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Jens Hagfeldt

Upplands-Väsby, Sweden

Open to Work

My name is Jens Hagfeldt, I'm an Developer (iOS and Web) with a background of 23+ years, working as a preschool-teacher. It is with great anticipation I now look forward on working as a Developer for at least as many years.

16,548

Total Points

•
1,081

Android

1080 pts
Achievements

1 pts
Forum
•
868

HTML

868 pts
Achievements

0 pts
Forum
•
564

CSS

564 pts
Achievements

0 pts
Forum
•
525

Design

525 pts
Achievements

0 pts
Forum
•
307

JavaScript

307 pts
Achievements

0 pts
Forum
•
217

Ruby

217 pts
Achievements

0 pts
Forum
•
67

Business

67 pts
Achievements

0 pts
Forum
•
54

C#

54 pts
Achievements

0 pts
Forum
•
44

Development Tools

44 pts
Achievements

0 pts
Forum
•
2

Python

2 pts
Achievements

0 pts
Forum
•
1

Java

1 pts
Achievements

0 pts
Forum
•
1

PHP

1 pts
Achievements

0 pts
Forum

Points are earned whenever you take an important action on Treehouse.
Learn more about when and how points are earned.

Skills & Experience

Job Title

Developer (iOS & Web)
Spoken Languages
- Swedish, English
- English

219 Achievements

Achievement
Introduction to Video Games

How to Make a Video Game

Achieved
Apr 14, 2017
Achievement
Adding Sound Effects

Build an Interactive Story App with Swift

Achieved
Feb 19, 2017
Achievement
Personalizing The Story

Build an Interactive Story App with Swift

Achieved
Feb 19, 2017
Achievement
Refactoring Our Code

Build an Interactive Story App with Swift

Achieved
Feb 19, 2017
Achievement
Creating the User Interface Programmatically

Build an Interactive Story App with Swift

Achieved
Feb 19, 2017
Achievement
Creating a Story

Build an Interactive Story App with Swift

Achieved
Feb 18, 2017
Achievement
Navigating Through An Adventure

Build an Interactive Story App with Swift

Achieved
Feb 18, 2017
Achievement
Introduction to Unit Testing

Unit Testing in iOS

Achieved
Jan 14, 2017
Achievement
Introduction to Collections

Swift Collections and Control Flow

Achieved
Nov 25, 2016
Achievement
Swift Operators

Swift Basics

Achieved
Nov 25, 2016
Achievement
Swift Types

Swift Basics

Achieved
Nov 21, 2016
Achievement
An Introduction to Swift Programming

Swift Basics

Achieved
Nov 17, 2016
Achievement
Adding Metadata to Photos

Build a Selfie App with Swift 2

Achieved
Sep 8, 2016
Achievement
Adding Image Filters

Build a Selfie App with Swift 2

Achieved
Sep 7, 2016
Achievement
Taking a Selfie

Build a Selfie App with Swift 2

Achieved
Sep 5, 2016
Achievement
Introduction to CollectionViews

Displaying API Data with Collection Views in Objective-C

Achieved
Aug 10, 2016
Achievement
Deleting and Updating Data

Introduction to Core Data with Swift 2

Achieved
Jul 26, 2016
Achievement
Fetching Data Using Fetch Requests

Introduction to Core Data with Swift 2

Achieved
Jul 26, 2016
Achievement
Inserting and Saving Data Using a Context

Introduction to Core Data with Swift 2

Achieved
Jul 26, 2016
Achievement
Understanding the Core Data Stack

Introduction to Core Data with Swift 2

Achieved
Jul 25, 2016
Achievement
Paged Scrolling

Introduction to Scroll Views with Swift 2

Achieved
Jul 21, 2016
Achievement
Understanding Scroll Views

Introduction to Scroll Views with Swift 2

Achieved
Jul 21, 2016
Achievement
Media Basics

HTML Video and Audio (Retired)

Achieved
Jul 12, 2016
Achievement
Structuring Tables

HTML Tables

Achieved
Jul 12, 2016
Achievement
Implementing Maps and Search

Displaying Data with Table Views in Swift 2

Achieved
Jul 12, 2016
Achievement
Obtaining a Location Fix

Displaying Data with Table Views in Swift 2

Achieved
Jun 29, 2016
Achievement
Displaying Data in Table Views

Displaying Data with Table Views in Swift 2

Achieved
Jun 26, 2016
Achievement
Enhancing the Networking Stack

Displaying Data with Table Views in Swift 2

Achieved
Jun 22, 2016
Achievement
URLs and Parameter Encoding

Displaying Data with Table Views in Swift 2

Achieved
Jun 20, 2016
Achievement
Introduction to UITableView

Displaying Data with Table Views in Swift 2

Achieved
Jun 20, 2016
Achievement
Implementing a Forecast Client

Network Programming with Swift 2

Achieved
Jun 19, 2016
Achievement
Protocol Oriented Networking

Network Programming with Swift 2

Achieved
Jun 14, 2016
Achievement
Fetching Data From the Web

Network Programming with Swift 2

Achieved
Jun 13, 2016
Achievement
Modeling Forecast Data

Network Programming with Swift 2

Achieved
Jun 13, 2016
Achievement
Asynchronous Error Handling

Closures in Swift 2

Achieved
Jun 13, 2016
Achievement
Closures in Cocoa Touch

Closures in Swift 2

Achieved
Jun 13, 2016
Achievement
Building Standard Library Functions

Closures in Swift 2

Achieved
Jun 12, 2016
Achievement
Closure Expressions

Closures in Swift 2

Achieved
Jun 10, 2016
Achievement
First Class Functions

Closures in Swift 2

Achieved
Jun 10, 2016
Achievement
Visual Format Language

Introduction to Auto Layout in iOS

Achieved
Jun 1, 2016
Achievement
Auto Layout in Code

Introduction to Auto Layout in iOS

Achieved
Jun 1, 2016
Achievement
Trait Collections

Introduction to Auto Layout in iOS

Achieved
May 27, 2016
Achievement
Inequalities, Content and Priorities

Introduction to Auto Layout in iOS

Achieved
May 27, 2016
Achievement
The Constraint Equation

Introduction to Auto Layout in iOS

Achieved
May 27, 2016
Achievement
A History Lesson

Introduction to Auto Layout in iOS

Achieved
May 27, 2016
Achievement
Generics with Swift 2 - Beyond Basics

Generics in Swift 2

Achieved
Apr 29, 2016
Achievement
Generics with Swift 2

Generics in Swift 2

Achieved
Apr 29, 2016
Achievement
Singletons

iOS Design Patterns

Achieved
Apr 18, 2016
Achievement
Adding Sound Effects

Build an Interactive Story App with Swift 2

Achieved
Apr 7, 2016
Achievement
Refactoring the Model

Build an Interactive Story App with Swift 2

Achieved
Apr 7, 2016
Achievement
Creating the User Interface Programmatically

Build an Interactive Story App with Swift 2

Achieved
Apr 6, 2016
Achievement
Creating a Story

Build an Interactive Story App with Swift 2

Achieved
Apr 6, 2016
Achievement
Navigating Through an Adventure

Build an Interactive Story App with Swift 2

Achieved
Apr 5, 2016
Achievement
Memory Management in Swift 2

Intermediate Swift 2

Achieved
Apr 5, 2016
Achievement
Extensions and Protocols

Intermediate Swift 2

Achieved
Apr 4, 2016
Achievement
Value Semantics, Type Methods and Inheritance

Intermediate Swift 2

Achieved
Apr 4, 2016
Achievement
Object Initialization in Swift 2

Intermediate Swift 2

Achieved
Apr 3, 2016
Achievement
Properties in Swift 2

Intermediate Swift 2

Achieved
Apr 1, 2016
Achievement
Displaying Additional Views

Build a Vending Machine App in Swift 2.0

Achieved
Feb 24, 2016
Achievement
Using the Vending Machine

Build a Vending Machine App in Swift 2.0

Achieved
Feb 24, 2016
Achievement
Loading Data From a Resource

Build a Vending Machine App in Swift 2.0

Achieved
Feb 23, 2016
Achievement
Modeling An Interface

Build a Vending Machine App in Swift 2.0

Achieved
Feb 22, 2016
Achievement
Two-stage Object Creation

iOS Design Patterns

Achieved
Feb 4, 2016
Achievement
What Are Design Patterns?

iOS Design Patterns

Achieved
Feb 4, 2016
Achievement
Error Handling in Swift 2.0

Error Handling in Swift 2.0

Achieved
Jan 19, 2016
Achievement
Creating Flexible Objects Using Protocols

Swift 2.0 Protocols

Achieved
Dec 27, 2015
Achievement
Swift 2.0 Protocols

Swift 2.0 Protocols

Achieved
Dec 27, 2015
Achievement
Objects and Optionals

Swift 2.0 Enumerations and Optionals

Achieved
Dec 9, 2015
Achievement
Introduction to Optionals

Swift 2.0 Enumerations and Optionals

Achieved
Dec 7, 2015
Achievement
Introduction to Enumerations

Swift 2.0 Enumerations and Optionals

Achieved
Dec 6, 2015
Achievement
Prepare and Plan

C# Basics (Retired)

Achieved
Nov 19, 2015
Achievement
Running Apps on a Device

Build a Simple iPhone App with Swift 2.0

Achieved
Nov 18, 2015
Achievement
Improving Our User Interface

Build a Simple iPhone App with Swift 2.0

Achieved
Nov 18, 2015
Achievement
Structs as Data Models

Build a Simple iPhone App with Swift 2.0

Achieved
Nov 18, 2015
Achievement
View Controllers and Views

Build a Simple iPhone App with Swift 2.0

Achieved
Nov 18, 2015
Achievement
Getting Started with iOS Development

Build a Simple iPhone App with Swift 2.0

Achieved
Nov 17, 2015
Achievement
Differentiating Between Objects

Object-Oriented Swift 2.0

Achieved
Nov 8, 2015
Achievement
Class Inheritance

Object-Oriented Swift 2.0

Achieved
Nov 8, 2015
Achievement
Classes

Object-Oriented Swift 2.0

Achieved
Nov 8, 2015
Achievement
Complex Data Structures

Object-Oriented Swift 2.0

Achieved
Nov 8, 2015
Achievement
Function Parameters

Swift 2.0 Functions

Achieved
Nov 5, 2015
Achievement
Functions in Swift 2.0

Swift 2.0 Functions

Achieved
Nov 5, 2015
Achievement
Control Flow with Conditional Statements

Swift 2.0 Collections and Control Flow

Achieved
Nov 4, 2015
Achievement
Control Flow With Loops

Swift 2.0 Collections and Control Flow

Achieved
Nov 3, 2015
Achievement
Swift Dictionaries

Swift 2.0 Collections and Control Flow

Achieved
Nov 3, 2015
Achievement
Introduction to Collections

Swift 2.0 Collections and Control Flow

Achieved
Nov 3, 2015
Achievement
Implementing the Detail View

Enhance a Weather App with Table Views

Achieved
Oct 26, 2015
Achievement
Swift Operators

Swift 2.0 Basics

Achieved
Oct 26, 2015
Achievement
Swift Types

Swift 2.0 Basics

Achieved
Oct 20, 2015
Achievement
An Introduction to Swift Programming

Swift 2.0 Basics

Achieved
Oct 18, 2015
Achievement
Introduction to Video Games

How to Make a Video Game

Achieved
Sep 5, 2015
Achievement
Delegation in iOS

Delegates in Swift 2

Achieved
Aug 16, 2015
Achievement
Introduction to Delegates

Delegates in Swift 2

Achieved
Jul 25, 2015
Achievement
Color Theory

Aesthetic Foundations

Achieved
Jul 25, 2015
Achievement
Principles

Aesthetic Foundations

Achieved
Jul 17, 2015
Achievement
Elements

Aesthetic Foundations

Achieved
Jul 16, 2015
Achievement
Custom Table View Cells

Enhance a Weather App with Table Views

Achieved
Jul 7, 2015
Achievement
Next Week's Weather

Enhance a Weather App with Table Views

Achieved
Jul 5, 2015
Achievement
Upgrading Stormy

Enhance a Weather App with Table Views

Achieved
Jul 3, 2015
Achievement
Introduction to Table Views

Enhance a Weather App with Table Views

Achieved
Jun 30, 2015
Achievement
Creating Flexible Objects with Protocols

Swift Protocols

Achieved
Jun 30, 2015
Achievement
Protocols

Swift Protocols

Achieved
Jun 27, 2015
Achievement
What is Agile?

Scrum Basics

Achieved
Jun 23, 2015
Achievement
Refreshing the Data

Build a Weather App with Swift

Achieved
Jun 17, 2015
Achievement
Adding Weather Icons

Build a Weather App with Swift

Achieved
Jun 16, 2015
Achievement
Managing Complexity

Build a Weather App with Swift

Achieved
Jun 15, 2015
Achievement
Interacting With Data From the Web

Build a Weather App with Swift

Achieved
Jun 15, 2015
Achievement
Simple Data Structures

Build a Weather App with Swift

Achieved
Jun 4, 2015
Achievement
Closures in iOS

Swift Closures

Achieved
Jun 1, 2015
Achievement
Closures and Closure Expressions

Swift Closures

Achieved
Jun 1, 2015
Achievement
Functions as First Class Citizens

Swift Closures

Achieved
May 31, 2015
Achievement
Pointers and Memory

Objective-C Basics (Retired)

Achieved
Apr 30, 2015
Achievement
Functional Programming in C

Objective-C Basics (Retired)

Achieved
Apr 27, 2015
Achievement
Cocoapods

iOS Tools

Achieved
Apr 24, 2015
Achievement
The Local Development Environment

Modern WordPress Workflow

Achieved
Apr 22, 2015
Achievement
Getting Started with Android Studio

Android Tools

Achieved
Apr 1, 2015
Achievement
Finishing the User Interface

Build an Interactive Story App (Retired)

Achieved
Mar 30, 2015
Achievement
The Model-View-Controller Pattern

Build an Interactive Story App (Retired)

Achieved
Mar 30, 2015
Achievement
Fundamentals of C

Objective-C Basics (Retired)

Achieved
Mar 30, 2015
Achievement
Intents and Multiple Activities

Build an Interactive Story App (Retired)

Achieved
Mar 28, 2015
Achievement
User Input

Build an Interactive Story App (Retired)

Achieved
Mar 28, 2015
Achievement
Swift Value vs Reference Types

Object-Oriented Swift

Achieved
Mar 26, 2015
Achievement
Swift Properties

Object-Oriented Swift

Achieved
Mar 25, 2015
Achievement
Responsive Patterns

Responsive Layouts

Achieved
Mar 24, 2015
Achievement
Media Queries

Responsive Layouts

Achieved
Mar 24, 2015
Achievement
Responsive Theory

Responsive Layouts

Achieved
Mar 24, 2015
Achievement
Publishing on Google Play

Publish an Android App

Achieved
Mar 9, 2015
Achievement
Testing and Debugging

Build a Simple Android App (2014)

Achieved
Mar 9, 2015
Achievement
Ruby Numbers (Ruby Basics)

Ruby Basics (Retired)

Achieved
Feb 20, 2015
Achievement
Ruby Strings (Ruby Basics)

Ruby Basics (Retired)

Achieved
Feb 19, 2015
Achievement
How Ruby Works

Ruby Basics (Retired)

Achieved
Feb 19, 2015
Achievement
Improving Our Code

Build a Simple Android App (2014)

Achieved
Jan 29, 2015
Achievement
Coding the Fun Facts

Build a Simple Android App (2014)

Achieved
Jan 28, 2015
Achievement
Basic Android Programming

Build a Simple Android App (2014)

Achieved
Jan 28, 2015
Achievement
Self-Assessment

Careers Foundations

Achieved
Jan 25, 2015
Achievement
Getting Started with CSS

CSS Foundations

Achieved
Jan 20, 2015
Achievement
Table Basics

HTML Tables

Achieved
Jan 20, 2015
Achievement
Refactoring Our Code (Swift)

Build a Playlist Browser with Swift

Achieved
Jan 17, 2015
Achievement
Building the Master and Detail Views (Swift)

Build a Playlist Browser with Swift

Achieved
Jan 17, 2015
Achievement
Building a Music Library and Playlists (Swift)

Build a Playlist Browser with Swift

Achieved
Jan 17, 2015
Achievement
Using a Navigation Controller With Segues (Swift)

Build a Playlist Browser with Swift

Achieved
Jan 16, 2015
Achievement
Working With Multiple View Controllers (Swift)

Build a Playlist Browser with Swift

Achieved
Jan 16, 2015
Achievement
Swift Inheritance

Object-Oriented Swift

Achieved
Jan 16, 2015
Achievement
Swift Classes and Objects

Object-Oriented Swift

Achieved
Jan 15, 2015
Achievement
AngularJS MVC Frameworks

AngularJS

Achieved
Dec 19, 2014
Achievement
Building a Command Line Application

Node.js Basics (2014)

Achieved
Dec 19, 2014
Achievement
Introduction to Node.js

Node.js Basics (2014)

Achieved
Dec 19, 2014
Achievement
Choosing Options

HTML Forms

Achieved
Dec 18, 2014
Achievement
Organizing Forms

HTML Forms

Achieved
Dec 18, 2014
Achievement
Form Basics

HTML Forms

Achieved
Dec 18, 2014
Achievement
Creating the Initial Screen Layout

Build a Simple Android App (2014)

Achieved
Dec 15, 2014
Achievement
Getting Started with Android

Build a Simple Android App (2014)

Achieved
Dec 15, 2014
Achievement
Downloading Data with NSURLSession

Build a Photo Browser iPhone App

Achieved
Nov 10, 2014
Achievement
Collection Views

Build a Photo Browser iPhone App

Achieved
Nov 10, 2014
Achievement
WordPress Themes

How to Make a Website with WordPress

Achieved
Nov 9, 2014
Achievement
Installing Wordpress

How to Make a Website with WordPress

Achieved
Nov 9, 2014
Achievement
Swift Structs and their Methods

Swift Enums and Structs

Achieved
Nov 8, 2014
Achievement
Swift Enums and their Methods

Swift Enums and Structs

Achieved
Nov 8, 2014
Achievement
Swift Enums

Swift Enums and Structs

Achieved
Nov 7, 2014
Achievement
Swift Structs

Swift Enums and Structs

Achieved
Nov 7, 2014
Achievement
An Overview of WordPress Frameworks

Genesis Framework Foundations

Achieved
Nov 6, 2014
Achievement
Working with CSS and JS in WordPress Themes

WordPress Theme Development

Achieved
Oct 25, 2014
Achievement
Starting a WordPress Theme

WordPress Theme Development

Achieved
Oct 25, 2014
Achievement
Displaying Our Weather Data

Build a Weather App with Swift (Retired)

Achieved
Oct 5, 2014
Achievement
Data Modeling With Structures

Build a Weather App with Swift (Retired)

Achieved
Oct 5, 2014
Achievement
Concurrency

Build a Weather App with Swift (Retired)

Achieved
Oct 5, 2014
Achievement
Pulling Data From the Web

Build a Weather App with Swift (Retired)

Achieved
Oct 5, 2014
Achievement
Deploying to a Device

Build a Simple iPhone App with Swift

Achieved
Sep 29, 2014
Achievement
Debugging Our App

Build a Simple iPhone App with Swift

Achieved
Sep 29, 2014
Achievement
Improving Our User Interface

Build a Simple iPhone App with Swift

Achieved
Sep 29, 2014
Achievement
Using a Data Model

Build a Simple iPhone App with Swift

Achieved
Sep 29, 2014
Achievement
Views and View Controllers

Build a Simple iPhone App with Swift

Achieved
Sep 28, 2014
Achievement
Getting Started with Xcode

Build a Simple iPhone App with Swift

Achieved
Sep 28, 2014
Achievement
Swift Optionals

Swift Functions and Optionals

Achieved
Sep 28, 2014
Achievement
Swift Parameters and Tuples

Swift Functions and Optionals

Achieved
Sep 27, 2014
Achievement
Swift Functions

Swift Functions and Optionals

Achieved
Sep 27, 2014
Achievement
Control Flow

Swift Basics (retired)

Achieved
Sep 21, 2014
Achievement
Collections

Swift Basics (retired)

Achieved
Sep 21, 2014
Achievement
Operators

Swift Basics (retired)

Achieved
Sep 21, 2014
Achievement
Types

Swift Basics (retired)

Achieved
Sep 20, 2014
Achievement
Variables and Constants

Swift Basics (retired)

Achieved
Sep 20, 2014
Achievement
Retrieving and Viewing Data from Parse.com

Build a Self-Destructing Message iPhone App

Achieved
Aug 15, 2014
Achievement
Capturing Photo and Video Using UIImagePickerController

Build a Self-Destructing Message iPhone App

Achieved
Aug 14, 2014
Achievement
Relating Users in Parse.com

Build a Self-Destructing Message iPhone App

Achieved
Aug 12, 2014
Achievement
Using Parse.com as a Backend and Adding Users

Build a Self-Destructing Message iPhone App

Achieved
Aug 9, 2014
Achievement
Designing and Starting the App

Build a Self-Destructing Message iPhone App

Achieved
Aug 9, 2014
Achievement
Particle Systems and Keeping Score

Build a Game with Sprite Kit

Achieved
Aug 6, 2014
Achievement
Artificial Intelligence and Sound

Build a Game with Sprite Kit

Achieved
Aug 2, 2014
Achievement
Physics and Collision

Build a Game with Sprite Kit

Achieved
Jul 27, 2014
Achievement
Actions and Animations

Build a Game with Sprite Kit

Achieved
Jul 9, 2014
Achievement
Game Loop and Texture Atlas

Build a Game with Sprite Kit

Achieved
Jul 7, 2014
Achievement
Intro to Sprite Kit

Build a Game with Sprite Kit

Achieved
Jul 7, 2014
Achievement
Introduction to Game Design

Mobile Game Design

Achieved
Jun 26, 2014
Achievement
Create Bootstrap Styled Theme Templates

From Bootstrap to WordPress

Achieved
May 21, 2014
Achievement
Setup a Bootstrap Theme

From Bootstrap to WordPress

Achieved
May 16, 2014
Achievement
Local WordPress Development

Local WordPress Development

Achieved
May 13, 2014
Achievement
Custom Detail View Controller

Build a Diary App Using Core Data

Achieved
May 12, 2014
Achievement
Custom UITableViewCell

Build a Diary App Using Core Data

Achieved
May 12, 2014
Achievement
Deleting Data

Build a Diary App Using Core Data

Achieved
May 11, 2014
Achievement
Listing Data using NSFetchedResultsController

Build a Diary App Using Core Data

Achieved
May 11, 2014
Achievement
Inserting and Saving Data

Build a Diary App Using Core Data

Achieved
May 10, 2014
Achievement
Understanding Core Data

Build a Diary App Using Core Data

Achieved
May 9, 2014
Achievement
Moving Forward with UX

UX Basics

Achieved
May 9, 2014
Achievement
Tools UXers Use

UX Basics

Achieved
May 9, 2014
Achievement
How UXers Think

UX Basics

Achieved
May 8, 2014
Achievement
What Do User Experience Designers Do?

UX Basics

Achieved
May 8, 2014
Achievement
What is User Experience (UX)?

UX Basics

Achieved
May 8, 2014
Achievement
Introduction

HTML

Achieved
Apr 25, 2014
Achievement
Debugging HTML and CSS Problems

How to Make a Website

Achieved
Apr 25, 2014
Achievement
Sharing a Website

How to Make a Website

Achieved
Apr 10, 2014
Achievement
Responsive Web Design and Testing

How to Make a Website

Achieved
Apr 10, 2014
Achievement
Adding Pages to a Website

How to Make a Website

Achieved
Apr 10, 2014
Achievement
Styling Web Pages and Navigation

How to Make a Website

Achieved
Apr 9, 2014
Achievement
Customizing Colors and Fonts

How to Make a Website

Achieved
Apr 9, 2014
Achievement
CSS: Cascading Style Sheets

How to Make a Website

Achieved
Apr 9, 2014
Achievement
Creating HTML Content

How to Make a Website

Achieved
Apr 9, 2014
Achievement
HTML First

How to Make a Website

Achieved
Apr 9, 2014
Achievement
Beginning HTML and CSS

How to Make a Website

Achieved
Apr 9, 2014
Achievement
Newbie

Achieved
Apr 9, 2014