Mobile Application Developer

K&K Social Resources & Development GmbH is an international recruiting agency that has been providing technical resources in the European region since 1993. This position is with one of our clients in Bulgaria, who is actively hiring candidates to expand their teams.Job Role: Mobile Application DeveloperLocation: Sofia, BulgariaTechnology; iOS/Android Development (Kotlin - Android, Swift - iOS, Java, Python, Node.js.)Employment Type: PermanentDescription:Job DescriptionYour roleWe’re seeking a client‑facing Senior Associate Consultant – Android / iOS Developer who can deliver end‑to‑end Android/iOS app solutions – from discovery and architecture through development, release, production reliability and lead analytics & attribution implementation with Kochava. You’ll architect, build, and ship high‑quality Kotlin/Swift apps, integrate Kochava SDKs and privacy flows, and own Incident & Problem Management, analytics reliability, and deep debugging in production. If you love crafting performant, resilient, and measurable mobile experiences, this role is for you.Must Have:Android Engineering (End‑to‑End Delivery)4–6 years of professional development experience, with 2+ years building and shipping native Android/iOS apps at scale.Design and develop native Android apps using Kotlin and Java, Jetpack (Compose/XML, Navigation, WorkManager, Room/DataStore), Coroutines/Flow, and Hilt/Dagger.Implement robust networking (Retrofit/OkHttp, GraphQL), caching, offline sync, background processing, App Links/Deep Links, and in‑app updates/review.Build clean, testable architecture (modularization, MVVM/Clean, feature modules) and maintain multi‑flavor/variant configurations with Gradle (KTS).Manage releases via Play Console (tracks, staged rollouts, pre‑launch reports) and CI/CD (Gradle, Fastlane, Bitrise/GitHub Actions/Jenkins).Kochava Analytics & AttributionIntegrate and configure the Kochava Android/iOS SDK: initialization, consent‑aware tracking, event taxonomy, audience/identity configuration.Implement attribution use cases: install & re‑engagement attribution, deferred deep links, campaign parameters (UTM), push token tracking.Configure and ensure privacy alignment: Google Play (Android play store) Install Referrer, Advertising ID handling (respect user limits), App Set ID, consent frameworks (IAB TCF), and Data Safety disclosures.Configure and ensure privacy alignment: SKAdNetwork (iOS play store) support (conversion value strategy, postback handling, testing) and align with ATT consent flows.Define analytics requirements with Product/Marketing; map custom events/properties, validate data pipelines, and reconcile metrics across Kochava and in‑app analytics (e.g., Firebase).Quality, Security & ComplianceEnforce quality gates (Android): JUnit/MockK, Espresso/Compose UI tests, snapshot tests, static analysis (Detekt, ktlint), and code coverage targets.Enforce quality gates (iOS): XCTest/XCUITest, snapshot tests, code coverage targets, static analysis (linting), and secure coding practices.Implement secure storage (Android Keystore, EncryptedSharedPreferences), TLS best practices, and tamper/jailbreak detection as appropriate.Ensure privacy & compliance: iOS ATT prompts, consent management integration, data minimization, and privacy disclosures.Ensure compliance with Google Play / Apple Store policies, Data Safety, and regional privacy laws (GDPR/CCPA).Participate in Change Enablement/CAB, keep rollback/kill‑switch plans ready, and maintain auditable build/release artifacts.Analytics, Observability & Deep DebuggingAndroid Instrument crash & performance monitoring (Firebase Crashlytics, Android Vitals, Sentry) with dashboards for SLIs/SLOs (crash‑free users %, ANR %, cold start p95, network error rate).Apple iOS Instrument crash & performance monitoring (e.g., Crashlytics/Sentry/Xcode Metrics) with dashboards for SLIs/SLOs (crash‑free users %, cold start p95, network error rate).Perform deep debugging and performance profiling with Android Studio Profiler, LeakCanary, Perfetto/Systrace, StrictMode, ADB/Logcat, Network Inspector.Use Xcode Instruments (Time Profiler, Allocations, Leaks, Network, Energy), LLDB, os_log/Unified Logging, and Console for deep iOS debugging.Verify attribution/analytics correctness using Kochava test utilities, Install Referrer tests, and HTTP proxies (Charles/Proxyman).Nice to Have:Knowledge and experience with Mobile Development (Swift, SwiftUI, Objective C), Flutter and iOS SDK.Familiar with 3rd part libraries and their integration into iOS/Android applications.Knowledge of Mobile Security Practices (SSL Planning)Familiar with Android/iOS Release processes.Additional analytics exposure (Firebase Analytics/GA4, Amplitude/Mixpanel) and data tools (BigQuery/SQL).Experience with feature flags/remote config (Firebase RC, LaunchDarkly) and A/B testingPayments/subscriptions (Billing Library), Play Integrity, Feature Delivery, and app modularization at scale.Networking hardening (retry/backoff, caching, offline strategies) and Edge/CDN awareness. Secure payments and in‑app purchases, App Store Server APIs, and receipt validation.Datastores: Core Data, Realm; background processing and Background Tasks.Cloud/mobile backends (Firebase, AWS Amplify), push providers, and CI mobile distribution at scale.Knowledge of Source Control (GIT), Sniffers (Charles) and project Management tools (Jira/Confluence/TFS).Note: Applicants for employment in Bulgaria should possess work authorization which does not require sponsorship by the employer for a visa.