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

▶️ 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

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

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

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

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

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

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

Highly recommend #SwiftMentorshipProgram to everyone! A great chance to do something different. 🙌 #Swift is a really approachable language, and #Xcode - despite the complaints - is a friendly #IDE. 🛠️ You really feel it once you sit down with a huge C project like #LLVM. 😅

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Piotrek Jeremicz @jeremicz.com · 01/09/2026

It's been a while since I posted here. Haven't written anything in ages. Social media can be such a time-eater, but it also gives you space to express yourself. I've cut back on reading, but I miss writing - and I've got plenty to write about. 📝

A vibrant rainbow arch stands in a grassy area with wooden picnic tables and umbrellas, suggesting a lively outdoor setting.

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Piotrek Jeremicz @jeremicz.com · 04/08/2026

I’m not a morning guy… Unless I’m taking a train - then it’s okay… 😇

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Piotrek Jeremicz @jeremicz.com · 27/07/2026

After 9 months, three attempts, over 12 million tokens, and a bunch of crises, I’ve done it! 😲 #ZarazJade - with a fully refactored architecture - is ready for its new journey... Almost four years it took to rebirth this project... 😅 Now... I’m going to sleep... 🥳

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Piotrek Jeremicz @jeremicz.com · 20/07/2026

#SwiftMentorshipProgram - Step by Step 🚶‍♂️ The first week of the program was fully immersed in the giant swift-lang repository. I ran some tests, broke the code, and tried a few hacks. 🧰

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Piotrek Jeremicz @jeremicz.com · 17/07/2026

I’m trying so hard not to postpone the update of #ZarazJade after the refactor. But every day I add more fixes - this is the biggest trap... There’s just one last thing to verify, and then I’m sending it for review. Keep your fingers crossed. One thing... Subscriptions...🐱

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Piotrek Jeremicz @jeremicz.com · 17/07/2026

The whole system is slowly coming back online. 🚀 It was a mega-productive night 🌙, but now I have to wait patiently for the results. ⏳ #ZarazJade comes to life! 🎉

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Piotrek Jeremicz @jeremicz.com · 15/07/2026

After 9️⃣ months of heavy dev, hundreds of PRs, thousands of lines of Swift, and a million tokens, I can finally create the first release... 🚀 #ZarazJade will be handled by the global brand AboutToGo, which - I hope - will help me expand into foreign markets. Now, it’s time to release! 🥳

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Piotrek Jeremicz @jeremicz.com · 10/07/2026

Preparing for tomorrow! 👨‍💻

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

Excited to share that I'll be speaking at the Swift Surat Online Meetup this Saturday! 🎉 I'll be diving into SwiftUI data flow - covering @State, @Binding, and going a step further into Environment, Preference and Container Values. 📅 11th July, 4-6 PM IST 👉 Register here: luma.com/zonymtk9

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Piotrek Jeremicz @jeremicz.com · 08/07/2026

#SwiftMentorshipProgram - The Goals ☑️ My first mentor meeting was on Monday. We introduced ourselves, talked through my goals, and planned the first steps. A mentor isn't a teacher. They help you get started, prepare materials, and define your first task. The rest is on you! 👷‍♂️ #DevDiary

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Piotrek Jeremicz @jeremicz.com · 08/07/2026

#SwiftMentorshipProgram - Build Time! 🏗️ The build time for the Swift Compiler is... almost half an hour on an M5 Pro. The directory grows 10x - to almost 100GB! That’s the same #Swift Compiler we use every day in #Xcode. Absolute unit! 🫨 ➡️ Next: getting the IDE ready to navigate all this C++.

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Piotrek Jeremicz @jeremicz.com · 08/07/2026

#SwiftMentorshipProgram - Cloning That’s exciting for me, maybe because cloning the #Swift Compiler code feels like another circle of initiation after the classic question: "How does Optional work under the hood"... 🤪 But it’s not only #SwiftLang, there are 53 additional sibling repos! 📦 #DevDiary

A terminal window shows a Git command in progress for cloning the Swift programming language repository, indicating the cloning status and progress.

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Piotrek Jeremicz @jeremicz.com · 08/07/2026

#SwiftMentorshipProgram - Getting Swift... ...but not in the form we all know. Today I installed all the dependencies required to build the #Swift compiler. You need Xcode, cmake, ninja, ccache, git, and python3. 👨‍💻 I was most impressed by the requirements! 150GB! 😱 #DevDiary

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

Looking for indie mobile developers from CEE 🌍 (Poland, Czechia, Slovakia, Hungary, Baltics, Ukraine and beyond). If you're building something cool on iOS 📱, let me know - would love to connect! 🤝

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Piotrek Jeremicz @jeremicz.com · 06/07/2026

#SwiftMentorshipProgram - Week 1 🚀 Today, the 10-week cohort starts! Pairings have been announced and first goals have been written down - let the contribution begin! If you are curious, follow me. I'll keep you updated on my progress. Today is the first meeting with my mentor. 🤝

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Piotrek Jeremicz @jeremicz.com · 03/07/2026

I’ve run 6 agents on the Claude Fable #model. Only two audits made sense: backend and security. The rest produced AI slop, with just a few minor useful bullet points. MySQL, iOS, architecture, and cost optimization all failed to deliver any important highlights. So... devs are still needed!

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Piotrek Jeremicz @jeremicz.com · 02/07/2026

I'm starting to feel the pressure...

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Piotrek Jeremicz @jeremicz.com · 01/07/2026

I'm very excited to share that I'll be taking part in the Swift Mentorship Program! 🥳 As developers, we're always asking how Swift works under the hood. Now I get to look even deeper and help shape the language I love. 👨‍💻 Super hyped! 🚀 #Swift #SwiftLang #Mentorship

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