Robbie Marcelo

About

14 years
of tech.

Tokyo-based Senior Engineering Manager. Originally from Manila, Philippines. Nine years writing code, five years leading engineering teams, and recently — a builder again.

I'm a senior engineering manager, former site reliability engineer, former agency founder, and currently — an engineering leader who picked up the keyboard again.

The best engineering teams don't need a manager to move. They need one who builds the conditions for movement — then trusts the system.

I've managed engineers across six countries. The most durable thing I've learned: psychological safety travels faster than any process ever will.

Senior Engineering Manager — Rakuten Payment Inc.

Managing 4 mobile engineering teams and 25 engineers on one of Japan's largest payment apps — 10M+ monthly active users and JPY 130 billion in monthly transactions. Recently shipped AI-powered code review that reduced defects by 35% and cut Lead Time for Changes by 20%.

Rebuilding — this blog

Re-engaging with hands-on coding after years in management. Learning agentic workflows, modern stacks, and what it feels like to ship things again. Writing about the journey in real time.

2012–2015
Fullstack Engineer — Proudcloud, Philippines

Ruby on Rails, greenfield startup work from pre-seed to seed

2015–2021
Lead Engineer → Lead SRE — Quipper, Philippines & Japan

Payment systems for 500K+ students, then microservices migration and $300K+ infra savings

2021–2022
Founder & CTO/CEO — AKARU LLC

Cross-border tech agency, 40 people, zero attrition, acquired Oct 2022

2021–2023
Engineering Manager — Manabie, Japan & Vietnam

Scaled from 80 → 150 engineers in 10 months across Japan and Southeast Asia

2023–now
Senior Engineering Manager — Rakuten Payment Inc., Japan

Mobile group — 4 teams, 25 engineers, 10M+ MAU payment app

What I love about engineering management mirrors what I loved about SRE: watching autonomous parts work together without a central coordinator. The craft is in building that — not in being the coordinator yourself.

I've run performance cycles, written career frameworks, led calibration across seven teams, and hired in Manila, Jakarta, Tokyo, and Hanoi. The metric I track closest isn't velocity or delivery rate. It's how many people grew into something bigger — and still reach out.

I put the keyboard down in earnest around 2021. Management consumed the calendar. PR reviews became process conversations. My production commit history went quiet.

Then the agentic era arrived, and the distance between what managers understand and what engineers are actually doing started to feel like a real liability. I picked it back up.

This site is the first thing I've built end-to-end in years — Astro, Tailwind, deployed on Cloudflare Pages. I'm writing about the experience as it happens in the Rebuild section of this blog.

RubyGolangTypeScriptPythonKubernetesAWSGCP

Also Kotlin, Swift, Shell, and whatever the problem calls for. AWS Solutions Architect — Associate (2018).

I split my time between managing large teams and re-learning what it feels like to be a beginner. Between leading engineers and figuring out what changed while I was in meetings.

This is what 14 years of software looks like when you refuse to fully leave the keyboard — even when the calendar suggested otherwise.