Product: m10 - mobile wallet/payments super-app — transfers, cards, KYC. Scale: 3M+ installs, ~100k DAU. https://play.google.com/store/apps/details?id=com.m10&hl=en https://apps.apple.com/az/app/m10-digital-wallet/id1642308007 International transfers w2w/w2c/c2w: FX rates, fees, statuses, beneficiary catalog, validations and error UX; resilient flows under network issues. KYC + Face Recognition: liveness/face match, document capture, secure PII handling; session_manager and device control. Payments: Google Pay / Apple Pay, 3DS 2.x, card tokenization, graceful fallbacks; multi‑provider compatibility. Virtual cards (Mastercard): issuance, (un)freeze, limits, reissue, tokenization to wallets. Client security: device binding, jailbreak/root detection, certificate pinning, R8/ProGuard obfuscation, anti‑fraud safeguards. Remote updates / feature flags: staged rollouts, kill‑switch, country‑specific configs; A/B testing. OCR/HTR for bills/receipts: handwritten text recognition, extraction of amount/payee/purpose, auto‑fill and validations. LLM analytics & assistant: natural‑language insights (e.g., “where do I spend most?”), budgeting; voice commands for bill payments/transfers with biometric/PIN confirmation; guard‑prompts and PII redaction. Reliability & performance: reduced cold‑start, memory/IO optimizations, improved crash‑free rate; SLO/metrics monitoring, covered code with unit, widget, golden, e2e, integration tests. CI/CD: build/test/release pipelines (GitHub Actions/Fastlane), code signing, release tracks/environments; testing pyramid unit/widget/integration/e2e.

Product: P2P messenger - cross-platform real-time messenger (mobile/desktop), E2E-ready. Scale: ~400k+ installs, ~10k DAU. Networking core: shared C++ library for mobile/desktop, WebSocket/TLS 1.3 with keep‑alives/heartbeats, binary framing (Protocol Buffers), multiplexed channels (chat/presence/media). Real‑time robustness: exponential jitter backoff, outbox queue with idempotency (dedupe keys), at‑least‑once delivery guarantees, message‑type QoS levels. Search & storage: local DB (Room), WAL, indexes, FTS for fast message search; sync markers and retention policies. Multi‑device sync: vector clocks (Lamport), conflict resolver (LWW + merge), server ACKs/causality checks; clock‑skew recovery. E2E‑ready cryptography: session keys, rotation, forward secrecy; AES‑GCM at rest, secure media cache. Media pipeline: chunked uploads with resumable protocol, on‑device compression, thumbnails (ffmpeg), CDN links and lazy‑fetch. Push bridge: FCM/APNs, silent push for background sync; deep links, QR invites. Quality: integration/e2e for delivery/retries/offline, protocol fuzzing, stability soak tests.

Product: Plazo - consumer fintech app — payments, P2P, cards/limits, 3DS. Scale: 2M+ installs, ~30k DAU. Payment flows: 3DS 2.x (frictionless/challenge), timeouts/retries, idempotent requests, refunds/rollbacks, double‑charge protection. P2P & cards/limits: validations, FX/fee calculation, status rendering, robust edge‑case handling (poor network/double taps). Integrations: external KYC/AML providers, payment SDKs, push/deep links, analytics event taxonomy and funnels. Reliability: circuit breaker, graceful degradation, local send queues; improved cold‑start and reduced UI jank. Privacy/security: secure storage, device binding, PAN/PII masking, no on‑device storage of sensitive card data. Quality/process: unit/widget/integration/e2e, API contract tests (OpenAPI), provider mock hubs, CI/CD (lint/build/release), feature flags/remote config.

Product: German digital‑health app: rapid lab test ordering (nearest locations, free slots), e‑voucher/QR codes, real‑time statuses (collection → processing → result). Scale: 100k+ installs, ~1k DAU. Patient portal: results tracking, trend charts, re‑test reminders, export to PDF/CSV. AI modules: auto‑insights on results (reference ranges, deviations/risk flags), basic symptom checker (opt‑in). Integrations: Apple Health / Google Fit, wearables (heart/sleep/activity), clinician recommendations. Privacy & security: GDPR/DSGVO, consent & data minimization, PHI encryption (at rest/in transit); offline mode and deferred sync. Quality & process: CI/CD, Crashlytics/Sentry, performance profiling, unit/widget/integration tests, pilots via MDM/TestFlight/Closed Track.

Android project (native): Event Ticketing & Wallet Passes Scale: 400k+ installs, ~2k DAU Ticket lifecycle: purchase/import, seat maps with pinch-zoom and section highlights, promo codes, refunds; add-to-Google Wallet passes with server-driven updates and expiry handling. Entry experience: rotating QR tokens (time-boxed), optional NFC tap where supported, offline validation window, auto brightness boost and anti-screenshot watermarks. At-venue UX: interactive venue maps, gate/section wayfinding, geofenced reminders for gate opening, push alerts for schedule/lineup changes; deep links straight to event/passes. Reliability & offline: cached passes/events, background sync with WorkManager, idempotent updates/retries; in-app updates for hotfixes; dynamic feature delivery to keep APK size small. Quality & security: Play Integrity API, device binding to passes, root detection; Crashlytics/Sentry dashboards, A/B experiments

Product: Lastmile - courier/last-mile app — scanning, PoD, routing/ETA. Barcode/QR scanning, Proof‑of‑Delivery (photo/signature), task status tracking. Offline‑first: local cache, sync queues, conflict resolution. Maps & logistics: routing, ETA, geofencing, background location/batching. Observability: Crashlytics/Sentry, tracing of critical flows, performance profiling. CI/CD & testing: unit/widget/integration tests, internal distribution (MDM/TestFlight/Closed Track).

Product: DerivGO - retail trading app — real-time quotes, orders, charts. Real‑time quotes (WebSocket), charts (candles/indicators), order book/order flow. Risk & orders: limits, pre‑calculation of fees/margin, validations, trade notifications. Real‑time stability: reconnect, debounce/throttle, duplicate‑event protection. Security: 2FA/biometrics, session hardening. Unit/integration tests, exchange session simulator, CI/CD.