Ulaş Sancak

🚀 Frontend Architecture Decisions Don’t Break Today — They Break at 18 Months 🧠 In my experience so far as a full stack developer, I’ve seen this pattern play out repeatedly: 📅 Month 1–6: Everything works. Small team. Shared context. High velocity. 📈 Month 6–12: New engineers start joining — they copy patterns without knowing why they exist. Small inconsistencies emerge. 🤔 Month 12–18: Someone finally asks, “Why do we have three different ways to handle API errors?” No one knows — and the person who made the original call left months ago. 💥 Month 18+: Every feature estimate ends with “…but it depends which part of the app we’re touching." 👉 The culprit isn’t bad decisions. It’s undocumented decisions — the ones we thought we’d fix “later.” 👉 What feels slow today — writing docs, ADRs, even just a rationale section in your README — saves 10× more time later. 📌 Key Takeaways for Senior Engineers: ✨ Document decision context, not just the choice itself 📏 Treat architecture as a first-class deliverable — just like features 🤝 Invest early in shared mental models, not just shared code Because code works, but context fades. And when context fades — delivery speed, onboarding, and predictability suffer. #FrontendArchitecture #EngineeringLeadership #SoftwareDesign #DeveloperExperience

4

🚀 Day 9/30 – Testing Strategy in Flutter (What Senior Engineers Do Differently) Most developers write tests. Senior engineers design testing strategy. In interviews, the difference is obvious. 🎯 Why Testing Is a Senior-Level Signal As applications scale: Refactoring becomes frequent Teams grow Releases accelerate Bugs become expensive Without proper testing: Velocity drops. Confidence disappears. Testing is not about coverage percentage. It’s about risk management. 🧠 The 3 Layers of Testing in Flutter 1️⃣ Unit Tests (Foundation) Test: UseCases Business logic Utility classes Repository contracts (with mocks) Fast. Isolated. Deterministic. Example: Dart Code test('login returns user when credentials valid', () async { final mockRepo = MockAuthRepository(); when(mockRepo.login(any, any)) .thenAnswer((_) async => User(id: 1)); final useCase = LoginUseCase(mockRepo); final result = await useCase.execute('email', 'password'); expect(result.id, 1); }); Senior rule: Most business logic should be covered here. 2️⃣ Widget Tests (UI Behavior) Test: UI rendering State changes Interaction behavior Example: Button tap triggers event Error message appears Loading indicator shows Senior rule: Test behavior — not internal implementation. 3️⃣ Integration Tests (End-to-End) Test: Real app flow Navigation API interactions (staging/mock server) Slow but critical. Senior rule: Keep these minimal and focused on critical user journeys. 🏗 Test Pyramid in Practice Senior engineers follow: More unit tests Fewer widget tests Very few integration tests Why? Because: Unit tests are fast and stable Integration tests are slow and brittle Architecture influences testability. If your app is hard to test -> your architecture is wrong. 🔎 What Senior Interviewers Evaluate They don’t ask: “Do you write tests?” They ask: How do you test BLoCs or ViewModels? How do you mock dependencies? How do you structure test folders? How do you ensure regressions are caught? Strong answers include: Constructor injection Repository abstraction Mocking frameworks (mocktail / mockito) CI pipeline integration Test coverage strategy 🔥 Common Testing Mistakes ❌ Testing private implementation details ❌ Writing fragile widget tests ❌ Relying only on manual QA ❌ Avoiding tests due to tight coupling ❌ No separation between UI and business logic 🧠 Professional Takeaway Testing is not extra work. It is architectural validation. If your design follows: SOLID Clean Architecture Dependency Injection Testing becomes natural. If it feels painful -> You have structural issues. #Flutter #FlutterTesting #UnitTesting #WidgetTesting #IntegrationTesting #CleanArchitecture #TechInterview #MobileEngineering #SoftwareQuality #EngineeringLeadership

10

2 Yorum

Temporary fixes create permanent problems. I recently reviewed a codebase where bugs were being “fixed” fast but incidents kept increasing. Nothing was fundamentally broken. Each fix solved the immediate issue. The real problem was patch-driven development. Instead of addressing root causes, the system accumulated: – Conditional logic on top of conditional logic – Silent fallbacks hiding real failures – Tight coupling between unrelated modules – Logic that worked only because everything else stayed the same What changed the system’s behavior: • Removing defensive patches and rewriting the core flow • Defining clear invariants instead of adding checks everywhere • Replacing hidden fallbacks with explicit failures • Simplifying logic paths rather than extending them • Treating root causes, not symptoms Once the shortcuts were removed, the system became predictable not fragile. Speed matters. But clarity outlives speed. Experienced engineers don’t move slower they move in a direction that doesn’t need fixing later.

4