Senior Mobile Engineer | React Native, SwiftUI, UIKit | Madrid, Spain

I'm a Senior Mobile Engineer with 9 years scaling apps for millions of users. At Avios (IAG Loyalty), I led the UIKit -> SwiftUI -> React Native migration for British Airways, Aer Lingus, and Vueling—reducing codebase by 60%, cutting release cycles from 8 to 2 weeks, and enabling 3x faster feature delivery for 1M+ users. I've reduced CI/CD build times by 80%, integrated secure payments (3DS2, Apple Pay), and established TDD practices across teams.

Earlier, I co-founded AccentPOS, building a full-stack POS system with iOS app and payment integrations, which won a 2018 Business Innovation Award. I'm also a 5-star Codementor with 155+ sessions, and recently won 2 hackathons with Moxito, a Web3 fitness rewards app on Farcaster.

I'm currently exploring opportunities where I can combine mobile architecture, team leadership, and emerging tech like Web3, ideally in a remote-first environment.

Available for full-time and contract work | Email | LinkedIn

🏆 $10.5K in hackathon winnings (Moxito)
📱 1M+ users served across airline loyalty apps
⚡ 80% faster CI/CD (40min → 8min builds)
✅ 99.5% crash-free sessions at scale
💬 155+ mentoring sessions with 5/5 stars
🏅 2018 European Innovation Award winner (AccentPOS)

Mobile & Frontend: React Native (Expo), iOS (Swift, SwiftUI), Android (Kotlin), TypeScript, React, Next.js

React Native: Expo, Metro, Hermes, React Navigation, Redux Toolkit, Native Modules.

iOS: Swift 6.x, SwiftUI, UIKit, Objective-C, Core Animation, Core Data, AVFoundation, Combine, async/await, The Composable Architecture (TCA), Xcode Cloud, protocol-oriented programming (POP), MVVM+Coordinator, Cocoapods, Swift Package Manager, Keychain, CallKit, APNs, CoreData, App Tracking Transparency, Privacy Manifest, Deep Linking/Universal Links.

Crypto/Web3: Smart Contracts (Solidity, Hardhat), Wallet Integration (WalletConnect, Metamask SDK), ethers.js, viem, Zero-Knowledge Proofs (Noir), Farcaster SDK

Security and Payments: SSL Pinning, 3DS2 (EMV 3-D Secure), PSD2 SCA, Apple Pay, Apple Wallet, Google Pay, Auth0 OAuth2/OIDC, Secure Enclave, biometric auth, encryption.

Testing and Quality: TDD/BDD, XCTest, XCUITest, Given-When-Then, Jest, Feature Flags, Crashlytics, Firebase, Instruments profiling, Cypress, Charles Proxy.

DevOps and Release: Fastlane, GitHub Actions, CI/CD, App Store Connect, TestFlight, Trunk-based development, Git (rebase/squash/fixups), Docker.

Other: AWS (Lambda, Serverless), NextJS, NodeJS, Supabase, MongoDB, Localization, Accessibility.

SwiftUI • TCA • HealthKit • TestFlight

Farcaster rewards tracking app with privacy-first architecture. Won 2 hackathons on Devfolio.

• 100 TestFlight users in first 3 months
• 1.1K Farcaster followers on launch
• HealthKit integration for activity rewards

View Repository • Case Study

https://www.codementor.io/@christian.leovido

Avios (IAG Loyalty) - British Airways, Aer Lingus, Vueling loyalty apps

• Led UIKit → SwiftUI → React Native migration
• Integrated payment providers and secure authentication
• Established TDD/BDD practices with XCTest

AccentPOS - Full-stack POS system (Co-founder)

• iOS app, Node.js backend, real-time sync
• Payment integrations (Star Micronics, Paymentsense, EVO)
• Won 2018 Business Innovation Award

Luzia AI - Consumer iOS app

• Google Ads SDK integration
• High-impact bug fixes with test coverage

SwiftUI • MVVM • Combine • async/await
Star Wars planet browser showcasing modern iOS patterns. Take-home exercise that landed me the Luzia job.

The Composable Architecture • SwiftUI • SPM
Finance demo with modular architecture. Take-home that got me an offer from "Much Better".

Pure Functions • Monads • State Management
Swift port of "13 Ways of Looking at a Turtle" from F#. Exploring functional patterns in iOS.

Zero-Knowledge Proofs • Farcaster Protocol
Anonymous Farcaster client using Noir ZK proofs.

• Codementor: 5/5 rating, 85+ sessions, 155+ mentoring sessions
• AWS Certified: Cloud Practitioner, AI Practitioner
• Active contributor to iOS and web3 ecosystems

Exploring: Farcaster protocol, React Native architecture patterns, modern iOS development
Available for: Senior Mobile Engineer roles (Madrid/Remote EU) and contract iOS/React Native work
Looking for: Product-focused teams that value quality, trunk-based development, and building products users love

Let's connect: LinkedIn • Twitter • Farcaster

📍 Madrid, Spain | 🌍 Open to remote opportunities | 💼 Available for immediate work