update cycles with git fetch/pull, backups, restores, and controlled service restarts
  • Managed deliverables through SFTP, Linux permissions, and per-project environment variables
  • Maintained continuous publication and baseline observability for post-release support
VPSLinuxDockerPM2ecosystem.configNginxNode.jsFastAPISFTPGit

Do you like mywork?

Have a project in mind, a question, or just want to say hello?
Feel free to reach out, I'm always open to connect!

Salary expectation (negotiable): COP 3,500,000–4,500,000 depending on responsibilities and project scope.

0 / 300

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Copyright © 2025-Keyner Pérez
All Rights Reserved