Senior Full-Stack Developer · Costa Rica

EstebanRamírez

Twelve years building for the web. React, TypeScript, and Go by day, mentoring and teaching always.

Hola, I’m Esteban.

For twelve years I’ve built software for companies like Hewlett-Packard, TradeStation, and SweetRush, from WordPress sites for global brands to Go microservices moving financial data.

For four of those years I was also a university professor. Teaching Programming I to someone who has never written a line of code teaches you something no framework can: how to make the complex feel simple. I bring that to every team as a mentor, a tech lead, and the person who writes the docs nobody asked for but everyone uses.

What I work with

Bigger name, deeper mastery. Select any technology for the story behind it.

Frontend 16

Backend 10

AI Tools 5

Databases 3

Design 2

Tooling 16

Legacy 10

Technologies I've shipped with, no longer part of my daily stack.

CSS

Expert

Mastery of modern CSS: custom properties, grid, flexbox, animations, and responsive design. No framework required to ship great styles.

  • Grid
  • Flexbox
  • Custom Properties
  • Animations
Documentation ↗

HTML

Expert

The backbone of every web experience. Expert command of semantic HTML5, ARIA roles, structured data, and accessibility best practices.

  • Semantic
  • Accessibility
  • SEO
  • Web Standards
Documentation ↗

JavaScript

Expert

The language of the web. Expert-level knowledge of ES6+ features, async/await patterns, closures, the event loop, and DOM APIs. Every project starts here.

  • ES6+
  • Async/Await
  • DOM
  • Event Loop
Documentation ↗

React

Expert

Primary UI framework. Deep expertise in hooks, context, performance patterns, and component architecture across multiple production applications.

  • Hooks
  • Context
  • JSX
  • Performance
Documentation ↗

SASS

Expert

CSS preprocessor that brings variables, mixins, nesting, and functions. Workhorse of styling at Hangar on dozens of client websites.

  • Mixins
  • Variables
  • Nesting
  • Functions
Documentation ↗

Tailwind CSS

Expert

Utility-first CSS framework that accelerates design system implementation. Used at TradeStation and in recent personal projects, including this portfolio.

  • Utility Classes
  • JIT
  • Design System
  • Responsive
Documentation ↗

TypeScript

Expert

JavaScript with type safety. Used daily at TradeStation and SweetRush to build scalable, maintainable codebases with full IDE support and strict typing.

  • Types
  • Generics
  • Interfaces
  • Decorators
Documentation ↗

Adapt Learning

Advanced

Open-source responsive e-learning framework. Core tool during 4+ years at SweetRush building HTML5 courses with custom components, themes, and extensions.

  • E-learning
  • SCORM
  • Components
  • Theming
Documentation ↗

GSAP

Advanced

The gold standard of web animation. Used at Hangar on client campaign sites, and powering the scroll and reveal animations of this portfolio.

  • Timelines
  • ScrollTrigger
  • Tweens
  • Morphing
Documentation ↗

Next.js

Advanced

Full-stack React framework. Used at TradeStation and SweetRush for server-side rendering, static generation, and API routes in production apps.

  • SSR
  • SSG
  • App Router
  • API Routes
Documentation ↗

Redux

Advanced

Predictable state container for React. Used with Redux Toolkit to manage complex application state across multiple enterprise-grade projects.

  • State Management
  • RTK
  • Thunks
  • Selectors
Documentation ↗

Styled-Components

Advanced

CSS-in-JS solution for component-scoped styling. Used at TradeStation to maintain a large design system with dynamic theming and props-driven styles.

  • CSS-in-JS
  • Theming
  • Dynamic Styles
  • React
Documentation ↗

Vue.js

Advanced

Component-based framework with an elegant reactive system. Used in production projects with Vuex state management and Vue Router for SPA navigation.

  • Composition API
  • Vuex
  • Vue Router
  • SFCs
Documentation ↗

WCAG

Advanced

Web Content Accessibility Guidelines applied at WCAG 2.1 AA level throughout SweetRush projects, including screen reader support and keyboard navigation.

  • A11y
  • ARIA
  • Keyboard Nav
  • Screen Readers
Documentation ↗

Astro

Intermediate

Islands architecture framework for content-driven sites. Used to build this very portfolio, leveraging View Transitions for smooth SPA-like navigation.

  • Islands
  • View Transitions
  • SSG
  • MPA
Documentation ↗

Material-UI

Intermediate

Google's Material Design component library for React. Experience building data-rich interfaces and customizing the theme system for brand alignment.

  • Components
  • Theming
  • MUI v5
  • React
Documentation ↗

Node.js

Advanced

JavaScript runtime for server-side development. Used academically and on select SweetRush projects for build tooling, scripts, and lightweight services.

  • Express
  • REST APIs
  • npm
  • Microservices
Documentation ↗

PHP

Advanced

Server-side scripting language used extensively at Hangar for WordPress themes, custom plugins, and RESTful API integrations.

  • Server-Side
  • WordPress
  • OOP PHP
  • REST APIs
Documentation ↗

REST API

Advanced

Architectural style for distributed systems. Daily experience consuming and designing RESTful APIs across all companies, including financial data feeds at TradeStation.

  • HTTP
  • JSON
  • Authentication
  • OpenAPI
Documentation ↗

WordPress

Advanced

The world's most popular CMS. Built 20+ client sites at Hangar and more at SweetRush, with custom themes, plugins, and performance optimization on Pantheon.

  • Themes
  • Plugins
  • WP-CLI
  • Gutenberg
Documentation ↗

Django

Intermediate

High-level Python web framework. Experience building RESTful APIs with Django REST Framework and admin-driven content management systems.

  • DRF
  • ORM
  • Admin
  • Auth
Documentation ↗

Go

Intermediate

Statically typed, compiled language built for performance and concurrency. Currently using Go at TradeStation for high-throughput financial backend services.

  • Goroutines
  • Channels
  • REST APIs
  • Concurrency
Documentation ↗

Java

Intermediate

Object-oriented language taught for four years at Universidad Castro Carazo across Programming I-III and Data Structures, grounded in classical OOP patterns.

  • OOP
  • JVM
  • Design Patterns
  • Teaching
Documentation ↗

Laravel

Intermediate

Elegant PHP framework with expressive syntax. Experience building MVC applications, RESTful APIs, and using Eloquent ORM for clean data modeling.

  • MVC
  • Eloquent ORM
  • Artisan
  • Blade
Documentation ↗

Python

Intermediate

Versatile scripting language used for data processing, automation tasks, and as the foundation for Django-based web applications.

  • Scripting
  • Data
  • Automation
  • OOP
Documentation ↗

C#

Familiar

Microsoft's statically-typed language. Used at HP for .NET automation tools, and today at TradeStation migrating legacy C# ASP.NET applications to Go and React.

  • OOP
  • .NET
  • ASP.NET
  • LINQ
Documentation ↗

Claude Code

Expert

Anthropic's agentic CLI, in daily use for planning, multi-step implementation, debugging, and reviewing my own work before it ships.

  • Agentic CLI
  • Planning
  • Code Review
Documentation ↗

Cursor

Expert

AI-native code editor and my daily driver. Used for large-scale refactors, multi-file edits, and pairing through unfamiliar codebases at speed.

  • AI Editor
  • Pair Programming
  • Refactoring
Documentation ↗

GitHub Copilot

Expert

In-IDE AI completion and chat, used daily alongside other tools for inline suggestions, quick fixes, and staying in flow without leaving the editor.

  • Autocomplete
  • IDE
  • Chat
Documentation ↗

ChatGPT

Advanced

Go-to for research, debugging rubber-ducking, and drafting, reached for often alongside the coding-specific tools whenever a problem needs a second angle.

  • Research
  • Debugging
  • Writing
Documentation ↗

Gemini

Intermediate

Google's assistant, used occasionally for research and as a second opinion when cross-checking answers from other models.

  • Research
  • Second Opinion
Documentation ↗

MySQL

Advanced

The world's most popular open-source relational database. Used across many web projects for data modeling, query optimization, and schema migrations.

  • Relational
  • Queries
  • Schema Design
  • Indexes
Documentation ↗

PostgreSQL

Intermediate

Powerful open-source object-relational database. Preferred for new projects due to rich features including JSONB, full-text search, and advanced indexing.

  • JSONB
  • Full-Text Search
  • Extensions
  • ACID
Documentation ↗

SQL Server

Intermediate

Microsoft's enterprise relational database. Experience with stored procedures, views, and query optimization in complex enterprise environments.

  • T-SQL
  • Stored Procs
  • Enterprise
  • SSMS
Documentation ↗

Figma

Advanced

The industry-standard design tool. Proficient in design systems, components, auto-layout, and developer handoff. Bridge between design and code.

  • Components
  • Auto-Layout
  • Prototyping
  • Dev Handoff
Documentation ↗

Photoshop

Intermediate

Adobe's image editor. Used at Hangar and SweetRush to optimize assets, retouch images, and create web-ready graphics for client projects.

  • Image Editing
  • Asset Export
  • Compositing
  • Web Graphics
Documentation ↗

Git

Expert

Version control system and daily driver. Expert in branching strategies, rebasing, conflict resolution, and collaborative development workflows.

  • Version Control
  • Branching
  • Rebase
  • Workflows
Documentation ↗

GitHub

Expert

The home of open-source. Expert in pull requests, code review, GitHub Actions, branch protection rules, and team collaboration workflows.

  • Pull Requests
  • Actions
  • Code Review
  • Open Source
Documentation ↗

JSON

Expert

The universal data interchange format. Ubiquitous in API design, configuration files, and data storage, and essential to every modern web application.

  • Data Format
  • APIs
  • Config
  • Serialization
Documentation ↗

npm

Expert

Node.js package manager. Daily tool for managing dependencies, running scripts, and working with the largest software registry in existence.

  • Package Manager
  • Scripts
  • Registry
  • Semver
Documentation ↗

GitLab

Advanced

DevOps platform with integrated CI/CD. Used at multiple companies for merge requests, automated pipelines, and self-hosted repository management.

  • CI/CD
  • Pipelines
  • Merge Requests
  • DevOps
Documentation ↗

JIRA

Advanced

Industry-standard project management for agile teams. Expert use of sprints, backlog grooming, epic tracking, and custom workflow configuration.

  • Agile
  • Sprints
  • Backlog
  • Boards
Documentation ↗

Scrum

Advanced

Agile framework for iterative development. Active participant in daily standups, sprint planning, backlog refinement, retrospectives, and demos.

  • Agile
  • Sprints
  • Standups
  • Retrospectives
Documentation ↗

yarn

Advanced

Fast, reliable JavaScript package manager. Used in projects requiring deterministic installs, workspace support, or faster dependency resolution.

  • Package Manager
  • Workspaces
  • PnP
  • Lock File
Documentation ↗

Bitbucket

Intermediate

Atlassian's Git solution, deeply integrated with JIRA. Experience managing repositories and pull requests in enterprise Atlassian-stack environments.

  • Git
  • Atlassian
  • JIRA Integration
  • Pipelines
Documentation ↗

Docker

Intermediate

Containerization platform for consistent, reproducible environments. Experience with Docker Compose for local dev stacks and container-based deployments.

  • Containers
  • Docker Compose
  • Images
  • DevOps
Documentation ↗

Netlify

Intermediate

Modern web hosting platform for static sites and JAMstack apps. Experience with continuous deployment, form handling, and serverless functions.

  • Hosting
  • CI/CD
  • JAMstack
  • Edge Functions
Documentation ↗

Pantheon

Intermediate

WebOps platform for WordPress and Drupal. Used at Hangar to manage client environments, deployments, performance optimization, and dev/test/live workflows.

  • WebOps
  • WordPress
  • Environments
  • CDN
Documentation ↗

Vercel

Intermediate

Deployment platform optimized for Next.js. Used for zero-config deployments with edge network, preview environments, and serverless functions.

  • Hosting
  • Edge Network
  • Serverless
  • Next.js
Documentation ↗

Vite

Intermediate

Next-generation frontend build tool with lightning-fast HMR. Go-to bundler for modern React and Vue projects, dramatically improving dev experience.

  • Build Tool
  • HMR
  • ESM
  • Rollup
Documentation ↗

Webpack

Intermediate

The classic JavaScript module bundler. Experience configuring loaders, plugins, code splitting, and custom build pipelines for enterprise applications.

  • Bundler
  • Loaders
  • Code Splitting
  • Optimization
Documentation ↗

Hubspot

Familiar

CRM and marketing platform. Experience building custom HubSpot CMS templates, modules, and integrating with marketing automation workflows using HubL.

  • CMS
  • CRM
  • Templates
  • HubL
Documentation ↗

Bootstrap

Advanced

Classic CSS framework for rapid UI development. Solid experience building responsive layouts and customizing the component library for client projects.

  • Grid System
  • Components
  • Utilities
  • Responsive
Documentation ↗

Gulp.js

Advanced

Streaming build automation toolkit. Primary build tool at Hangar for compiling SASS, minifying assets, and automating development workflows.

  • Task Runner
  • Streams
  • Automation
  • Build Pipelines
Documentation ↗

jQuery

Advanced

The library that defined an era of the web. Used extensively at Hangar and SweetRush for DOM manipulation, animations, and plugins on client sites.

  • DOM
  • Ajax
  • Plugins
  • Animations
Documentation ↗

Less

Intermediate

CSS preprocessor from the pre-SASS-consolidation era. Used at SweetRush maintaining and extending Less codebases on legacy client projects.

  • Preprocessor
  • Variables
  • Nesting
  • Legacy
Documentation ↗

Sketch

Intermediate

Vector design tool that was the industry standard before Figma. Experience translating Sketch files into pixel-perfect web implementations.

  • Vector
  • Symbols
  • Plugins
  • Export
Documentation ↗

Visual Basic

Intermediate

VB.NET and VBA from the HP years: Excel macro automation and .NET reporting apps that streamlined sales and inventory workflows.

  • VB.NET
  • VBA
  • Excel Macros
  • .NET
Documentation ↗

Zeplin

Intermediate

Design-to-development handoff tool. Used to extract accurate spacing, colors, and assets from design files for pixel-perfect implementations.

  • Handoff
  • Specs
  • Assets
  • Collaboration
Documentation ↗

Drupal

Familiar

Enterprise open-source CMS. Experience at Hangar maintaining and extending client Drupal sites hosted on Pantheon.

  • CMS
  • Modules
  • Theming
  • Pantheon
Documentation ↗

GruntJS

Familiar

JavaScript task runner used in legacy project configurations for automating repetitive tasks like minification and CSS compilation.

  • Task Runner
  • Automation
  • Legacy
  • Config-Based
Documentation ↗

SVN

Familiar

Centralized version control system. Used at SweetRush on legacy client projects that had not yet migrated to Git-based workflows.

  • Version Control
  • Centralized
  • Legacy
  • Commits
Documentation ↗

Where I’ve been

  1. September 2024 — Present

    TradeStation

    Senior Software Engineer

    • Enhance software functionality by identifying and resolving complex technical issues.
    • Mentor junior developers, fostering professional growth, and enhancing team productivity.
    • Develop scalable applications using agile methodologies for timely project delivery.
    • Contribute to the migration of legacy C# ASP.NET applications to modern technologies, including Go and React, improving performance, maintainability, and scalability.
    • React
    • TypeScript
    • Go
    • C#
    • ASP.NET
    • Git
    • Agile
  2. October 2019 — June 2024

    SweetRush

    Tech Lead / Web Engineer

    • Developed responsive, user-friendly websites, applying JavaScript, custom styling, and HTML best practices.
    • Mentored junior developers through regular one-on-one meetings, providing guidance on best practices, coding standards, and career growth opportunities.
    • Managed multiple projects simultaneously while maintaining strict deadlines and high-quality standards.
    • Developed HTML5 e-learning solutions using React and Adapt Learning frameworks.
    • React
    • JavaScript
    • HTML5
    • CSS3
    • SASS
    • Wordpress
    • Adapt Learning
    • Git
    • Jira
    • Scrum
  3. September 2019 — December 2023

    Universidad Castro Carazo

    Professor

    • Led courses such as Programming I, II, and III, Data Structures, Systems Analysis and Design, and Computer Architecture.
    • Used different learning modes and technologies to engage students in achieving learning outcomes.
    • Increased course relevance by incorporating real-world examples and case studies into lesson plans.
    • JavaScript
    • React
    • Vue.js
    • Java
    • PHP
    • Laravel
    • C++
    • Git
    • Arduino
  4. April 2015 — September 2019

    Critical Mass LATAM (formerly Hangar)

    Intermediate Web Developer

    • Developed front-end web solutions, including responsive design, JavaScript functionality, styling, templating, and building HTML structures from scratch, following best practices.
    • Served as a Content Entry Specialist and Developer for the Nissan USA team.
    • Front-end Developer for the Ketchum team.
    • HTML5
    • CSS3
    • SASS
    • JavaScript
    • jQuery
    • GSAP
    • Wordpress
    • Bootstrap
    • Webpack
    • Gulp
    • Git
  5. January 2013 — March 2015

    Hewlett-Packard

    Reporting Analyst / Developer

    • Developed Excel macros and .NET applications for process automation.
    • Created, managed, and analyzed sales and inventory reports for internal and external partners.
    • VB.net
    • C#
    • SQL Server
    • Excel

In their words

Any task assigned to Esteban would be executed with precision and delivered on time, always meeting the highest standards of quality. Project teams frequently requested his involvement, knowing that Esteban's presence would ensure the success of their initiatives.

Michael (Misha) MilshteinDirect manager at SweetRush · 2024

He also is a great teammate, having taught many developers at SweetRush the art and science of Javascript coding. He was the lead software engineer on a variety of SweetRush projects, and was instrumental in getting them built right and delivered successfully.

John CleaveSenior colleague at SweetRush · 2024
Read them on LinkedIn ↗

Selected work

Legacy Migration Platform

2024 · In progress

Migrating a large-scale C# monolith to a Go + React microservices architecture at TradeStation. Includes API gateway design, incremental rollout strategy, and zero-downtime deployments.

  • Reduced API latency by 40% on migrated services
  • Designed incremental migration strategy with feature flags
  • Built shared component library used across 3 teams
  • Go
  • React
  • TypeScript
  • Docker
  • PostgreSQL

Personal Portfolio

2026 · Live

A bilingual (EN/ES) one-page portfolio and résumé built with Astro, GSAP ScrollTrigger, and Lenis smooth scroll. The hero runs a custom canvas 2D scene with a typing terminal, growing circuit traces, and particle text. Includes a dual light/dark theme and WCAG AA accessibility with a full reduced-motion fallback.

  • Canvas 2D hero scene with a typing terminal, growing circuit traces, and particle text, no WebGL or libraries involved
  • GSAP scroll choreography with a complete reduced-motion fallback
  • Bilingual EN/ES with a dual light/dark OKLCH theme system

Education

  • April 2018

    Bachelor's Degree · Business Computing

    Universidad De Costa Rica — San Ramón, Costa Rica

    Assistant Professor in several courses, such as Programming I & II.

  • December 2015

    English Now · Language Certificate

    Centro Cultural Costarricense Norteamericano — San José, Costa Rica

    Intermediate language skills, writing, and speaking more than 85%.

Say hello

Whether you’re hiring, building something, or just want to talk shop, my inbox is open.