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

iOS Swift

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

iOS OpenGL Vapor JavaScript

Rytmisk Musikkonservatorium, Denmark

Copenhagen - 2003 - 2008

Master's degree

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

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