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Diego Blaer

Senior Full Stack Engineer

I build production software across the whole stack: interfaces, APIs, event pipelines and LLM features. I have also led the teams that ship it.

10+ years · Lead roles at Fetcher, OnPoint and Surefire Local

Currently at Zenda · Senior Full Stack EngineerArgentina · Remote

One feature, every layer

How a single feature travels through the system at Zenda, from the table a user scrolls to the model that scores it. Same engineer at every stop.

  1. Interface

    Virtualized tables, a layout engine and real-time collaboration that stay responsive under large event datasets.

    React · TypeScript · Yjs

  2. Gateway

    One graph over many domain services, designed so the frontend asks for exactly what it renders.

    GraphQL Federation

  3. Services

    Domain microservices in TypeScript and Python, behind Cognito auth and packaged in Docker.

    NestJS · FastAPI · AWS Cognito

  4. Queues

    Background jobs and smart-signal pipelines that aggregate data off the request path.

    BullMQ · Celery · Redis

  5. Data

    Transactional data in Postgres, analytical event data in ClickHouse, files in S3.

    PostgreSQL · ClickHouse · S3

  6. AI

    An LLM-powered assessment flow with production tracing and evaluation.

    LangChain · LangGraph · Langfuse

Toolkit

Frontend

  • React
  • Next.js
  • React Native
  • TypeScript
  • Tailwind CSS
  • React Query
  • Storybook

Backend

  • Node.js
  • NestJS
  • Python · FastAPI
  • GraphQL Federation
  • REST
  • PostgreSQL
  • MySQL
  • Redis

Event-driven

  • Kafka
  • RabbitMQ
  • BullMQ
  • Celery

AI

  • LangChain
  • LangGraph
  • Langfuse

Cloud & DevOps

  • AWS Cognito
  • AWS S3
  • Docker
  • GitHub Actions
  • OpenTelemetry

Testing

  • Jest
  • Vitest
  • Playwright
  • React Testing Library

Experience

Eight roles since 2012, from fintech and payments to AI recruiting.

  1. Oct 2025 – now

    • Deliver end-to-end features across a React/TypeScript frontend and a NestJS/FastAPI microservices backend using GraphQL Federation, PostgreSQL, Redis, BullMQ/Celery, AWS Cognito/S3 and Docker.
    • Lead the technical design of cross-cutting features spanning the frontend, the GraphQL gateway and domain services, balancing velocity with long-term maintainability.
    • Build and evolve Python services (FastAPI, SQLAlchemy/SQLModel) for data aggregation and smart-signal pipelines on PostgreSQL and ClickHouse.
    • Architected high-performance frontend workflows (virtualized tables, layout engine, real-time collaboration with Yjs) that stay responsive under large event datasets.
    • Built an AI-powered assessment feature with LangChain/LangGraph and Langfuse for production observability.
    • Raised release quality with Vitest, Jest and Playwright coverage.

    Stack

    React, TypeScript, NestJS, FastAPI, GraphQL Federation, PostgreSQL, ClickHouse, Redis, BullMQ, Celery, AWS, Docker, Yjs, LangGraph, Langfuse, Playwright

About

Senior Full Stack Engineer with 10+ years of experience building secure, production-grade web and mobile applications with React, Next.js, TypeScript, Node.js/NestJS and PostgreSQL. Experienced with microservices, event-driven systems and LLM-powered features.

Industries
Fintech and payments, social media, AI recruiting, business process software
Education
Bachelor's degree in Computer Engineering, National Technological University (UTN), 2012–2020
Location
Argentina, working remote
Leadership
Lead roles at Fetcher, OnPoint and Surefire Local; mentoring, architecture, accessibility

Let’s talk

Hiring for a senior full stack or frontend lead role? Tell me about the team and the problem.