# Nicolás Cárdenas Valdez

> Lead Backend Engineer building reliable distributed systems. 5+ years shipping production backends — gRPC microservices, API gateways, and the Kubernetes/CI-CD that runs them — with a focus on correctness under failure (idempotency, compensation, resilient integrations). Mostly TypeScript/NestJS on GCP and Kubernetes; Python and Rust on the side.

- Location: Mexico City, Mexico (he/him) · open to hybrid/remote
- Site: https://nicolascardenas.dev
- Email: niccarval@hotmail.com
- LinkedIn: https://www.linkedin.com/in/nicolas-cardenas-valdez-602322220
- GitHub: https://github.com/NicolasCV
- Structured profile (JSON Resume): https://nicolascardenas.dev/profile.json

## Experience

- **Lead Backend Engineer — Zazpay** (Jul 2023 – present, Mexico City). Lead backend on a consumer-lending fintech platform (~20 microservices, API gateway, web/mobile, shared infra). Led a small backend team; owned features from requirements and system design through implementation, testing, and production deployment. **Owned personal loans end to end — the company's highest-revenue product** — and **owned the BNPL product end to end**. **Owned Sunflow**, the multi-channel messaging product driving collections (cobranza) over WhatsApp/SMS/email/voice. **Led the AI-model integration with the data team** (embedding- and LLM-powered features). Built fault-tolerant money movement (idempotency, timeouts, circuit breakers, compensation) and hardened the Mambu core-banking integration; designed GitOps delivery with ArgoCD on GKE; led the GitLab CI → GitHub Actions migration; instrumented the platform with Datadog + Terraform.
- **Software Engineer / DevOps — Nolu.AI** (2025 – present, remote, contract). Designed, developed, and deployed end-to-end products with AI integrations for client companies. For **Happymile** (cross-border US/MX trucking & logistics), replaced slow manual Excel reconciliation with a Python/FastAPI engine (pandas, MongoDB) that auto-classifies freight routes and computes extra-kilometer and toll costs, behind a React/TypeScript operator app on Cloud Run + Firebase — then extended it into a multi-region Transportation Management System (FastAPI + DynamoDB, React) on AWS ECS Fargate + Amplify with Terraform IaC and GitHub Actions CI/CD. Also delivered the **Pied** operations CRM. Owned architecture, deployment, and CI/CD throughout.
- **Software Engineer — Presta Vale** (May 2022 – Jul 2023, Culiacán). Full-stack engineer building financial-services products. Built the authentication gateway, refactored legacy code behind new and more secure adapters, and built a Hasura/GraphQL chatbot — across React, React Native, Next.js, LoopBack, and Express.
- **EA Software Intern — Softtek / Constellation Brands** (Jul 2022 – Dec 2022, Monterrey). Enterprise-architecture integrations with Node, Atlassian Forge, and LeanIX.
- **Software Intern — John Deere Shared Services** (Jun 2021 – May 2022, Monterrey). SIL testing and Python report automation under Agile.

## Selected projects

- **Sunflow Agent** (Python, FastAPI, LangGraph, Qdrant, OpenAI): conversational-AI agent for support & collections — a LangGraph state machine over embedding-based intent classification, RAG, and tool-calling, with a pluggable LLM provider layer.
- **Pied** (FastAPI, MongoDB, React 19, OpenAI): multi-tenant operations CRM with AI task auto-classification and an insights dashboard; JWT multi-tenancy, RBAC, audit logging.
- **AI Video Pipeline** (Python, Remotion, FFmpeg): 7-stage async orchestrator with a pluggable multi-provider stack (LLMs, image, video, TTS, STT).
- **Mayweather** (FastAPI, PostgreSQL, WebSockets): real-time prediction-markets ingestion of Kalshi/Polymarket order books with time-series storage.
- **PadelRank** (React Native, Expo, Socket.io): real-time ranking & matchmaking with end-to-end-encrypted messaging.
- **Happymile tooling** (Python, FastAPI, React, MongoDB, DynamoDB, GCP + AWS): logistics workflow automation — an Excel-replacement reconciliation/costing engine plus a multi-region Transportation Management System for a cross-border trucking company.
- **Rust Git TUI** (Rust, ratatui, tokio, git2): terminal Git client.

## Skills

- Languages: TypeScript, JavaScript, Python, SQL, Rust, C/C++
- Backend: NestJS, Node.js, gRPC/Protobuf, REST, GraphQL, FastAPI
- Data & messaging: PostgreSQL, Prisma, Redis, Bull/BullMQ, Apache Kafka, MongoDB
- Cloud & DevOps: GCP, Kubernetes (GKE), Docker, GitHub Actions, ArgoCD/GitOps, Terraform
- Architecture: microservices, distributed systems & sagas, idempotency, resilience patterns, event-driven architecture, caching
- Observability & testing: Datadog, OpenTelemetry, Jest, Testcontainers, E2E harness design

## Education

- B.S. Software Engineering (Ingeniero en Tecnologías Computacionales), Tecnológico de Monterrey, 2019–2023.

## Languages

- Spanish (native), English (C1), French (limited working).