Hector Rosado

Full-stack and AI engineer with 10+ years of experience in software engineering for web and mobile products, APIs, and production AI systems—including productivity, B2B SaaS,

and assistant-style experiences. Deep experience in LLM applications (RAG, prompts, evals,

guardrails, cost and latency) alongside modern full-stack delivery (React, Node.js, cloud).

Committed to secure design, efficient execution, and systems that stay reliable after launch.

Experience

Full-Stack & LLM Engineer — Copy.ai

May 2025 – Mar 2026

• Shipped React/Next.js UI and Node.js/TypeScript REST APIs with partner integrations for workflows, chat, and GTM (content, prospecting, leads, localization).
• Ran production maintenance with structured logging, metrics, tracing, and CI/CD rollouts, including monitoring, debugging, and hotfixes.
• Engineered agentic RAG with LangChain, LangGraph, Pinecone, and OpenAI (embeddings plus Chat Completions), using chunking, retrievers, tool routing, and caching for customer-grounded answers.
• Improved median RAG-path latency by ~30% in production telemetry versus the prior baseline, after retrieval and routing tuning.
• Owned prompt and safety work—LangSmith (tracing, eval runs), prompt versioning, offline checks, and guardrails—to keep copy on-brand and policy-safe across segments.
• Operated a multi-model LLM layer with the OpenAI SDK (streaming) in Node.js and Python services, applying routing, token budgets, batching, concurrency limits, and cost-aware fallbacks.

Full-Stack & AI Engineer — Akiflow

Jun 2023 – Apr 2025

• Developed TypeScript/React UI and Node.js services for calendar, tasks, and inbox, using TanStack Query and Redux for optimistic updates, cache refresh, and conflict handling.
• Built AI assistant experiences with the OpenAI SDK—streaming, structured outputs, tool calls for calendar slots and events, prompts, and token caps—cutting average tokens per successful assistant turn by ~25% after prompt and routing changes (production usage vs. prior baseline).
• Connected Google Calendar and Microsoft Graph–style calendars with OAuth 2.0 and REST (provider SDKs and HTTP clients), keeping events and tasks in two-way sync.
• Processed webhooks with signed payloads (HMAC) and ran queue-backed background jobs with retries and exponential backoff for incremental updates, with work structured so a repeat run would not corrupt or duplicate outcomes.
• Shipped partner-facing REST APIs from Node.js with JSON Schema and OpenAPI-style validation, rate limits, and stable error responses.

Full-Stack Developer — Flash Technologies

Apr 2021 – Jun 2023

• Worked as a full-stack developer across 10+ Flash ecosystem products, using TypeScript with React and Next.js on the web, React Native for Flash Mobile Wallet (flash-mobile-wallet), and DeFi projects such as dashboards, DEX, staking, and launchpads.
• Built the backend in Node.js and Express (TypeScript) with solid routing and validation, used PostgreSQL, MongoDB, and Redis together (relational + document + cache), and kept three client surfaces—Next.js, React web, and React Native—on the same REST APIs.
• Integrated Stripe into the Flash Transfer project (Payment Intents and Checkout, customers and payment methods, signed webhooks, retry-safe keys), with server-side checks so payment state stayed correct when Stripe or the app retried.
• Improved release quality with Jest and ESLint in CI, targeted static analysis, and third-party security reviews, working with product through staging, releases, and post-launch fixes.

Full-Stack Developer — ICICB Group

Jan 2019 – Mar 2021

• Delivered internal platform projects for product and operations: TypeScript/React SPAs for launch and roadmap tracking, partner admin tooling, and operational dashboards, with Redux, axios, JWT or session-based authentication, and RBAC across routes and UI.
• Implemented the Node.js and Express REST APIs behind those programs—structured routing, input validation, and consistent JSON error responses—for React web and mobile clients under shared API contracts.
• Supported the same platforms with a PostgreSQL, MongoDB, and Redis data tier (schema design, migrations, query tuning) and Node.js worker processes for webhook ingestion and asynchronous reconciliation, isolating long-running partner and settlement-style work from request paths.
• Ran a partner-integration initiative across 5+ critical external systems using outbound REST clients and inbound webhooks, with operational dashboards and alerting for failures, latency degradation, and queue depth.
• Containerized services with Docker, released them through CI/CD pipelines, and monitored API latency, error rates, and upstream dependency health with centralized logging, metrics, and environment-wide alerts.

Web & Mobile Developer — Beyond Finance

Jun 2016 – Dec 2018

• Delivered full-stack features for a consumer debt-resolution product (clear payoff paths, lower monthly payments, multi-year plans).
• Shipped Node.js (Express/Koa) REST APIs on AWS EC2 with CloudWatch for PM2/app and system logs.
• Configured AWS Budgets and CloudWatch alarms for spend, outages, and CPU spikes.
• Managed MongoDB collections and migration scripts for releases.
• Designed landing pages and client dashboards in React, integrating REST APIs and Redux for state.
• Consolidated legacy iOS/Android apps into a React Native app and published to the App Store and Google Play.
• Owned CI/CD, signing certs/keystores, native modules where needed, and dependency upgrades.

Education

B.S. in Computer Science from the Colegio Universitario de San Juan