Engineering Blog

Articles, architectural insights, and tutorials on Kotlin, Jetpack Compose, Flutter, Laravel, Nuxt, and modern engineering practices.

Jimmy Leonardo - Building the Camera App I Wanted to Use
3 min read

Building the Camera App I Wanted to Use

As a photographer, I kept wishing my phone camera felt more like film. So I built Rolla: EXIF photo frames, film simulation filters, Polaroid mode, and a light meter, all in one camera app.

photographyengineeringmobile development
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Jimmy Leonardo - The Bug That Wasn't Ours Pinned
3 min read

The Bug That Wasn't Ours

A Xendit SDK integration kept failing, card payments and transactions with nothing in our logs to explain why. It took a full day of debugging alongside Xendit's engineers to trace it to a conflict with Microsoft Clarity.

paymentengineeringdebuggingmobile developmentbugs
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Jimmy Leonardo - From One Integration Task to Speaking Every Team's Language
4 min read

From One Integration Task to Speaking Every Team's Language

I didn't plan to become the person who understands attribution, analytics, and marketing tooling better than most engineers do. It started with a small assignment at Cashbac: connect Mixpanel and AppsFlyer. I ended up learning six different platforms across two companies, and along the way, learning how to work with digital marketing, frontend, product, and analytics teams well enough that they trust me with their data.

engineeringmobile developmentanalyticsattributionmobile marketing
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Jimmy Leonardo - Why Buy a Beacon When Your Phone Already Is One
2 min read

Why Buy a Beacon When Your Phone Already Is One

Every merchant needed two imported BLE beacons for payment and visit tracking. I turned Android phones into beacon transmitters instead, no extra hardware required.

engineeringmobile developmentfintech
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Jimmy Leonardo - The Interview I Still Think About
3 min read

The Interview I Still Think About

In a job interview, I was asked if I could migrate a legacy Android app from Eclipse to Android Studio. I said yes. Three days into the job, I had to prove it, on UANGKU, a mobile e-wallet later acquired by Traveloka.

engineeringmobile development
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Jimmy Leonardo - The App I Built During a Flood That Got Me Hired Pinned
3 min read

The App I Built During a Flood That Got Me Hired

In February 2014, Jakarta flooded and I had nothing to do. I built an unofficial Android app for MyBOLT! 4G subscribers to check their data quota. A month later, it got me hired to build the official app.

personalengineeringmobile development
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