Senior Software Engineer

Hello I'mEduardo Espinosa

Building payment infrastructure and product experiences that scale

10+ years of experience across fintech, marketplaces, and mobile engineering. I specialize in React, React Native, TypeScript, and building systems that handle real money with confidence.

View Projects

Shipped with

Instawork • Cornershop by Uber • Stateoftheart AI • Paybook • Marciano Studio

About

10+ years turning complex systems into clean products

I'm a Senior Software Engineer based in Querétaro, Mexico, with over a decade of experience building production systems across fintech, marketplaces, and mobile platforms. My focus is the intersection of user experience and system reliability.

I've led teams through payment infrastructure redesigns, modernized mobile codebases, and delivered compliance-sensitive workflows that handle real money and worker trust. I care about building interfaces that feel clear and trustworthy, while understanding the backend workflows, APIs, and monitoring systems that make those experiences reliable.

10+Years of experience
6Companies shipped with
50+Production projects

Fintech & Payments

Deep expertise in payment systems, worker payouts, debit cards, and financial integrations with Stripe, VGS, and NetSuite.

Cross-Platform Mobile

React Native at scale — type-safe, performant mobile experiences alongside modern web applications.

Backend Systems

Django, Python, Celery, and async workflows. Building reliable, observable, and maintainable backend infrastructure.

AI-Assisted Development

Leveraging Claude Code, Cursor, and LLMs for codebase exploration, refactoring, testing, and debugging.

Career

Experience & Impact

Senior Software Engineer

Instawork

2021 – 2025 • Remote, USA

  • Led frontend and integration work for Instawork Card (secure debit-card workflows), contributing to double-digit worker retention improvement
  • Redesigned NetSuite financial synchronization from event-driven to scheduled batch processing, reducing sync failures by ~90%
  • Delivered W-2 Instapay workflows enabling real-time wage access for workers, contributing to double-digit business margin improvement
ReactReact NativeTypeScriptPythonDjangoCeleryStripeVGSNetSuiteDatadog

Senior Frontend Developer

Cornershop by Uber

2021 • Remote, Mexico

  • Worked on a SWAT engineering team focused on urgent features and high-impact production issues
  • Contributed across React and React Native codebases
  • Strengthened ability to debug production issues and work across different product domains
ReactReact NativeTypeScript

Frontend Tech Lead / Co-Founder

Stateoftheart AI

2020 – 2021 • Remote, USA

  • Served as Frontend Tech Lead and founding-team member for an AI research platform
  • Led frontend architecture using Vue and Nuxt.js with GraphQL integration
  • Designed interactive visualizations mapping relationships between AI research papers, authors, models, and datasets
VueNuxt.jsGraphQLD3.jsTypeScript

Senior Frontend Developer

Paybook

2019 – 2020 • Remote, USA

  • Built embeddable fintech widgets for bank-account and tax-account synchronization
  • Designed reusable and customizable UI architecture for external client integrations
  • Improved asynchronous financial synchronization flows with clearer states and stronger error handling
ReactTypeScriptGraphQLFintech APIs

Senior Frontend Developer

Marciano Studio

2014 – 2019 • Mexico

  • Led frontend development across e-commerce platforms, enterprise tools, and data products
  • Defined reusable UI patterns and frontend implementation standards
  • Collaborated with clients, designers, and backend engineers on production systems
ReactVueJavaScriptHTMLCSSResponsive Design

Frontend Developer

Corebook

2012 – 2014 • Mexico

  • Built production web interfaces and reusable components
  • Developed strong foundations in JavaScript, responsive design, and browser compatibility
JavaScriptjQueryHTMLCSS

Work

Featured Projects

A selection of significant work across fintech, mobile, and platform engineering

NetSuite Financial Sync Redesign

Instawork

infra

Financial synchronization was unreliable and difficult to debug with event-driven triggers and direct model signals.

Role: Full-stack architect and implementer

Reduced synchronization errors by approximately 90% through scheduled batch processing, improved observability, and added idempotency controls.

DjangoCeleryPythonService ArchitectureDatadog

Instawork Card

Instawork

fintech

Workers needed secure, transparent access to earned wages through a branded debit card with real-time transaction visibility.

Role: Frontend and integration lead

Launched a secure debit-card product with transparent fees and transaction visibility, contributing to double-digit worker retention improvement.

React NativeTypeScriptVGSStripeSecure Payment Handling

W-2 Instapay

Instawork

fintech

W-2 workers wanted immediate access to earned wages rather than waiting for payday, but needed proper eligibility checks, tax handling, and safeguards.

Role: Full-stack lead

Delivered instant payout workflows with proper eligibility logic and tax/fee handling, contributing to double-digit business margin improvement.

ReactReact NativeTypeScriptPythonDjango+2

Meals & Breaks Compliance

Instawork

fintech

State-specific labor laws required careful handling of meal and rest break rules with clear product copy and safe defaults.

Role: Frontend and product workflow design

Implemented state-specific compliance workflows with safer derived values, clear product copy, and guardrails to reduce legal risk.

ReactTypeScriptState Compliance LogicData Validation

React Native TypeScript Migration

Instawork

mobile

Mobile app had mixed TypeScript and Flow/JavaScript, making refactoring difficult and creating type safety gaps.

Role: Migration lead and implementer

Migrated all shared components to strict TypeScript, improving type safety, developer experience, and maintainability across mobile surfaces.

React NativeTypeScriptFlowMobile Infrastructure

Virtualized Filters & Large-Data UI

Instawork

mobile

Workers were filtering through thousands of shift options, causing UI performance degradation and poor user experience.

Role: Component architecture and performance

Built virtualized filter components supporting single/multi-select, search, and select-all patterns, improving performance and UX in data-heavy interfaces.

ReactTypeScriptVirtualizationReact-WindowStorybook

Payment Ledger Micro-Frontend Migration

Instawork

platform

Legacy payment views needed modernization without disrupting partner web experiences.

Role: Micro-frontend architecture and implementation

Successfully migrated payment ledger to micro-frontend architecture, improving maintainability and enabling independent deployment.

ReactModule FederationMicro-frontendsPayment APIs

Stateoftheart AI Research Platform

Stateoftheart AI

platform

AI research ecosystem was fragmented across papers, authors, models, and datasets with no clear relationship mapping.

Role: Frontend Tech Lead and co-founder

Built interactive visualizations mapping AI research evolution, launched MVP, scaled through acquisition by Instawork.

VueNuxt.jsGraphQLD3.jsNeo4j

Paybook Embedded Fintech Widgets

Paybook

fintech

Financial institutions needed flexible, customizable widgets for bank and tax account synchronization without building from scratch.

Role: Widget architecture and implementation

Built reusable widget architecture adopted across multiple client sites, improving sync flows and trust through clearer state handling.

ReactTypeScriptEmbeddable ComponentsFinancial APIs

SIMAR – Marine Monitoring Explorer

Marciano Studio

platform

CONABIO needed an interactive public tool to explore marine monitoring data across Mexico's coastal regions.

Role: Technical lead, developer, and client relationship manager

Delivered an interactive geospatial explorer enabling researchers and the public to visualize real-time marine monitoring data.

VueLeaflet

Michelin Internal E-Learning Platform

Marciano Studio

platform

Michelin needed a web-based internal training platform that tracked learner progress and complied with the SCORM standard.

Role: Technical lead and developer

Built a SCORM-compliant e-learning platform enabling Michelin to author, deliver, and track employee training across the organization.

VueSCORM

MyTicket – Events Ticketing System

MyTicket

marketplace

Event organizers and attendees needed a reliable platform to publish events, manage availability, and purchase tickets online.

Role: Technical lead and developer

Built a full-featured online ticketing system supporting event management and real-time ticket sales.

Vue

Michelin Interactive Marketing Games

Marciano Studio

platform

Michelin and its sub-brands needed engaging web experiences to support marketing campaigns and increase audience interaction.

Role: Technical lead and developer

Delivered multiple interactive web games and experiences for Michelin marketing campaigns, driving audience engagement across brands.

VueAngular

Bticino Store CMS

Marciano Studio

platform

Bticino store needed a dynamic way to configure and manage product pages without requiring backend development or code changes.

Role: Frontend architect

Built a no-code CMS system with reusable React components enabling store managers to dynamically configure product pages and content layouts.

React

Expertise

Skills & Technologies

Languages

TypeScriptJavaScriptPythonSQL

Frontend & Mobile

ReactReact NativeNext.jsVueNuxt.jsTailwind CSSGSAPD3.jsComponent ArchitectureDesign SystemsStorybookResponsive UIPerformance Optimization

Backend & APIs

DjangoDjango REST FrameworkNode.jsGraphQLREST APIsService ArchitectureAPI IntegrationAdmin Tooling

Data & Async Systems

CeleryRabbitMQBatch ProcessingBackground JobsMySQLMongoDBNeo4jIdempotency PatternsFeature Flags

Payments & Fintech

StripeVGSHyperwalletNetSuite IntegrationWorker PayoutsDebit Card WorkflowsInvoicing & ReconciliationFinancial CompliancePayment Applications

Cloud, Testing & Observability

AWSDockerGitHub ActionsJestPytestDatadogStructured LoggingMetrics & MonitoringProduction DebuggingClaude CodeCursor IDE

Let's build something together

Open to senior roles, technical leadership, consulting, and interesting problems. Always up for a conversation.

Email

edan.espinosa@gmail.com

GitHub

github.com/tecnoloco

LinkedIn

linkedin.com/in/eduardo-eg/

Based in Querétaro, Mexico • Available remotely