iiinova — where your digital self keeps evolving

Piotrek Jeremicz @jeremicz.com · 30/09/2026

My first #Mac mini from 2009 is retiring too - well deserved. It sent almost 2 million notifications and synced dozens of terabytes of data. 🖥️ Carried it to school for presentations, and for the last 7 years it ran #ZarazJade. 🎒 Time to finally put it to rest. 🙏 #DevDiary

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Piotrek Jeremicz @jeremicz.com · 30/09/2026

I admit, a bit of sadness crept in. I wrote this backend back when we romantically cared about every single line of code. 💭 Built the whole thing in #Nova, over many months. 🛠️ But pragmatism wins. Backup done, database dumped. Shutting down #ZarazJade v3. 🔌 #DevDiary

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Piotrek Jeremicz @jeremicz.com · 30/09/2026

#Database archived, #backend ready to be cut off. Ran non-stop for 7 years. 📦 Most important for me: shutting down one version of #MySQL. Frees up RAM - and RAM is precious! 💾 From now on, the old #api just returns a message telling you to update. ⚠️ #DevDiary

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Piotrek Jeremicz @jeremicz.com · 30/09/2026

Today's the day - cutting off the old #ZarazJade backend. Migrated almost 1,800 accounts, 99% of users. 🚀 The rewrite was needed because the old service couldn't support multiple cities in the app. 🏙️ Not a blocker anymore, but I need to free up resources to build more. 🔧 #DevDiary

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Piotrek Jeremicz @jeremicz.com · 29/09/2026

So yes, I know CoreData too - but I also remember to add a pop-up at app launch that lets me painlessly migrate 99.9% of users to a new backend. 📲 #ProductEngineer #iOSDev #DevDiary

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Piotrek Jeremicz @jeremicz.com · 29/09/2026

Things are changing so fast right now that we don't even know what it'll look like once the dust settles. So I've decided to grow toward being a Product Engineer - still a developer, but also a product manager who cares not just about code quality, but about User Experience too. 🧭

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Piotrek Jeremicz @jeremicz.com · 29/09/2026

That's exactly why I'm choosing the wider waters - the more I understand of the whole process, the better I can actually use #AI, instead of just waiting on its answer. 🌊

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Piotrek Jeremicz @jeremicz.com · 29/09/2026

Developer growth has always been a core part of this industry, but how do you even plan your learning when so much knowledge now hides behind a simple prompt: "Hey agent, please make..."?

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Piotrek Jeremicz @jeremicz.com · 29/09/2026

A lot has changed since that advice I never took. I've come to realize I do want to be a specialist - just a different kind: not in one technology, but in the entire environment I work in. 🎯

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Piotrek Jeremicz @jeremicz.com · 29/09/2026

Following that logic - I've been a generalist for 15 years, building software across @Apple platforms. I can build a backend, handle analytics and tests. I keep getting more comfortable configuring entire environments and guarding against production issues. 🛠️

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Piotrek Jeremicz @jeremicz.com · 29/09/2026

▶️ Do I need to have my own product? Years ago, during a technical interview, I heard: "You need to specialize, ideally in #CoreData. It's the future, you'll always have a job." Looking back after all these years, I have to admit the universe's lottery played a pretty nasty trick here. 😅

A smartphone displays an update notification on a wooden table, surrounded by a laptop, potted plants, and colorful pens.

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Piotrek Jeremicz @jeremicz.com · 28/09/2026

Before setting a shutdown date for the legacy backend, I checked where my users actually were. 🔍 #ZarazJade was initially built for iOS 26, but it quickly turned out I had to go "a year lower" - which let me keep more users. 📱 #DevDiary

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Piotrek Jeremicz @jeremicz.com · 28/09/2026

The #ZarazJade migration itself went super fast - the lines crossed after a few days, but the tail dragged on for weeks. 📈 I sped things up with a pop-up about the update. Every app should be able to show a message from its backend! 💬 Now, I have even more than 💯 ! #DevDiary

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Piotrek Jeremicz @jeremicz.com · 28/09/2026

It's been over 60 days since the #ZarazJade 4.0 update. 🎉 Over several months I rewrote the entire backend, which forced a migration of existing users. A delicate process, so I wanted to handle it deliberately. 🧭 @claudeai prepared reports for me along the way. 📊 #DevDiary

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Piotrek Jeremicz @jeremicz.com · 25/09/2026

I am patient, I am waiting... I am waiting... 🧘‍♂️

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Piotrek Jeremicz @jeremicz.com · 24/09/2026

It was an amazing day 🌟. Now, it’s time to rest… 😌💤

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Piotrek Jeremicz @jeremicz.com · 22/09/2026

As fast as AI builds products, it creates technical debt even faster. Lots of .md files, half-finished code, and plenty of ghosts. 👻 Starting today: one module per release, cleaned up properly. 🧹 Small modules are the best win in the age of AI. ✨ #TechnicalDebt #DevDiary

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Piotrek Jeremicz @jeremicz.com · 17/09/2026

If you're even a little curious about compilers, LLVM, or just want to grow as a #Swift developer - apply next year. It's one of the best decisions I made this year. 🙌 #SwiftMentorshipProgram #Swift #DevDiary

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Piotrek Jeremicz @jeremicz.com · 17/09/2026

My slides and the code examples from the talk are up on GitHub if you want to dig into the details: 👇 github.com/piotrekjere...

github.com

GitHub - piotrekjeremicz/speaking

Contribute to piotrekjeremicz/speaking development by creating an account on GitHub.

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Piotrek Jeremicz @jeremicz.com · 17/09/2026

What a day! 🎉 Yesterday's Swift Mentorship '26 Demo Showcase - Part 1 was incredible. Getting to present what I built with my mentor Augusto over these 10 weeks, and seeing what the other mentees worked on, was honestly one of the highlights of this whole program. 🚀

A person with headphones and a microphone sits at a desk with multiple screens displaying code and slides, ready for a presentation.

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Piotrek Jeremicz @jeremicz.com · 16/09/2026

It's happening today! 🎉 Swift Mentorship '26 Demo Showcase - Part 1 starts in a couple hours (17:00 CEST). I'll be presenting what I built with my mentor these last 10 weeks. 🚀 Join us 👇 forums.swift.org/t/swift-men... #SwiftMentorshipProgram #Swift #DevDiary

Colorful abstract swirls with bold text announcing the Swift Mentorship '26 Demo Showcase on September 16 and 23.

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Piotrek Jeremicz @jeremicz.com · 15/09/2026

From my first bug-fix task to working on #LLVM itself and improving `dwim-print` - it's been the most intense learning sprint I've had in years. Tomorrow I finally get to show it off. 🧠

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Piotrek Jeremicz @jeremicz.com · 15/09/2026

This week is the real finale! 🎉 The #SwiftMentorshipProgram 2026 wraps up tomorrow with the Demo Showcase and I get to present what I've been building with my mentor Augusto these last 10 weeks. 🚀

Colorful, swirling lines on a gradient background feature the text "Swift Mentorship '26 Demo Showcase" with dates below.

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Piotrek Jeremicz @jeremicz.com · 14/09/2026

The #SwiftMentorshipProgram has come to the end... Now, I have to cook the short talk about it. Stay calm!

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Piotrek Jeremicz @jeremicz.com · 10/09/2026

I hate agentic coding! 😤 An idea popped into my head - two prompts, some low-hanging fruit, sit down and cash in. 💰 Problem: #appleOS27 is coming, new features to finish first. I promised myself I'd finish before starting. 🎯 Then there's #Shipaton too... Maybe I could... 🤔

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Piotrek Jeremicz @jeremicz.com · 09/09/2026

Every morning my daily report now includes a summary of #AppStore ratings and feedback. 📊 It's a small thing, but it means I never have to guess whether the changes are working - the numbers just tell me. 📈 Next up: making sure I actually act on what they say. 🔧

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Piotrek Jeremicz @jeremicz.com · 09/09/2026

I'm working on an improved Feedback feature in #ZarazJade - a direct line to users. 🗣️ Those two one-star reviews still cross my mind - could've caught them earlier if feedback was easier to give. 💬 Another feature needs time to mature, so there's room for this indulgence. 😉

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Piotrek Jeremicz @jeremicz.com · 09/09/2026

In the first few weeks after the update, #ZarazJade got two one-star reviews. ⭐ The #AppStore lets you reply to reviews, which gives you a direct line to the user. I fixed the bugs, got a thank-you in return. 🙏 So version 4.1 now has Feedback built right in - reachable from anywhere. 💬

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Piotrek Jeremicz @jeremicz.com · 07/09/2026

There's another side to this too. I have a job, I'm stable. But the dev market right now is uncertain - a lot has changed because of #AI. 🤖 I talk to a lot of people, and uncertainty comes up in conversation far more often than it used to. People don't deserve to live with that kind of feeling. 💭

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Piotrek Jeremicz @jeremicz.com · 07/09/2026

Just got this email. Honestly, it made me smile - I'd completely forgotten about this #recruitment process. Or maybe not forgotten exactly, I just knew it wasn't the right moment. 📧 Nice that someone remembered, even if it was a mass reply. Date's in the calendar - I'll try again next year. 📅

A rejection email outlines that other candidates were chosen, and mentions a limit on yearly applications for the same role.

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Piotrek Jeremicz @jeremicz.com · 07/09/2026

Another challenge in #ZarazJade was migrating from the old #database to the new one. At its peak, I had ~30k users, but many dropped off while the old version went unmaintained. 📉 Losing the most loyal ones stung the most, which is why I check the migration progress report every single day. 🔍

Data visualization showing user migration statistics for Zaraz Jade, highlighting activity windows, migration progress, and legacy version distribution.

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Piotrek Jeremicz @jeremicz.com · 07/09/2026

The hardest part was the vehicle position data. My server polls the provider every 10 seconds. All kinds of weird things happened - CRON wouldn't fire, data came back malformed, and sometimes it even managed to corrupt the database. 😬 Eventually I got the service to a reasonably stable state. ✅

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Piotrek Jeremicz @jeremicz.com · 07/09/2026

A month since #ZarazJade hit prod - it's been a tough road, and the last few days proved it can break anywhere. 😅 Public transport is incredibly tough because of the sheer volume and quality of the data - but I want to do this right. 🎯 I had to build in some safety nets. 🛡️

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Piotrek Jeremicz @jeremicz.com · 04/09/2026

Getting recognized in front of the whole audience is another thing entirely. 🏆 That wasn't even on my goals list! Feels like a good moment to look back at last year's goals. 📋

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Piotrek Jeremicz @jeremicz.com · 04/09/2026

It's almost been 3 months since #WWDC26! Time really does fly. 🕐 It was an incredibly special #AppleEvent for me. Getting picked in the lottery, winning #SwiftStudentChallenge, or getting your app featured - that's one thing. 🎟️

A modern, curved building surrounded by greenery and golden grass under a cloudy sky, suggesting a serene outdoor environment.

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Piotrek Jeremicz @jeremicz.com · 04/09/2026

#Claude is great for summarizing things. 🤖 #ZarazJade is migrating to a new backend - going really smoothly since I actually know what's happening now. 📊 The agent pulls in a dozen+ data sources daily and builds a report. Highly recommend! ✅

A detailed project status report outlines migration progress, subscription data, and backend sync issues for AboutToGo/Zaraz Jade.

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Piotrek Jeremicz @jeremicz.com · 03/09/2026

Some worry agents will take their jobs. I got something far more valuable instead: more time, at a much lower cost. ⏳ If you're in Warsaw, or want a great public transport app in your city, give it a try! 🚌 apps.apple.com/us/app/zara...

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Piotrek Jeremicz @jeremicz.com · 03/09/2026

None of this would be possible without #AI though. #LLM models genuinely gave me more time - doing faster, in the background, what I'd otherwise squeeze in between family, work, and sleep. 🤖

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Piotrek Jeremicz @jeremicz.com · 03/09/2026

After nearly four years away, the project is back - giving me great motivation to finally tackle all the ideas I've collected over the years. 💡

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Piotrek Jeremicz @jeremicz.com · 03/09/2026

Over the holidays, Zaraz Jadę was born, and it later made its way to the app stores. The project ran until 2022, when my first daughter was born. 👶

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Piotrek Jeremicz @jeremicz.com · 03/09/2026

They say the best #mobile apps are born from a moment of need. #ZarazJade was exactly that kind of story. 📖 Back in 2018, heading home from work on the last day before the holidays... of course three buses in a row just didn't show up. 😤

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Piotrek Jeremicz @jeremicz.com · 02/09/2026

Sounds complicated? Two months ago, I didn't understand any of this myself either. 😅🙌 #LLVM #DevDiary

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Piotrek Jeremicz @jeremicz.com · 02/09/2026

The goal is to implement a new tag from #DWARF 6 that will be a representative of a backing storage. 🧩 I'm currently passing this value from #clang, through #LLVM, all the way down so #LLDB can read it. This way, the `p` won't need to evaluate code - it will read it straight from memory. ⚡

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Piotrek Jeremicz @jeremicz.com · 02/09/2026

dwim-print first tries to read a value straight from memory, and only if that fails does it compile and evaluate through Clang. 🔍 #Swift property wrappers are evaluated today - my task was to make it better. ✨

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Piotrek Jeremicz @jeremicz.com · 02/09/2026

At first I got a simple bug-fix task, but then Augusto offered something way more exciting: working on #LLVM itself, adding a feature to improve the `p` command - `dwim-print` ("Do What I Mean print"). 🚀

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Piotrek Jeremicz @jeremicz.com · 02/09/2026

My mentor in the #SwiftMentorshipProgram is Augusto, who works on the Swift compiler and actively contributes to #LLVM. 🛠️ The program runs 10 weeks and wraps up on September 11 I'm really proud of what I've done. Here's a sneak peek of my goal. ✨ Curious?

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