NC
Available for work · Mexico City, Mexico · UTC−6

I build

Lead Backend Engineer with 4+ years building production systems at scale. I design distributed backends and own features end to end — from gRPC microservices and the API gateway down to the Kubernetes and CI/CD that run them. I care most about correctness under failure: idempotency, compensation, and resilient integrations — and I build a lot on the side to keep learning across the stack.

See projectsGet in touch
engineer.ts
1const engineer = {
2  role: "Lead Backend Engineer",
3  based: "Mexico City",
4  focus: ["distributed systems", "reliability"],
5  stack: ["TypeScript", "NestJS", "gRPC"],
6  ships: "systems that don't fall over",
7};
TypeScript
NestJS
Node.js
gRPC
GraphQL
PostgreSQL
Prisma
Redis
Kafka
Kubernetes
Docker
GCP
Terraform
Datadog
Python
FastAPI
Rust
React
Next.js
Vite
MongoDB
OpenAI
TypeScript
NestJS
Node.js
gRPC
GraphQL
PostgreSQL
Prisma
Redis
Kafka
Kubernetes
Docker
GCP
Terraform
Datadog
Python
FastAPI
Rust
React
Next.js
Vite
MongoDB
OpenAI
By the numbers · platform Nicolás is a primary contributor to
0+
Years shipping production
0K+
Users served in production
0K+
Transactions handled
~0
Microservices contributed
0+
Side projects built
0
Languages in rotation
STEP 02Experience

Owning systems end to end — from design to production.

From requirements and system design through implementation, testing, and production deployment.

Scroll into the past
Jul 2023 — PresentPresent
Zazpay
Zazpay
Lead Backend Engineer
Full-time · Mexico City (Hybrid)

Lead backend engineer on a consumer-lending fintech — personal loans, BNPL, and store credit — spanning ~20 microservices, the API gateway, web/mobile frontends, and shared infrastructure. I led a small backend team and owned features from requirements and system design through implementation, testing, and production deployment.

  • Designed and shipped fault-tolerant distributed systems — idempotency keys, request timeouts, circuit breakers with graceful fallback, and compensation — that stay correct under partial failure.
  • Owned the personal-loans domain end to end, plus refinance, loan consolidation, and BNPL confirmation flows, with full audit trails and regression E2E coverage.
  • Hardened the core-banking (Mambu) integration — cut redundant calls, improved hot-path latency, and closed out double-charge and cascading-failure risks across the gateway, banking service, and protobuf contracts.
  • Designed and ran GitOps delivery in production with ArgoCD on GKE — an app-of-apps topology with a single source-of-truth manifests repo, per-cluster Kustomize overlays, and self-heal/prune sync.
  • Led the CI/CD migration from GitLab CI to GitHub Actions with GKE / Cloud Run deploys across ~8 services, including Kaniko builds, Workload Identity Federation, and gRPC health probes.
  • Instrumented the platform with Datadog (APM, logs, traces, monitors), managed cloud infrastructure with Terraform, and built an internal engineering-metrics tool tracking DORA metrics with AI-generated release summaries.
TypeScriptNestJSgRPC / ProtobufPrismaPostgreSQLKafkaRedisGKE / KubernetesGCPMambuSTP / SPEI
May 2022 — Jul 2023
Presta Vale
Presta Vale
Software Engineer
Full-time · Culiacán (Hybrid)

Full-stack engineer in a small, agile team building financial-services products from the ground up across a varied stack.

  • Independently built a financial-services chatbot on Hasura, PostgreSQL, and GraphQL, improving customer experience and support efficiency.
  • Delivered end-to-end across React, React Native, Next.js, LoopBack, Express, MongoDB, and MySQL.
  • Took ownership of cloud infrastructure, system design, and pipeline architecture beyond day-to-day coding.
ReactReact NativeNext.jsLoopBackExpressHasuraGraphQLPostgreSQLTwilio
Jul 2022 — Dec 2022
Softtek · Constellation Brands
Softtek · Constellation Brands
EA Software Intern
Internship · Monterrey

Built integrations across enterprise applications to improve enterprise-architecture visibility.

  • Programmed integrations across multiple applications with Node, Atlassian Forge, and LeanIX.
  • Helped map and document the company's application landscape and technological dependencies.
Node.jsAtlassian ForgeLeanIXConfluence
Nov 2021 — May 2022
John Deere Shared Services
John Deere Shared Services
Software Intern
Internship · Monterrey

Applied Agile methodologies in enterprise-level software development.

  • Developed test cases for Combine system software and performed SIL (Software-in-the-Loop) testing.
  • Automated report generation with Python, improving reporting efficiency.
PythonAgileTestingGit
STEP 03Selected projects

Things I build to keep learning across the stack.

Self-directed work spanning AI/ML, fintech tooling, sports tech, market data, and systems.

AI / ML★ Featured

Sunflow Agent

Conversational-AI brain for support & collections

The AI agent behind a multi-channel customer-support and collections platform built around the BNPL product. A LangGraph state machine orchestrates embedding-based intent classification, RAG over a Qdrant vector store, and tool-calling flows that hit live service APIs.

  • LangGraph state machine routing intent → RAG retrieval → tool calls against live APIs
  • Pluggable LLM provider layer (self-hosted / Ollama with an OpenAI fallback)
  • Embedding-based intent classification with OpenAI text-embedding-3
PythonFastAPILangGraphQdrantOpenAIRAG
Fintech★ Featured

Pied

Multi-tenant operations CRM with AI insights

A multi-tenant operations-management platform. Async FastAPI backend over MongoDB in a Router → Service → DB architecture, with a React 19 + Vite frontend. OpenAI GPT-4o-mini powers task auto-classification, confidence-thresholded auto-assignment, and an admin insights dashboard.

  • JWT multi-tenancy scoped by tenant_id, refresh-token rotation, RBAC, audit middleware
  • AI task auto-classification + workload-based auto-assignment
  • Deployed on GCP Cloud Run + Firebase Hosting with GitHub Actions CI/CD
FastAPIMongoDBReact 19ViteOpenAICloud Run
AI / ML

AI Video Pipeline

End-to-end AI YouTube production engine

A 7-stage async orchestrator that turns a topic into a finished video. Pluggable multi-provider stack (LLMs, image gen, AI video, TTS, STT) swappable via one-line YAML, with Remotion + FFmpeg rendering and resumable per-task checkpoints.

  • Agentic workflow of specialized prompts: researcher → scriptwriter → reviewer → visual directors
  • Dual workflows: long-form documentaries and zero-LLM 9:16 social shorts
  • Auto-dubbing into 6+ languages with word-level subtitle timing (Whisper)
PythonRemotionFFmpegClaudeGPT-4oElevenLabs
Market Data

Mayweather

Real-time prediction-markets data platform

Ingests Kalshi and Polymarket order books in real time. Async REST bulk-loaders plus persistent WebSocket streams feed an upsert-based sync into PostgreSQL time-series storage.

  • RSA-PSS WebSocket auth (Kalshi) + upsert sync (ON CONFLICT DO UPDATE)
  • Orderbook & price-tick time series with a 15-minute catalog refresh
  • Deployed as a Linux systemd service via GitLab CI/CD with auto-restart
PythonFastAPISQLAlchemyPostgreSQLWebSockets
Sports Tech

PadelRank

Real-time padel ranking & matchmaking app

A React Native + Expo mobile app for points-based ranking, matchmaking, and tournaments — with real-time updates and end-to-end-encrypted messaging over an offline queue.

  • Dynamic points-based ranking, matchmaking, and event registration
  • End-to-end encrypted messaging (Signal Protocol) with an offline queue
  • Shipped to iOS / Android / web via EAS Build
React NativeExpoSocket.ioSignal ProtocolEAS
Systems

Rust Git TUI

Terminal Git client built in Rust

A terminal-based Git client written in Rust — a side project to go deeper on systems programming and ergonomic TUIs.

  • Async TUI built on ratatui + tokio
  • Direct libgit2 bindings via git2
Rustratatuitokiogit2clap
STEP 04Skills

A deep backend core, with reach across the stack.

●●●● expert · ●●●○ strong · ●●○○ working · ●○○○ familiar

Languages

  • TypeScript
  • JavaScript
  • Python
  • SQL
  • Rust
  • C / C++

Backend & APIs

  • NestJS
  • Node.js
  • gRPC / Protobuf
  • REST design
  • GraphQL
  • FastAPI

Data & Messaging

  • PostgreSQL
  • Prisma
  • Redis
  • Bull / BullMQ
  • Apache Kafka
  • MongoDB

Cloud & DevOps

  • Google Cloud (GCP)
  • Docker
  • GitHub Actions
  • Kubernetes (GKE)
  • ArgoCD / GitOps
  • Terraform

Architecture

  • Microservices
  • Distributed systems / Sagas
  • Idempotency & correctness
  • Resilience patterns
  • Event-driven architecture
  • Caching strategy

Observability & Testing

  • Datadog (APM)
  • OpenTelemetry
  • Jest
  • E2E harness design
  • Testcontainers
  • Sentry / PostHog
STEP 05About

A bit about me.

Nicolás Cárdenas Valdez
Nicolás Cárdenas Valdez
Lead Backend Engineer
Mexico City, Mexico

I'm Nicolás — a backend engineer drawn to problems where being correct when things fail is the whole point: distributed systems, idempotency, resilient integrations. I work mostly in TypeScript and NestJS on GCP and Kubernetes, with Python and Rust for fun. Outside the day job I ship a steady stream of side projects — AI agents, data platforms, mobile apps — to keep learning across the stack.

Languages
  • SpanishNative
  • EnglishC1 / Advanced
  • FrenchLimited working
Outside work
  • Crypto trading & market analysis
  • Building & upgrading PC hardware
  • Automating everything
  • Video games
Education
  • 2019 — 2023
    B.S. Software Engineering — Ingeniero en Tecnologías Computacionales
    Tecnológico de Monterrey
    Campus Monterrey · focus areas include Information Security
  • 2016 — 2019
    High School Diploma
    Tecnológico de Monterrey
Certifications
  • Software Systems DevelopmentTecnológico de Monterrey · 2023
  • Implementation of Computing InfrastructureTecnológico de Monterrey · 2023
  • Introduction to Terraform CloudA Cloud Guru · 2022
  • AWS Academy — Machine Learning FoundationsAmazon Web Services · 2022
  • AWS Academy — Cloud FoundationsAmazon Web Services · 2022
  • Certified EA PractitionerSAP LeanIX · 2022
  • Postman Student ExpertPostman · 2022
STEP 06 · Contact

Let's build something that stays correct under failure.

Open to hybrid and remote roles. The fastest way to reach me is email or LinkedIn.

Emailniccarval@hotmail.comLinkedInin/nicolas-cardenas-valdezGitHubgithub.com/NicolasCV