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Kasper Welner

Senior iOS developer
  • Ideal project length 1-3/3-6 months
  • Location Remotely (meetings possible)
  • Available from 1st August

I have more than 7 years experience in software development, mainly centered around iOS application development. I am also experienced in team management and new hirings as well as technical guidance and mentoring. 

I have been involved in all steps needed to produce an app, ranging from idea development, project management to team management. I have personally uploaded over 35 apps to the Apple App Store. Portfolio listed below contains only some highlights of my work.

  • iOS
  • MacOS
  • Vapor
  • UX
  • XCode
  • Photoshop
  • Sketch
  • Git
  • Jenkins
  • Fastlane
  • App Store
  • Swift
  • Obj-C
  • C
  • C++
  • JavaScript
  • Ruby
  • C#
  • Python
  • Core Data
  • Core Audio
  • Game Kit
  • Core Bluetooth
  • Core Location
  • REST
  • Realm
  • Rx
  • OpenGL
  • ZeroMQ
  • Google Protocol Buffers
  • TCP sockets
  • HMAC
  • Cocos2D

Senior iOS Developer

Codeum ApS, Copenhagen · 2016 - 2018

Spec, UX and implementation of iOS client of a new betting platform, built from scratch. 

▸ The app is focused on low latency and high security which was obtained using ZeroMQ, Google Protocol Buffers, HMAC-SHA256, Realm and AsyncDisplayKit

ZeroMQ Google Protocol Buffers HMAC-SHA256 Realm AsyncDisplayKit

iOS Lead

Nodes ApS, Copenhagen · 2013 - 2016

Led a team that grew to 13 junior to senior developers across Copenhagen and London, while still actively developing iOS applications 70% of my time. 

Responsibilities included: 
▸ Hiring, mentoring and reviewing team members as well as negotiating salaries with them 
▸ Enforcing best practices and improving efficiency by streamlining internal code conventions 
▸ Driving team transition from Swift to Objective-C 
▸ Time-estimation of projects 

Selected key projects:

▸ The system through which all information from governmental and financial institutions is being sent to DK citizens. 2+ million App Store downloads. 

Børsen News, Børsen Play (Biggest financial newspaper in Denmark)
▸ Featured layout engine for dynamically displaying content received from server 
▸ Custom video player (built on AVFoundation) with minimizable video view like the YouTube app. Also displays sync’ed information on top of video. 

Tattoodo (world’s largest tattoo community) 
▸ Elaborate custom UI transitions 
▸ Image processing with brightness and contrast controls using CoreImage

▸ Implemented a clone of Instagram, complete with feed, mentions, hashtags, image filters etc.
▸ Image filters were implemented using CoreImage

Objective-C Corelmage Swift iOS

iOS Developer

Nodes ApS, Copenhagen · 2012 - 2013

Joining a team of 3 iOS developers, I worked on 30+ apps. I was technical lead on the majority of the projects, which among other things included: Writing API spec for backend developers, making sure technical possibilities were synced across platforms for consistency, being single entry-point for Project Managers, flagging any potential time-sinks not accounted for in estimations and choosing appropriate technologies for the task. 

Selected projects:

Hamlet-Aleris Private Hospital, iOS (Unavailable)
▸ The app enabled women to take a picture of themselves and subsequently adjust some controls to see how they would look after a breast augmentation operation.

Schweppes Moments
▸ The app enabled people to upload short 5-second videos shot in the app. 6 different filters could be applied to the video clips.

Blossa Worlds’ Biggest Choir (Backend)
▸ Wrote a command line script using SoX that was run every day to process and mix the recording of 10-100 new user generated recordings of users singing the Blossa theme song in order to create “The World’s Biggest Choir”.

Tuborg Coin App, Marabou, iOS 
Augmented Reality, but in 2012

YouSee, Telmore iOS
▸ Self-service apps for 2 of Denmark’s biggest phone companies

Swift iOS

Freelance work

2011 - 2018

Selected projects:

4Sound app, 2011-2012, iOS (Unavailable)
▸ Built an iOS app for Danish music retail shop 4Sound. Included a full e-shop with product browsing and checkout, news/article section and user forum.

Robeat Boys Platform Game, 2015, iOS
▸ As a promo for the release of Danish Electro Duo Robeat Boys’ single Never Take You Back I built a small 2D Platform shooter. I created my own game engine using OpenGL and custom physics for the game. 

Heartbeats sales tool, 2018, Backend (Vapor), Web Frontend
▸ For Danish media agency Heartbeats, I have built a REST API for an internal sales tool app. It features a complex company and user management system. I also built a

JavaScript iOS OpenGL Vapor

Rytmisk Musikkonservatorium, Denmark

Copenhagen - 2003 - 2008

Master's degree

Driving licence
English (Fluent) German (Basic) Danish (Native)

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