Calin C. - Senior iOS Developer | Contractor | Freelancer

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Berlin, Germany

Experience

Jan 2022 - Dec 2023

2 years

Senior iOS Developer | Contractor | Freelancer

Gorillas

Groceries and food ordering app delivering the products in minutes.
Successfully migrated 99.9 of the users to the new app by automatically logging them in using the token retrieved from the old app.
Facilitated more than 400k signups in the first 3 months after releasing the redesigned app by supporting phone, Apple, Google, Facebook authentication methods implemented using Firebase.
Helped more than 250k users successfully add their address by supporting search using Google Places and by selecting the exact location using Google Maps based on the service delivery zones.
Firebase Auth, Google Places, Google Maps, Segment, Adjust, Braze, Rich Push Notifications.

Jan 2022 - Dec 2022

1 year

Senior iOS Developer | Contractor | Freelancer

Flash

Instant mobile checkout app entirely implemented in SwiftUI.
Helped the business process over 10 successful orders by implementing an App Clip capable of processing the delivery information using Apple Pay UI and handling the payments using Stripe SDK.
Improved the products loading experience by integrating a caching layer implemented using Core Date and FetchRequest.
SwiftUI, App Clip, Apple Pay, Stripe SDK, GitHub Actions.

Jan 2021 - Dec 2022

2 years

Senior iOS Developer | Contractor | Freelancer

Marquardt Service App

Internal app that helps employees organize their day to day work by digitalizing the entire paperwork process.
Implemented the app from scratch to App Store as the only iOS developer.
Reduced networking traffic by 100% by adding offline support for the main functionality using Core Data and NSFetchedResultsController.
Reduced time spent for creating Firebase and TestFlight builds by 100% by automating the entire build process using Bitrise.
Core Data, NSFetchedResultsController, Diffable Data Sources, Cell Content Configuration, Combine, MapKit, PhraseSDK, Bitrise.

Jan 2020 - Dec 2021

2 years

Senior iOS Developer | Contractor | Freelancer

Yummly

Recipe app that has received the "Editors' Choice" badge from Apple.
Increased monthly business revenue by 12% by redesigning the paywall using modern layout that supports displaying of content using one or two columns depending on the device orientation.
Increased revenue by getting over 10 monthly subscribers that joined on the paywall that I implemented in the existing tvOS application.
Apple IAP, tvOS, SwiftUI, CircleCi, fastlane, git submodules.

Jan 2019 - Dec 2020

2 years

Senior iOS Developer | Contractor | Freelancer

Fortune

Content app that brings Fortune news, newsleters, and videos on mobile at devices.
Increased business revenue from $0 to $10k per month by monetizing the app by adding a $21.99 in-app subscription item that appeared on a screen triggered by an external service depending on the article tags.
Database Design, StoreKit, Travis CI.

Jan 2018 - Dec 2019

2 years

Senior iOS Developer | Contractor | Freelancer

Garmin Pilot

Companion app that connects to various Garmin devices installed on a private airplane.
Dropped user search time from 5-10 minutes to less than 1 minute by designing and implementing a custom search functionality while adding a set of annotation tools using PDFKit.
Improved customer service team efficiency by 40% by reducing the number of daily phone calls by designing and building and in-app feedback system without adding additional server load by automating the email feedback using Firebase Cloud Functions.
PDFKit, Firebase, Build Time Optimization.

Summary

I am a freelancer with 8+ years of experience in iOS development. I help companies around the world implement their mobile solution, focusing on an exceptional user experience.