Building with AI daily · skills, scripts, comparisons

For engineering leaders
crossing into AI.

A peer one step ahead — 23 years building teams, now shipping with AI every day. Claude Code and Codex as the vehicles.

Skills, scripts, honest tool comparisons. Free, public, and posted as they earn their place.

23 Years in Tech
$130M Exit (PIA)
3 C-Level Roles
Dui Toledo, engineering leader and advisor

What I Ship

Skills, scripts, and honest comparisons from daily practice with Claude Code and Codex. Free, public, and grouped by the theme they earned their way into.

01

Orchestration

sprint (per-task teams), review-loop, subagents + worktrees.

02

Observability

cc_cost.py — weekly rate-limit math for Claude Code.

03

Skills as a system

The pattern behind cc_cost, pulse, xs, dj, li, sprint.

04

Tool comparisons

Opus vs Codex on real migrations, harness benchmarks.

// artifacts earn entries · themes grow as work accumulates

Where I Stand on AI

"The future has never been as unevenly distributed as it is today."

I spend my evenings and weekends building with AI — shipping real projects with Claude Code, comparing models on production tasks, running parallel agents in the cloud. Not reading about it. Doing it.

That hands-on work shapes how I think about the transition engineering organizations are going through. Many leaders know AI matters but aren't sure where to start or what to trust.

I bridge that gap — 23 years of building teams and shipping products, combined with daily experience using AI as a real tool, not a talking point.

Agentic AI Is Here

I run autonomous agents on real migration tasks and compare the output. The delegation model is changing faster than most orgs realize.

Hand-Coding Is Dead

AI writes most of the code now. The hard part is figuring out how to build production software in this new world — and that's where the real work is.

The Gap Compounds

The tools change every week. Reading about AI isn't enough — you need to carve out real time to practice, or the distance grows fast.

Leadership Must Adapt

AI-augmented teams work differently. The playbook for managing them is being written by the people actually doing it.

Where I've Built

From IC to CTO to COO. Each role taught me something different about building teams, systems, and companies.

PayNearMe VP Engineering
2022 — Present

Led Platform and Cloud Engineering. Modernized infrastructure, improved security and compliance. Built the incident management process from scratch. Now leading a cross-functional Quality and Reliability effort across Engineering, Product, and Operations.

Infrastructure Modernization Incident Management Cross-Functional Quality
NoRedInk VP Eng → COO → CTO
2015 — 2022

Started as a software engineer, grew to VP Engineering overseeing 35+ engineers. Expanded to COO running Operations, Finance, and People Ops. Then CTO leading a 45-person engineering department and 8-person People Ops team.

CTO to COO Nearshoring Functional Programming Org Scaling
Private Internet Access Engineer #1 → CTO
2012 — 2017

Joined as the first engineer. Built the technical foundation and grew into CTO. Scaled to acquisition with zero external funding.

$130M Exit Zero Funding Engineer #1 Full Stack Build
Earlier Roles IC → Lead
2003 — 2012

Started in a telecom R&D lab, moved through health insurance tech, then joined a UK startup remotely—first exposure to high-caliber distributed teams.

Remote Pioneer Self-Taught Brazil → Global

How I Think

Frameworks I've developed through practice. Not theory—systems I actually use daily.

📊

Systems Lag Teams

Your system is a lagging indicator of your team. Today's codebase reflects your team from years ago. To improve systems, invest in people, processes, and tools first—results follow with inevitable delay.

"Your system is a lagging indicator of your team. Today's system reflects your team from years ago."
🔧

3 Modes of Work

Stabilizers, improvers, and foundations. Every engineering decision falls into one of three modes. Knowing which mode you're in—and which you should be in—is half the job of leading a team.

"There's limited overlap between the work to build quick bridges to different destinations and the work to build a really big and strong bridge."
🎯

Your Circus, Your Monkeys

Align decision authority with accountability. Don't consensus your way to a Frankenstein solution. The goal of decisions is accuracy, not agreement.

"Your goal with decisions is not to make people happy. Your goal is to make good decisions."

Fast vs. Rushing

Speed comes from years of building competence, not from pushing harder right now. If you're slow, the question isn't "how do I rush?" but "what competence am I missing?"

"While rushing is about what you're doing now, being fast is about what you've done over the past several years."
👥

Leader, Manager, Expert

Three distinct roles in a startup—strategy, team building, and execution. Each demands different evaluation criteria. The job changes dramatically at every stage of scale.

Knowing which objectives lead to the best outcome and can be executed by the current staff is the hardest problem in leadership.

High-Standards Satisficer

Build an excellent pipeline, set a competence-driven bar, then commit to the first option that clears it. Combines the rigor of a maximizer with the decisiveness of a satisficer.

"It's much better to find a top-percentile choice in a great pool than the best option from mediocre alternatives."

What I'm Building

Current experiments, learning, and projects. Updated as I ship.

2026-04 [writing] The AI Engineering Leader's Map — free map for eng leaders past the Claude Code intro, chapter by chapter
2026-02 [ai] Rebuilt personal websites end-to-end with Claude Code on mobile
2026-02 [ai] Opus 4.6 vs Codex 5.3 — comparing AI models on real migration tasks
2026-01 [building] Pilecat — AI-native task consolidation from Slack/email, learning AI by building
2026-01 [ai] Parallel agents running workloads in the cloud

What I'm Reading

Books shaping how I think right now.

Vibe Coding

Vibe Coding

Gene Kim, Steve Yegge

Handpicked Tweets

What People Say

From First Round's Fast Track mentorship program.

Dui has had a profound impact on my life. The opportunity to connect with him has far exceeded any expectation I may have had. He's walked the path to technical leadership—depth of experience in how to advise and think through navigating my journey from IC to engineering management. He helped me find clarity on what I actually wanted, then set milestones to achieve it.

Andreas Dias · Engineering Manager · Mentee

Dui is a paragon of knowledge and wisdom with an incredibly diverse range of expertise. His holistic approach to mentorship, encompassing professional understanding and personal well-being, has been a game changer for me. In essence, Dui is more than a mentor; he's a catalyst for transformation.

Francisco Gonçalves · Senior Developer · Mentee

Get in Touch

Let's talk

Whether you're navigating an AI transition, scaling your engineering org, or figuring out your next move as a technical leader—I'm happy to chat.