Ronaldo Sergio Jara Full Stack Developer

+4 years delivering digital products in EdTech, FinTech & Healthcare — from design to production.

Experience

  1. Full Stack Developer | LearnAla

    Sole technical owner of the LearnAla LMS — a SaaS EdTech platform serving active users in production. Full stack across React, Redux and Django, working directly with the CEO.

    Show details
    • Reduced production errors by 96% — from 3,200 to 109 incidents in Sentry — improving platform stability and reliability.
    • Optimized critical API endpoints by resolving N+1 queries and redundant calls, cutting database load by 50–95%.
    • Designed and built an external activity tracking module, enabling teachers and admins to integrate off-platform learning into the LMS.

  2. Frontend Developer | Flujolink

    Improved frontend performance, stability, and code quality for a growing FinTech platform, working with React, TypeScript, TailwindCSS, and React Query.

    Show details
    • Cut CRM module load time from ~6s to ~2s by implementing virtual scroll, prefetching, and request caching — eliminating UI blocking on high-volume components.
    • Fixed systemic visual inconsistencies caused by absent design tokens and reusable components, aligning the UI with original designs.
    • Served as the technical bridge between design and backend teams, translating visual requirements into coherent frontend implementations.

  3. Founding Full Stack Developer | Nawa Method

    Founding developer of an AI-powered mental wellness app, built from scratch — frontend in React Native, backend in NestJS, with OpenAI API integration.

    Show details
    • Built 3 of the 4 core platform modules — gamified learning paths, admin dashboard, and account settings — including Figma design and full implementation in React Native and React.
    • Integrated the OpenAI API to deliver personalized AI coaching and dynamic content adapted to each user's progress — the product's core feature.
    • Designed the frontend and backend architecture from zero, making key technical decisions on stack, structure, and scalability with NestJS and PostgreSQL.

  4. Frontend Developer | LearnAla

    Owned UX/UI and frontend development for LearnAla LMS and Classbot AI, in a 7-person EdTech startup serving underserved communities with AI-powered educational tools.

    Show details
    • Led the frontend development of Classbot AI — a platform letting teachers create per-classroom AI chatbots powered by the OpenAI API.
    • Built key LMS features including an academic scheduling system and improvements to the rich text editor, one of the platform's most-used components.
    • Defined team-wide UX/UI standards: reusable components, design tokens, and user flows in Figma for both products.

  5. Frontend Developer | DAWG Motors

    Optimized the performance of a web monitoring dashboard for an electric motor startup, working with React and Material UI.

    Show details
    • Cut initial load time from ~13s to ~5s using code splitting and render optimization — a 60%+ improvement in user experience.
    • Documented bugs and technical debt, identifying critical areas of improvement for future developers.

About me

Full Stack Developer with 4+ years building products across EdTech, FinTech and Healthcare, working as the lead developer alongside CEOs and CTOs. My focus: frontend development and UX/UI design.

I bring both sides to every project: the technical depth to build it right, and the design eye to make it work for real users. Open to remote Full Stack or Frontend roles.

Personal Projects

URL Shortener
Code Preview

URL Shortener

Simple and secure URL shortening

  • NextJS
  • Tailwind CSS
  • ReactJS
  • TypeScript
  • Drizzel

A modern URL shortener that prioritises user experience and a clean design. Features a minimalist interface and optimised performance powered by modern React and Next.js patterns.

Mock Shop API
Code Preview

Mock Shop API

Production-ready e-commerce API

  • NestJS
  • GraphQL
  • Prisma
  • TypeScript
  • OpenTelemetry

A REST + GraphQL API simulating a modern e-commerce backend. Demonstrates advanced patterns: dual transport with a shared service layer, N+1 prevention with DataLoader, and more.

Lite Observer
Code

Lite Observer

Local OpenTelemetry trace explorer

  • Fastify
  • ReactJS
  • Tailwind CSS
  • TypeScript
  • OpenTelemetry

A lightweight OpenTelemetry trace explorer designed for local development. Point your OTLP exporter at it, open the UI, and understand what your services are doing — without spinning up a full observability stack.

Got a project in mind?

Whether it's a new product, a feature that needs building, or just an idea you want to think through — reach out. I respond to every message.

Send me an email
Download CV