Freelance Data & Software Engineer

Daniel
Vazquez
Lang

Helping businesses turn data into actionable insights with modern software solutions.

Get in touch Selected work
Portrait of Daniel Vazquez Lang

7+ Years · Data + Software

What I do

Services

  1. Data Engineering

    Reliable pipelines, warehouses and transformations that make data trustworthy and query-ready.

  2. Software Engineering

    Production-grade APIs, tools and internal apps built to scale with your business.

  3. AI Engineering

    LLM-agnostic AI products — custom frontends, API integrations, MCP servers, plugins and chatbots. Like Mucki, built to work with any model.

  4. Consulting

    Architecture reviews, roadmaps and hands-on guidance to level up your data platform.

Selected work

04 Projects

    • Mithril relationship graph linking entities to locations
    • Mithril map view with clustered assets
    • Mithril entity detail and connection timeline

    Mithril

    1 / 3

    • OSINT
    • Geospatial

    Mithril

    An open-source intelligence platform built on a relationship graph anchored in real-world location — linking people, assets and events across land, sea, air and orbit.

    • Mucki mascot
    • Mucki map analysis of a location
    • Mucki ALKIS cadastral parcel data view
    • Mucki points-of-interest analysis
    • Mucki sociodemographic breakdown for a district

    Mucki

    1 / 5

    • AI
    • Real Estate

    Mucki

    The first AI analysis assistant for real estate. Ask questions about locations, buildings and markets — Mucki analyses real data and delivers explainable answers in seconds.

    • EnerScan extracting fields from a German energy certificate
    • EnerScan structured export of extracted certificate data

    EnerScan

    1 / 2

    • AI
    • Document AI

    EnerScan

    Drop in German energy certificates (Energieausweise) and get every relevant field extracted into structured Excel or CSV in seconds — powered by Claude Vision.

    • Diagram of an ETL pipeline moving scattered sources into a warehouse

    Data Pipelines

    • Data Engineering

    Data Pipelines & Scrapers

    Custom scrapers, ETL pipelines and data platforms that turn messy, scattered sources into clean, query-ready datasets.

Experience

  1. Data & Software Engineer

    Current

    Freelance

    Relationship-intelligence web apps and AI agents: graph systems that map how companies and people connect, plus LLM/MCP tooling (LangChain, RAG, Model Context Protocol) that automates research, enrichment and outreach.

  2. Data Engineer

    PREA (Data Science-Driven Real Estate Platform)

    Fully automated ETL/ELT pipelines (Python, BigQuery, PostGIS, Airflow, dbt) and event-driven GCP architecture — modeling millions of records, including ALKIS cadastral data across German federal states.

  3. Full-Stack Developer

    El Pato Medien GmbH

    Backend and frontend for custom WordPress plugins (including a visual web-scraping plugin), with database design, server administration and deployment.

  4. Working Student, Backend Development

    i-ways sales GmbH

    Early backend development experience.

Tech stack

Tools of the trade

Python SQL dbt Snowflake Airflow PostgreSQL GIS AWS BigQuery Docker

Let’s work together

Have data worth
acting on?

Tell me about your project. I usually reply within a day.

Get in touch