Sergio Daniel L. García

Senior Mobile & Web Engineer

Medellín, Colombia · Remote-readyme@zheref.io linkedin.com/in/zheref github.com/zheref zheref.io

iOS
Android
React Native
Web
Agentic Delivery

Shipped forStarbucks·Disney·ESPN·Paramount·Citibank·One Medical·Butterfly Network

Profile

Senior engineer with 10+ years shipping products used by millions — Starbucks, Disney, ESPN, Paramount and Citibank among them. Deep on Apple (Swift, SwiftUI, TCA) and fluent on Android (Kotlin, Compose), with production React Native and React/TypeScript work across the same decade, including native modules that make hybrid apps feel first-party. I design architectures that stay clean as they scale and carry them end to end through CI/CD. Two years in, AI agents are a real part of how I deliver — orchestrated, reviewed and tested, not autocompleted. Looking to join a product team full-time.

Skills

Apple platforms

Swift
SwiftUI
UIKit
Combine
Swift Concurrency
TCA
Swift Testing
XCTest
SwiftData
AVFoundation
WidgetKit
Xcode Cloud

Android

Kotlin
Jetpack Compose
Coroutines & Flow
Room
Hilt / Dagger
Retrofit
WorkManager
Material 3
Gradle
Play Console
Kotlin Multiplatform

Web & cross-platform

React Native
TypeScript
React
Redux & Saga
React Query
Node
Gatsby / Astro
Native modules

Agentic AI delivery

Claude Code
Multi-agent orchestration
Spec-driven scaffolding
AI-assisted refactors

Engineering craft

Clean Code & SOLID
Unidirectional Data Flow
TDD / BDD
CI/CD
Accessibility
Observability

Experience

Lead Mobile Engineer at EPAM

Apr 2024 — Apr 2026

Medellín, Colombia · Starbucks (US)

Designed and delivered features for the Starbucks US app in VIPER — robust, testable modules at retail scale.
Introduced AI-assisted developer workflows that automated boilerplate and architectural scaffolding, measurably lifting team velocity.
Drove accessibility compliance and analytics instrumentation, mentored engineers, and set the bar for code review, testing and CI/CD.

Swift
VIPER
TCA
Dependency Injection
Accessibility
Analytics

Lead Mobile Engineer at Gorilla Logic

Jan 2022 — Apr 2024

Medellín, Colombia · CBS / Paramount, Butterfly Network, One Medical by Amazon

Architected iOS features across multiple client products with Swift, SwiftUI, Combine, RxSwift and AVFoundation.
Led a scrum team on augmented-reality and troubleshooting features built on Combine and The Composable Architecture.
Modernized UIKit/RxSwift surfaces to SwiftUI while holding feature parity with Android.

SwiftUI
Combine
TCA
CoreML
LaunchDarkly
Buildkite
SnapshotTesting

Senior Mobile Developer at Making Sense

Jan 2021 — Feb 2022

Remote · Lupl, Citibank

Built Swift/SwiftUI/Combine features for Lupl, plus native React Native modules for analytics and Apple Wallet.
Owned code signing and release distribution for Citibank's ShopYourWay Max, and streamlined test automation, linting and builds across Firebase, GitHub Actions and TestFlight.

Swift
SwiftUI
Combine
React Native
Redux
TestFlight

Lead Mobile Developer at Balance Consulting Group

Jul 2019 — Jan 2021

Remote

Migrated a UIKit/OOP social app to a functional-reactive Combine architecture backed by Firestore.
Architected an iOS/Android infant-monitoring wearable app in React Native with TDD, plus a Fitbit SDK watch face capturing 20+ hours of sensor data.

Combine
Firestore
React Native
Redux
Fitbit SDK
Bitrise
Jest

Lead Mobile Engineer at Kiwibot

Oct 2018 — Aug 2019

Medellín, Colombia

Built the Swift/UIKit iOS app for a robot delivery service in Berkeley, CA, including real-time bot video over Tokbox.
Introduced MVVM + ReactiveCocoa and a server-driven Remote Dynamic Layout for the home screen, and automated build and distribution with Fastlane.

Swift
UIKit
MVVM
ReactiveCocoa
Firebase
Fastlane

Senior iOS Engineer at Globant

Sep 2016 — Nov 2018

Bogotá, Colombia · Disney, ESPN

Disney: ticketing and pass-management workflows — purchases, scheduling, renewals, payments — in a modular CocoaPods/Carthage architecture.
ESPN: server-driven dynamic UI and rich push notifications with media previews, alongside the progressive Objective-C → Swift migration.

Swift
UIKit
TDD
XCTest
CocoaPods
Carthage
CircleCI
TeamCity

iOS Developer at Rappi

Feb 2016 — Sep 2016

Bogotá, Colombia

Re-architected the codebase to VIPER and resolved memory-related crashes and retain cycles with Instruments.
Designed the real-time order-tracking UI reacting to live push updates.

Swift
UIKit
VIPER
Instruments
Auto Layout

iOS & Cross-platform Developer at Skillet · PanamaCOM · Instartius

2010 — 2015

Colombia / Remote

HD recipe-video streaming for iPad (Skillet); high-volume B2B order management and cross-platform wholesale catalogs (PanamaCOM); led a small dev shop delivering web, WPF and mobile solutions (Instartius).

Objective-C
Xamarin
Android / Java
Node
Angular
WPF

Clients

GMV (React Native · MapTiler · Google Maps · Fabric)·SoundsTrue (React Native · Native modules · AVFoundation · HLS)·CNC (Swift · SwiftUI · TCA · CoreData · Bitrise)·Glo (SwiftUI · TCA · HLS · Branch · GitHub Actions)·Very (React Native · Redux-Saga · GraphQL · Apollo)