Steven Mendez

Full Stack Engineer

Managua, Nicaragua (UTC−6)|stevenampaiz@gmail.com|linkedin.com/in/steven-mendez-dev|github.com/Steven-Mendez|stevenampaiz.com

Remote · Available for US time zones, flexible for EU

Professional Summary

I'm a full-stack engineer who builds and ships products end to end — and owns the outcome, not just the ticket. I move across the stack and pick the tool that fits the problem in front of me, whether that's a real-time backend, an AI-powered feature, or the interface people actually use. I like ambiguous problems and seeing them through from first idea to production.

Technical Skills

Languages: TypeScript / JavaScript, Python, C#, SQL

Frontend: React, Next.js, TypeScript, Tailwind CSS, HTML5/CSS3

Backend: FastAPI, Django, Flask, ASP.NET, REST APIs, Socket.IO, Pydantic, SQLAlchemy

AI & Data: LLM/RAG integration, LangChain/LangGraph, vector databases (pgvector, Qdrant), data pipelines, web scraping

Cloud & DevOps: AWS, Docker, CI/CD, Git

Databases: PostgreSQL, Microsoft SQL Server, Redis

Experience

Dupely

Dec 2025 - May 2026

Backend Engineer · Contract · via WERN

Remote

Built high-performance REST APIs in Python and FastAPI to serve real-time product data to the browser extension and mobile app.
Designed and maintained multi-vendor data pipelines ingesting product details, pricing history, and availability from major marketplaces (Amazon, Walmart, eBay) — indexing 5K–10K products during the beta phase — with caching and fallback handling to reduce reliance on third-party providers.
Delivered real-time backend events over Socket.IO and enrichment APIs (reviews, availability, similarity explanations) for a responsive client experience.
Worked within a ~10-engineer team, integrating third-party data providers (Bright Data, Oxylabs, Keepa, BlueCart) and managing persistence across PostgreSQL, Redis, and Qdrant on AWS.

Confidential E-Learning Platform

Dec 2024 - Nov 2025

Full Stack & AI Engineer · Contract · via WERN

Remote

Integrated AI into the platform: LLM/RAG retrieval over learning content with vector search (pgvector) and agent/tool orchestration (LangChain/LangGraph) to ground assistant responses.
Designed and shipped, end to end, a node-and-connector visual configuration tool (Next.js/React/TypeScript) that lets non-technical users configure conversational-agent behavior across scenarios.
Contributed full-stack to building the platform — Django/Python (FastAPI) services and React/Next.js/TypeScript interfaces.

WERN

Dec 2024 - Present

Freelance Software Engineer

Remote

Delivered contract software engineering for WERN's clients, owning the work from data and APIs through to the interfaces users see.
Engagements include Dupely (a real-time shopping assistant) and a confidential AI-powered e-learning platform — backend services, data pipelines, AI/LLM features, and web interfaces.

Universidad Nacional de Ingeniería (UNI)

Jan 2023 - Dec 2024

Systems Analyst · Full-time

Managua, Nicaragua · On-site

Maintained and modernized the university's mission-critical ASP.NET / SQL Server budget system, used by 400–700 staff across the institution with peaks of 100–200 concurrent users.
Optimized complex SQL Server queries over a decade of accumulated financial data — cutting a critical report from ~20 minutes to 15–30 seconds, and most heavy queries from ~5 minutes to under 10 seconds.
Proposed and prototyped a React.js front-end architecture to modernize the legacy UI, improving maintainability and user experience.
Mentored 5–10 interns, introducing modern development practices and clean-code standards to the team.

Selected Project

Personal Portfolio stevenampaiz.com

Next.js · React · TypeScript · GSAP · WebGL

Designed and built a liquid-glass personal site with WebGL/GSAP motion, full SEO and structured data, and CI-enforced accessibility & SEO budgets (Lighthouse CI gated at ≥95); optimized the hero image from 19 MB to 446 KB (~98% smaller).

Education

Universidad Nacional de Ingeniería

Mar 2019 - Dec 2023

B.S. in Computer Engineering

Managua, Nicaragua

Languages

Spanish — Native|English — Professional working proficiency (CEFR B2)

Professional Summary

Technical Skills

Languages: TypeScript / JavaScript, Python, C#, SQL

Frontend: React, Next.js, TypeScript, Tailwind CSS, HTML5/CSS3

Backend: FastAPI, Django, Flask, ASP.NET, REST APIs, Socket.IO, Pydantic, SQLAlchemy

AI & Data: LLM/RAG integration, LangChain/LangGraph, vector databases (pgvector, Qdrant), data pipelines, web scraping

Cloud & DevOps: AWS, Docker, CI/CD, Git

Databases: PostgreSQL, Microsoft SQL Server, Redis

Experience

Dupely

Dec 2025 - May 2026

Backend Engineer · Contract · via WERN

Remote

Built high-performance REST APIs in Python and FastAPI to serve real-time product data to the browser extension and mobile app.
Designed and maintained multi-vendor data pipelines ingesting product details, pricing history, and availability from major marketplaces (Amazon, Walmart, eBay) — indexing 5K–10K products during the beta phase — with caching and fallback handling to reduce reliance on third-party providers.
Delivered real-time backend events over Socket.IO and enrichment APIs (reviews, availability, similarity explanations) for a responsive client experience.
Worked within a ~10-engineer team, integrating third-party data providers (Bright Data, Oxylabs, Keepa, BlueCart) and managing persistence across PostgreSQL, Redis, and Qdrant on AWS.

Confidential E-Learning Platform

Dec 2024 - Nov 2025

Full Stack & AI Engineer · Contract · via WERN

Remote

Integrated AI into the platform: LLM/RAG retrieval over learning content with vector search (pgvector) and agent/tool orchestration (LangChain/LangGraph) to ground assistant responses.
Designed and shipped, end to end, a node-and-connector visual configuration tool (Next.js/React/TypeScript) that lets non-technical users configure conversational-agent behavior across scenarios.
Contributed full-stack to building the platform — Django/Python (FastAPI) services and React/Next.js/TypeScript interfaces.

WERN

Dec 2024 - Present

Freelance Software Engineer

Remote

Delivered contract software engineering for WERN's clients, owning the work from data and APIs through to the interfaces users see.
Engagements include Dupely (a real-time shopping assistant) and a confidential AI-powered e-learning platform — backend services, data pipelines, AI/LLM features, and web interfaces.

Universidad Nacional de Ingeniería (UNI)

Jan 2023 - Dec 2024

Systems Analyst · Full-time

Managua, Nicaragua · On-site

Maintained and modernized the university's mission-critical ASP.NET / SQL Server budget system, used by 400–700 staff across the institution with peaks of 100–200 concurrent users.
Optimized complex SQL Server queries over a decade of accumulated financial data — cutting a critical report from ~20 minutes to 15–30 seconds, and most heavy queries from ~5 minutes to under 10 seconds.
Proposed and prototyped a React.js front-end architecture to modernize the legacy UI, improving maintainability and user experience.
Mentored 5–10 interns, introducing modern development practices and clean-code standards to the team.

Selected Project

Personal Portfolio stevenampaiz.com

Next.js · React · TypeScript · GSAP · WebGL

Designed and built a liquid-glass personal site with WebGL/GSAP motion, full SEO and structured data, and CI-enforced accessibility & SEO budgets (Lighthouse CI gated at ≥95); optimized the hero image from 19 MB to 446 KB (~98% smaller).