https://juxtalux.com.br/blog/en/ Practical guides and engineering notes from a Brazilian app studio. en Wed, 12 Aug 2026 00:00:00 +0000 https://juxtalux.com.br/assets/logo.png https://juxtalux.com.br/blog/en/ https://juxtalux.com.br/blog/en/why-one-game-is-godot.html https://juxtalux.com.br/blog/en/why-one-game-is-godot.html Four of the studio's games are Flutter. One is Godot 4.3, and it was not a whim: a platformer with hand-drawn levels needs a scene editor. What switching tools actually cost. Wed, 12 Aug 2026 00:00:00 +0000 EngineeringGames https://juxtalux.com.br/blog/en/the-video-title-kept-reverting-to-the-filename.html https://juxtalux.com.br/blog/en/the-video-title-kept-reverting-to-the-filename.html We typed the title, saved, and YouTube gave us back 'jornada 01 cena s s usuario abre o 1'. It took seven videos to find out these were two different bugs, not one. Wed, 12 Aug 2026 00:00:00 +0000 Organic marketingEngineering https://juxtalux.com.br/blog/en/the-post-looked-published-and-did-not-exist.html https://juxtalux.com.br/blog/en/the-post-looked-published-and-did-not-exist.html It took 14 hours to find out Reddit's spam filter had swallowed our first post — and it still looked normal on our own screen. What we learned about account and domain reputation. Wed, 12 Aug 2026 00:00:00 +0000 Organic marketingProduct https://juxtalux.com.br/blog/en/offline-first-with-drift-and-sqlite.html https://juxtalux.com.br/blog/en/offline-first-with-drift-and-sqlite.html RodaGrana computes a rideshare driver's real profit with no back end at all. That is not a limitation — it is the right architecture for the problem. What changes when you take the server out of the equation. Wed, 12 Aug 2026 00:00:00 +0000 EngineeringFlutterOffline https://juxtalux.com.br/blog/en/moderating-memes-with-ai-before-publishing.html https://juxtalux.com.br/blog/en/moderating-memes-with-ai-before-publishing.html In EuRi a Cloud Function calls Gemini the moment a post is created, and content only goes live if it passes. What that inversion cost in latency, false positives and product complexity. Wed, 12 Aug 2026 00:00:00 +0000 EngineeringAI https://juxtalux.com.br/blog/en/kids-games-what-to-check-before-installing.html https://juxtalux.com.br/blog/en/kids-games-what-to-check-before-installing.html The store listing says more than the game description. Four fields answer what an app collects, what it charges and how much it interrupts — and why 'free' is rarely the right word. Wed, 12 Aug 2026 00:00:00 +0000 PrivacyGamesProduct https://juxtalux.com.br/blog/en/game-economy-that-runs-on-the-server.html https://juxtalux.com.br/blog/en/game-economy-that-runs-on-the-server.html Eighteen minigames, rewards, a global leaderboard and withdrawals — and no value decision made on the client. The main reason has less to do with cheating than you would expect. Wed, 12 Aug 2026 00:00:00 +0000 EngineeringGames https://juxtalux.com.br/blog/en/flame-or-plain-widgets.html https://juxtalux.com.br/blog/en/flame-or-plain-widgets.html Not every Flutter game needs an engine. Of our five, two use Flame, two run on plain widgets and one left Flutter entirely. The criterion that separates the cases is simpler than the debate suggests. Wed, 12 Aug 2026 00:00:00 +0000 EngineeringFlutterGames https://juxtalux.com.br/blog/en/fixed-coordinates-are-technical-debt.html https://juxtalux.com.br/blog/en/fixed-coordinates-are-technical-debt.html A time picker that jumps three hours per click, a toolbar that moves when the text wraps to a second line, a window that resizes on its own. Every publishing failure had the same root cause. Wed, 12 Aug 2026 00:00:00 +0000 Organic marketingEngineering https://juxtalux.com.br/blog/en/fifteen-thousand-lines-in-one-main-dart.html https://juxtalux.com.br/blog/en/fifteen-thousand-lines-in-one-main-dart.html One of our apps has a single file with more than fifteen thousand lines. It shipped, it works and it pays bills. An honest account of what that choice gave us, what it cost, and when it stops being viable. Wed, 12 Aug 2026 00:00:00 +0000 EngineeringFlutter https://juxtalux.com.br/blog/en/eight-apps-nineteen-channels.html https://juxtalux.com.br/blog/en/eight-apps-nineteen-channels.html The honest scoreboard of an organic marketing push: four channels at 100%, five at zero, and one unchecked assumption that left 47 videos live with the wrong text. Wed, 12 Aug 2026 00:00:00 +0000 Organic marketingProduct https://juxtalux.com.br/blog/en/anonymous-questions-can-you-find-out-who-sent-it.html https://juxtalux.com.br/blog/en/anonymous-questions-can-you-find-out-who-sent-it.html The short answer is no — and anyone promising otherwise is selling an illusion or harvesting your data. The long answer explains what the app knows, what it does not, and what to do about abusive messages. Wed, 12 Aug 2026 00:00:00 +0000 ProductPrivacy