Einar Montalvo

Crafting exceptional digital experiences with clean code and thoughtful design

Available for projects
Get To Know Me

About Me

Crafting digital experiences with passion, precision, and purpose

👋Hello, I'm Einar Montalvo

A passionate Full Stack Developer and  AI enthusiast with 10+ years of experience crafting digital experiences that users love.

I specialize in building scalable web and mobile applications using React, Next.js, TypeScript, and modern development technologies. I thrive on turning complex problems into elegant solutions that users love.

Beyond work, I love exploring emerging technologies, contributing to open-source projects, and mentoring aspiring developers. I believe in continuous learning and staying at the forefront of technological innovation.

Core Technologies

AI IntegrationLeadershipAgileReactNext.jsTypeScriptNode.jsPythonAWSUI/UX Design

Software Engineer

Yellow Systems

2023 — Present

Delivering AI-powered high-quality projects across diverse domains, specializing in web applications, API development, and cloud integrations.

Leadership, Agile, AI Integration

Senior Web developer

FoxyAI

2022 — 2023

Built AI-powered property valuation interfaces processing millions of images, implementing computer vision workflows and interactive dashboards for insights

Real Estate IT Specialist

Let's Connect

montalvoeinar669@gmail.com
+1 (360) 268-8850
Seattle, WA

Achievements

Start-up veteran
Expert in AI Integration
10+ Projects Delivered

Available for Hire

Open to New Opportunities
Open to Relocation
Remote & On-site Available
Tech Arsenal

Technology Stack

Technologies I use to bring ideas to life

Backend

Node.js

Expert
8 years exp

Python

Expert
10 years exp

Nest

Expert
4 years exp

Express

Expert
8 years exp

FastAPI

Expert
4 years exp

Django

Expert
8 years exp

GraphQL

Expert
6 years exp

Socket.io

Expert
5 years exp

OAuth2

Expert
5 years exp

Frontend

React

Expert
8 years exp

Vue

Expert
6 years exp

Next.js

Expert
5 years exp

Redux

Expert
7 years exp

TypeScript

Expert
8 years exp

JavaScript

Expert
12 years exp

Tailwind CSS

Expert
4 years exp

Material UI

Expert
8 years exp

D3.js

Expert
5 years exp

SVG

Expert
10 years exp

Tanstack Query

Expert
3 years exp

Flutter

Intermediate
2 years exp

Database

PostgreSQL

Expert
4 years exp

MongoDB

Expert
6 years exp

MySQL

Expert
10 years exp

Redis

Expert
5 years exp

Prisma

Expert
4 years exp

ELK

Expert
3 years exp

Cloud & DevOps

AWS

Expert
8 years exp

GCP

Expert
4 years exp

Firebase

Expert
6 years exp

Kubernetes

Intermediate
3 years exp

Docker

Expert
6 years exp

Git

Expert
8 years exp

AI & Integration

OpenAI

Expert
3 years exp

LangChain

Expert
2 years exp

Vercel AI SDK

Expert
1 year exp

Stripe

Expert
2 years exp

Vector Database

Expert
2 years exp

MCP

Intermediate
1 year exp
Education Stories

Degrees Received

Master's Degree
"Pursued advanced studies in Computer Science with focus on machine learning and software engineering"
4.0
The University of Tokyo
Professional Journey

Experience

My professional journey and the impact I've made across different domains

October 2023 — July 2025

Senior Full Stack Engineer

Yellow Systems

Led frontend development for AI-powered search engine, enhancing the conversational interface and real-time answer generation system that serves millions of users seeking accurate, cited information.

Key Achievements

Architected real-time answer streaming interface using React and Server-Sent Events, reducing perceived latency by 60% and enabling progressive answer rendering with citation highlighting
Built advanced citation system with inline source previews, domain verification badges, and credibility scoring, improving user trust metrics by 35%
Developed interactive follow-up question suggestions using context-aware AI, increasing user engagement and session depth by 45%
Implemented conversation threading and search history features with optimistic UI updates and offline support using IndexedDB and service workers
Created specialized search modes (Academic, Writing, Code) with custom UI components and tailored prompt engineering, adopted by 2M+ users
Optimized search result rendering with virtualization and lazy loading, handling 10K+ token responses while maintaining 60fps scrolling performance
Led migration to Next.js 15 App Router with streaming SSR, improving Core Web Vitals scores by 40% and SEO visibility for shared answers

Technologies & Skills

ReactNext.js 15TypeScriptServer-Sent EventsTanStack QueryTailwind CSSFramer MotionIndexedDBService WorkersPythonFastAPIRedisPostgreSQLOpenAI APIWeb Vitals
September 2022 — October 2023

Full Stack Developer

FoxyAI

Built AI-powered property intelligence platform using computer vision and ML to analyze property images, detect damage, and generate comprehensive reports for real estate professionals processing 10K+ properties daily.

Key Achievements

Built AI-powered property intelligence platform using computer vision and ML to analyze property images, detect damage, and generate comprehensive PDF reports for real estate professionals
Integrated Zillow API with custom ML models to create automated property assessment tool processing 10K+ properties daily with 95% accuracy
Deployed containerized microservices on AWS ECS with auto-scaling policies, handling 10x traffic spikes during peak real estate seasons without performance degradation
Implemented PDF generation pipeline using Node.js and Puppeteer, creating customizable reports with charts, images, and AI-generated insights
Set up monitoring and alerting using DataDog APM, Sentry for error tracking, and custom CloudWatch dashboards, reducing MTTR from hours to minutes
Established testing pyramid with unit tests (Jest), integration tests (Supertest), and E2E tests (Cypress), achieving 80% code coverage and catching 95% of bugs pre-production

Technologies & Skills

ReactNode.jsComputer VisionML ModelsAWS ECSDockerPuppeteerDataDogSentryCloudWatchJestCypressSupertestPostgreSQL
February 2017 — September 2022

Senior Frontend Engineer

Asian Logic

Led migration of legacy betting platforms to modern architecture, supporting millions of concurrent users across multiple brands (Dafabet, Nextbet, Zedbet) with real-time sports betting capabilities.

Key Achievements

Led migration of legacy Backbone.js betting platform to Next.js with SSR, improving performance by 80% and supporting millions of concurrent users during major sporting events
Architected multi-brand theming system supporting Dafabet, Nextbet, and Zedbet from single codebase, reducing deployment time by 90% using 'build once, deploy many' approach
Built real-time sports betting interface handling 500K+ odds updates/minute using WebSocket connections and efficient React state management
Implemented blue-green deployment strategy with NGINX load balancers and health checks, achieving zero-downtime deployments during critical betting events
Optimized performance using CDN and reverse proxy caching (NGINX, Varnish), achieving sub-second load times and 99.9% uptime during peak traffic
Created load testing framework using K6 and JMeter, simulating 100K concurrent users to identify bottlenecks and optimize infrastructure for major sporting events
Established feature flag system using LaunchDarkly for gradual rollouts and A/B testing, enabling safe experimentation without impacting user experience

Technologies & Skills

ReactNext.jsBackbone.jsWebSocketNGINXVarnishCDNLaunchDarklyK6JMeterNode.jsRedisBlue-Green Deployment
October 2015 — February 2017

Frontend Engineer

Meta

Contributed to Facebook Profile redesign serving 2B+ users, transitioning from Timeline to single-column layout while building performant UI components for News Feed with advanced optimization strategies.

Key Achievements

Contributed to Facebook Profile redesign serving 2B+ users, transitioning from Timeline to single-column layout using React and custom framework
Built performant UI components for News Feed using React, achieving 60fps scrolling with virtualization and intelligent rendering strategies
Developed A/B testing framework for rapid experimentation, enabling data-driven decisions that improved user engagement by 25%
Implemented automated performance testing using Lighthouse CI and custom metrics, blocking deployments that degraded Core Web Vitals below thresholds
Participated in on-call rotation managing production incidents, improving system reliability through runbooks, monitoring dashboards, and post-mortem processes
Contributed to internal testing tools enabling engineers to write visual regression tests, reducing UI bugs in production by 60%

Technologies & Skills

ReactCustom FrameworkA/B TestingLighthouse CIPerformance OptimizationVisual Regression TestingJavaScriptCSSInternal Tools
10+
Years Experience
10+
Projects Completed
90%
Success Rate
Portfolio Showcase

Featured Projects

Discover my latest work in web development, AI integration, and digital innovation

AI/ML Platform
Live6 months

Athina.ai

Enterprise LLM Development & Monitoring Platform

A production-grade platform enabling teams to build, test, and monitor LLM-powered applications at scale. Serving 50+ enterprise clients with comprehensive tools for prompt engineering, multi-model orchestration, and real-time performance monitoring across 100M+ daily API calls.

Live Demo

Key Features

  • Multi-model orchestration supporting OpenAI GPT-4, Claude, PaLM, Llama, and Mistral
  • Collaborative prompt engineering workspace with version control and A/B testing
  • Automated evaluation framework with hallucination detection and quality scoring
  • Real-time monitoring dashboard tracking token usage, latency, and model drift
  • Intelligent routing based on cost, latency, and performance requirements
  • Streaming response handling for real-time LLM interactions
  • Custom metrics for semantic similarity and response quality analysis
  • Event-driven architecture for processing large-scale LLM interactions

Deliverables

  • Full-stack web application deployed on AWS infrastructure
  • Multi-model LLM orchestration layer with intelligent routing
  • Prompt engineering workspace with collaborative editing
  • Automated testing and evaluation framework
  • Real-time analytics and monitoring dashboard
  • RESTful and GraphQL APIs for LLM provider integrations
  • Comprehensive documentation and open-source utilities

Technology Stack

Next.js 15React 19TypeScriptTailwind CSSNode.jsPython FastAPIPostgreSQLMongoDBRedisApache KafkaAWS ECSLambdaD3.jsLangChainWebSocket
IoT/Robotics Platform
Live8 months

Serve Robotics

Real-Time Robot Fleet Management Platform

A comprehensive robotics tracking and management platform that enables real-time monitoring of autonomous service robots. Features advanced mapping capabilities for tracking robot movements, status monitoring, and fleet optimization across multiple deployment locations.

Live Demo

Key Features

  • Real-time robot tracking with live position updates on interactive maps
  • Fleet status monitoring with health metrics and battery levels
  • Geofencing and zone management for robot navigation boundaries
  • Route optimization and path planning visualization
  • Alert system for maintenance needs and operational anomalies
  • Historical movement data analysis and heatmap generation
  • Multi-robot coordination and task assignment interface
  • Performance analytics dashboard with KPI tracking

Deliverables

  • Production-ready fleet management web application
  • Real-time robot tracking system with Mapbox integration
  • Administrative dashboard for fleet operations
  • Mobile-responsive interface for field technicians
  • RESTful API for robot data ingestion
  • Alert and notification system
  • Historical data analytics and reporting tools
  • Documentation for system integration

Technology Stack

Vue 3PiniaMapbox GL JSTypeScriptViteTailwind CSSNode.jsWebSocketPostgreSQLRedisExpress.jsChart.js
AI Platform
Live8 months

AskRudy.ai

AI-Powered Document Intelligence Platform

An advanced RAG-based AI chatbot that revolutionizes document interaction through multilingual translation and intelligent conversation capabilities. Features cutting-edge OpenAI multimodal technology for screenshot analysis and real-time text translation.

Live Demo

Key Features

  • RAG (Retrieval-Augmented Generation) architecture for accurate responses
  • Multi-format document support (PDF, DOCX, TXT, images)
  • OpenAI GPT-4 Vision integration for screenshot analysis
  • Real-time multilingual translation (50+ languages)
  • Intelligent document chunking and vector embeddings
  • Conversational AI with context-aware responses
  • Document highlighting and annotation tools
  • Export capabilities for translations and summaries
  • Collaborative workspace for team document analysis

Deliverables

  • Production-ready AI chatbot platform
  • Document processing pipeline with OCR capabilities
  • Multi-language translation engine
  • User dashboard with document management
  • Subscription management with Stripe integration
  • API documentation and integration guides
  • Mobile-responsive Progressive Web App
  • Analytics dashboard for usage tracking

Technology Stack

Next.jsNextUIVercel AI SDKReact-PDFFirebaseLangChainOpenAI GPT-4PineconeStripeTesseract.jsPDF.jsZustand
Interested in working together? Let's create something amazing!
Contact

Let's Work Together

Ready to bring your ideas to life? I'm always excited to work on interesting projects and collaborate with amazing people. Let's create something extraordinary together.

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