# Daniel Saiz's Personal Website URL: https://dsaiztc.com Author: Daniel Saiz Description: Personal website featuring blog posts about software engineering, projects, and professional information. ## Site Structure ### Main Pages - [Home](/) - Personal website home page featuring latest content and introduction - [About](/about/) - Professional background, skills, and contact information - [Blog](/blog/) - Collection of articles about software engineering and technology - [Projects](/projects/) - Showcase of software development projects ### Blog Posts - [Introducing croni: cron-like scheduling for macOS](/blog/posts/introducing-croni.html) - Published: 2026-07-08 - Tags: CLI, Go, macOS, launchd, cron, Scheduling, Claude Code - Description: I built croni, a friendly CLI that wraps macOS launchd behind a cron-like interface — schedule recurring commands, especially claude -p prompts, without ever touching plist XML or launchctl. - [dev wkt: Git Worktrees for Parallel Development](/blog/posts/dev-worktrees.html) - Published: 2026-03-03 - Tags: CLI, Go, Developer Tools, Git Worktrees, Claude Code - Description: I've added opinionated support for git worktrees to dev via the dev wkt sub-command — create, navigate, and clean up worktrees for parallel development. - [dev: Two Weeks of Rapid Evolution](/blog/posts/dev-evolution.html) - Published: 2026-02-27 - Tags: CLI, Go, Developer Tools, Unix Philosophy, Claude Code - Description: How dev evolved through four major releases in two weeks, adding project scaffolding, tree views, plugins, and composable path lookup. - [Introducing dev: a CLI for navigating your projects](/blog/posts/introducing-dev.html) - Published: 2026-02-18 - Tags: CLI, Go, Developer Tools, Claude Code - Description: How I built dev, a small CLI tool that enforces an opinionated directory structure for all your repos and lets you fuzzy-navigate between them. - [Running Apache Kafka in KRaft mode](/blog/posts/running-apache-kafka-in-kraft-mode.html) - Published: 2026-02-18 - Tags: Apache Kafka, KRaft, Distributed Systems - Description: What I wish I had known when migrating Kafka clusters from ZooKeeper to KRaft mode. An introductory overview of KRaft architecture and what actually changes. - [Make time for what matters](/blog/posts/make-time-for-what-matters.html) - Published: 2025-03-27 - Tags: Time Management, Productivity, Web App - Description: How I discovered time blocking during my college days and created a minimalistic web app to help make time for what's important. - [Navigating OpenAI's JSON-Structured Outputs: Limitations and Solutions](/blog/posts/navigating-openai-json-structured-outputs.html) - Published: 2025-02-28 - Tags: OpenAI API, JSON Schema, Pydantic - Description: A practical guide to working with OpenAI's JSON-structured outputs, including common limitations and solutions based on real-world experience. - [Website Revamp and AI Development Experience](/blog/posts/website-revamp-and-ai-development.html) - Published: 2025-02-23 - Tags: website development, AI development, personal growth - Description: Reflecting on my website revamp journey and experience with AI-assisted development using Cursor IDE. - [Building an AI-Powered Personal Finance App](/blog/posts/building-ai-powered-personal-finance-app.html) - Published: 2025-02-23 - Tags: AI/ML, Personal Finance, Double-Entry Accounting - Description: Development of a personal finance app combining double-entry accounting with AI-powered expense classification. ### Projects - [croni](/croni/) - Date: 2026-06-17 - Tags: CLI, Go, macOS, Agent-ready, Developer Tools, Open Source - Description: A friendly CLI for scheduling recurring commands on macOS. Wraps launchd behind a cron-like interface — schedule cron, interval (--every), or one-shot (--at) jobs that survive reboots without touching plist XML or launchctl. Especially handy for scheduling claude -p prompts. Agent-ready by design: machine-readable JSON output (--json) on every command including errors, non-zero exit codes on failure, and never blocks on a prompt (non-TTY stdin fails fast instead of hanging). - [dev](/dev/) - Date: 2026-06-17 - Tags: CLI, Go, Developer Tools, Open Source - Description: A CLI tool that reduces cognitive load when navigating between development projects. Enforces an opinionated directory structure and provides fast fuzzy navigation. Supports git worktrees via dev wt (formerly dev wkt) for parallel development, plus agent-friendly flags (--json, --no-input, --no-color) for scripting and AI agents. - [ByWeeks](https://byweeks.com) - Date: 2025-03-27 - Tags: Web App, Time Management, Productivity, PWA - Description: A minimalistic time blocking web app that helps you make time for what's important. - [UC3M Alumni Database Analysis](/AlumniUC3M/) - Date: 2016-05-15 - Tags: Python, BeautifulSoup, Data Analysis - Description: Using BeautifulSoup to scrape Alumni data and analyze graduation timelines at Universidad Carlos III de Madrid. - [OpenStreetMap Data Wrangling](/OSMDataWrangling/) - Date: 2016-04-20 - Tags: Python, MongoDB, Data Analysis - Description: Data munging techniques to clean OpenStreetMap data, converting from XML to JSON format and importing into MongoDB. - [NYC Subway Dataset Analysis](/NYCSubwayAnalysis/) - Date: 2016-03-10 - Tags: Python, pandas, Data Visualization - Description: Statistical analysis to determine if weather affects NYC subway ridership. - [Biker Assistant](/PFC.pdf) - Date: 2015-09-01 - Tags: Android, Java, Neural Networks - Description: Android application for Bultaco Motors providing telemetry display, navigation, and intelligent range estimation. - [Secret Santa App](/secretsanta/) - Date: 2015-12-15 - Tags: Android, Java - Description: Android app for organizing Secret Santa events with automatic email notifications. - [MLP Java](https://github.com/dsaiztc/MultilayerPerceptron) - Date: 2015-11-01 - Tags: Java, Machine Learning, Open Source - Description: Java implementation of an Artificial Neural Network using EJML library. ## Professional Experience - Senior Software Engineer, Data Streaming Infrastructure at Shopify (2021-2024) - Engineering Manager & Technical Lead, Data Platform at Spotahome (2017-2021) - Software Engineer, Full Stack & Data Platform Analytics at CST International (2015-2017) ## Core Skills - Python - Java - Distributed Systems - Cloud Infrastructure - System Design - Data Engineering - Machine Learning - AI Engineering ## Content Guidelines - All dates use ISO format (YYYY-MM-DD) - Blog posts are ordered by date (newest first) - Projects are ordered by date (newest first) - External links open in new tabs - Content uses semantic HTML structure - Responsive design with mobile-first approach ## Contact Information - [GitHub](https://github.com/dsaiztc) - [LinkedIn](https://linkedin.com/in/dsaiztc) - [Twitter/X](https://x.com/dsaiztc)