Holger Liesegang

Holger Liesegang

Germany / Siegen

Web & iOS developer, stays current at Treehouse

50,595

Total Points

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Skills & Experience

  • Spoken Languages

    • English
    • German
    • French (basic)

622 Achievements

  • Getting Started with Xamarin
  • Structs as Data Models
  • View Controllers and Views
  • Getting Started with iOS Development
  • Differentiating Between Objects
  • Class Inheritance
  • Classes
  • Complex Data Structures
  • Function Parameters
  • Functions in Swift 2.0
  • Control Flow with Conditional Statements
  • Control Flow With Loops
  • Swift Dictionaries
  • Introduction to Collections
  • Save for the Web
  • Adding Images and a Mockup
  • Swift Operators
  • Logo Design
  • Swift Types
  • Creating a Wireframe
  • Introducing Adobe Illustrator
  • An Introduction to Swift Programming
  • Delegation in iOS
  • Introduction to Delegates
  • How to Install WordPress on Your Computer
  • Simple Mobile Interface
  • Exporting Designs
  • Sketch Features
  • Introducing Sketch
  • MASH JavaScript
  • MASH CSS
  • MASH HTML
  • The Internet
  • Refactoring Our Code (objc)
  • Building the Master and Detail Views (objC)
  • Managing Playlist Data (objC)
  • Building a Music Library Model (objc)
  • Working With Multiple View Controllers (ObjC)
  • Refreshing the Data
  • Adding Weather Icons
  • Managing Complexity
  • Interacting With Data From the Web
  • Simple Data Structures
  • Deploying to a Device (ObjC)
  • Debugging Our App (ObjC)
  • Improving Our User Interface (ObjC)
  • Creating a Data Model (ObjC)
  • Views and View Controllers (ObjC)
  • Getting Started with Xcode (ObjC)
  • Implementing the Detail View
  • Custom Table View Cells
  • Next Week's Weather
  • Upgrading Stormy
  • Introduction to Table Views
  • Creating Flexible Objects with Protocols
  • Protocols
  • Adding Push Notifications from Parse.com
  • Updating Other GridViews
  • Customizing a GridView for Friends
  • Customizing a ListView for the Inbox
  • Customizing the Action Bar
  • Using Custom Styles and Themes
  • Responsive Patterns
  • Media Queries
  • Closures in iOS
  • Closures and Closure Expressions
  • Functions as First Class Citizens
  • Item Completion & Interaction
  • Nested Edits & Updates
  • Responsive Theory
  • Art Direction with the Picture Element
  • Image Delivery with Srcset and Sizes
  • Nested Routes & Controllers
  • Relating Models
  • Laravel CRUD
  • Validation & Flash Messages
  • Laravel Forms
  • WWW
  • Laravel & Databases
  • Laravel Controllers
  • Customizing the Login Screen
  • Computer Languages
  • Computer Basics
  • PHP Internal Functions
  • PHP Returns & Closures
  • Laravel Project Setup
  • PHP Functions Basics
  • Starting with Design Mockups
  • Refactoring Our Code (Swift)
  • Building the Master and Detail Views (Swift)
  • Laravel Getting Started
  • Building a Music Library and Playlists (Swift)
  • Using a Navigation Controller With Segues (Swift)
  • Working With Multiple View Controllers (Swift)
  • Swift Value vs Reference Types
  • Swift Properties
  • Swift Inheritance
  • Swift Classes and Objects
  • Finishing the User Interface
  • The Model-View-Controller Pattern
  • Intents and Multiple Activities
  • User Input
  • Publishing on Google Play
  • Testing and Debugging
  • Improving Our Code
  • Coding the Fun Facts
  • Basic Android Programming
  • Custom Media Players
  • Captioning Video
  • Media Basics
  • JavaScript Functions
  • JavaScript Conditional Statements
  • JavaScript Numbers
  • Creating the Initial Screen Layout
  • Creating an SVG
  • Introduction to SVG
  • Getting Started with Android
  • Making sense of it all
  •  Learning activity: Interviewing
  • Learning activity: Field Observation
  • Learning activity: Experience Sampling
  • Displaying Our Weather Data
  • Data Modeling With Structures
  • Finding participants for your learning activity
  • Solving an Important Problem
  • Concurrency
  • Pulling Data From the Web
  • JavaScript Variables
  • Introducing JavaScript
  • Dungeon Game
  • Tuples
  • Dictionaries
  • Slices
  • Perfecting the Prototype
  • Using your New Tools
  • Getting Started with Java
  • Treehouse Club - CSS
  • PHP Loops
  • Deploying to a Device
  • Debugging Our App
  • Improving Our User Interface
  • PHP Conditionals
  • PHP Datatypes
  • PHP Data & Structure
  • Moving from WordPress.com to Self-Hosted WordPress.org
  • Lists Redux
  • Using a Data Model
  • Particle Systems and Keeping Score
  • Artificial Intelligence and Sound
  • Physics and Collision
  • Actions and Animations
  • Game Loop and Texture Atlas
  • Intro to Sprite Kit
  • Ruby Methods
  • Ruby Numbers (Ruby Basics)
  • Ruby Strings (Ruby Basics)
  • How Ruby Works
  • Views and View Controllers
  • Swift Structs and their Methods
  • Swift Structs
  • Swift Enums and their Methods
  • Swift Enums
  • Structuring Tables
  • Getting Started with Xcode
  • Swift Optionals
  • Swift Parameters and Tuples
  • Ruby Logical Operators
  • Ruby Control Structures
  • Swift Functions
  • Ruby Operators
  • Control Flow
  • Collections
  • Operators
  • Types
  • Variables and Constants
  • Getting Started with WordPress
  • Self-Destruction
  • Retrieving and Viewing Messages
  • Sending Messages
  • Capturing Photos and Videos
  • Relating Users in Parse.com
  • Treehouse Club - JavaScript
  • Next Steps
  • Financing Our Company
  • Selling Your Product
  • Table Basics
  • Marketing Your Product
  • Product Market Fit
  • Discovery
  • PHP Getting Started
  • Welcome to the Treehouse Club
  • Using Fragments for Tabs
  • Adding Users Using Parse.com
  • Custom Dashboard Widgets
  • Controlling Admin Navigation
  • Customizing the Login Screen
  • Admin Color Schemes
  • Pick a Number! Any Number!
  • Putting the "Fun" Back in "Functions"
  • Shopping List
  • Things That Count
  • Ins & Outs
  • Say Hello to Python
  • Cleanup and Feature Merge
  • Maintaining The Test Suite
  • Polishing Rails Applications
  • Static Pages with Rails
  • Finalizing the Project
  • Case Studies and Examples
  • The Brand Identity Design Process
  • Creating an App Tutorial
  • Blank Slates and Rails
  • Email with Rails
  • Choosing Options
  • Organizing Forms
  • Form Basics
  • Introduction to Brand Identity
  • Starting the App
  • Finding Good WordPress Plugins and Themes
  • Managing Comments on a WordPress Blog
  • Working with Media in WordPress Blogs
  • Posts and Pages in WordPress
  • Blogging with WordPress Overview
  • Styling Rails Models
  • Ruby on Rails Helpers
  • Rails Partials
  • Modifying Todo Lists
  • Form Builders and Rails
  • Styling Rails Forms
  • Using Intents to Display and Share Posts
  • Adapting Data for Display in a List
  • Styling a Header
  • Sass and Rails
  • Working with Rails Layouts
  • Zurb Foundation on Rails
  • Remember Me
  • Soft Skills - Psychology
  • WordPress User Roles
  • Testing and Sharing the Extension
  • Building the Extension
  • Start menu and App Icon
  • Sound Design
  • Animating and Saving Sprites
  • Designing Characters and a Scene
  • Introduction to Game Design
  • Writing Online
  • AR Extensions
  • Callbacks
  • Query Interface
  • Validation
  • Migrations and Relationships
  • Introduction to ActiveRecord
  • Getting Data from the Web
  • Rebuilding from Scratch
  • Exploring the Master-Detail Template
  • Add Bootstrap Components to WordPress Theme
  • Create Bootstrap Styled Theme Templates
  • Setup a Bootstrap Theme
  • Spriting with Compass
  • Compass Helper Functions
  • Compass Layout and Typography
  • Getting Started with Compass
  • Custom Detail View Controller
  • Custom UITableViewCell
  • Deleting Data
  • Listing Data using NSFetchedResultsController
  • Inserting and Saving Data
  • Understanding Core Data
  • Creating a Simple Drawing Application
  • Creating a Password Confirmation Form
  • Creating a Mobile Drop Down Menu
  • Creating a Simple Lightbox
  • Animate This (iOS7)
  • Creating a Spoiler Revealer
  • Introduction to jQuery
  • Productivity
  • Sharing Your Creation
  • Interrogating the App
  • Shaking Things Up
  • Pretty Little Things
  • Learning the Language
  • Getting Started with Android
  • Password Resets and Testing
  • Adding User Support to Our Application
  • Password Hashing and Sign-In
  • Build a Todo List Application with Rails 4
  • Moving Forward with UX
  • Tools UXers Use
  • How UXers Think
  • What Do User Experience Designers Do?
  • What is User Experience (UX)?
  • The WordPress Codex
  • Push Updates
  • Activity Feeds
  • Create an Image Gallery
  • Uploading and Resizing Images
  • Uploading Files
  • Managing Friendships
  • Using AJAX
  • Adding State
  • Building the Friendship UI
  • Creating Friendships
  • Ruby Testing
  • Standard Library
  • Ruby Core
  • Ruby Modules
  • Ruby Procs & Lambdas
  • Ruby Blocks
  • Ruby Loops
  • Ruby Methods
  • Ruby Hashes
  • Ruby Arrays
  • Ruby Numbers
  • Ruby Strings
  • Objects, Classes, and Variables
  • WordPress Admin Settings
  • Better SEO Through Tools
  • UIKit Dynamics
  • View Controller Transitions
  • Better SEO Through Code
  • Gestures
  • Better SEO Through Content
  • Introduction to SEO
  • What is an API?
  • Downloading Data with NSURLSession
  • Collection Views
  • Cocoapods
  • Rails Deployment
  • Building the Profile Page
  • Testing the Whole App
  • Rails Routing
  • Business Plan for Freelance Business
  • Writing Tests
  • Ruby Basics
  • Customizing Ruby on Rails Forms
  • Ruby on Rails Authentication
  • Rails Frontend Development
  • Getting Started With Rails
  • Installing a Ruby Development Environment
  • Customizing BuddyPress
  • Social Interactions in BuddyPress
  • Manage BuddyPress Member Profiles
  • Getting Started with BuddyPress
  • PHP Inheritance & Interfaces
  • PHP Properties & Methods
  • PHP Objects and Classes
  • Grid Layout
  • Flexbox Layout
  • Positioning Schemes
  • Float Layout
  • Display Modes
  • Launching and Supporting a WordPress Plugin
  • Building WordPress Template Tags, Widgets, and Shortcodes
  • Connecting WordPress Plugins with 3rd Party APIs
  • Building a WordPress Plugin Settings Page
  • How WordPress Plugins Work
  • Debugging HTML and CSS Problems
  • Sharing a Website
  • Responsive Web Design and Testing
  • Adding Pages to a Website
  • Styling Web Pages and Navigation
  • Customizing Colors and Fonts
  • CSS: Cascading Style Sheets
  • Creating HTML Content
  • HTML First
  • Beginning HTML and CSS
  • Presentation Skills
  • WordPress.com Social Features
  • Building a WordPress.com Site
  • Getting Started with WordPress.com
  • Local WordPress Development
  • Advanced Sass Concepts
  • WordPress Plugin Best Practices
  • Widgets and Custom Menus
  • Custom Post Types and Fields
  • Customizing WordPress Themes
  • WordPress Themes
  • Installing Wordpress
  • Speeding up Workflow With Sass
  • Using Git for Android
  • Getting Started with Genymotion
  • Getting Started with Android Studio
  • Variables, Mixins, and Extending Selectors
  • Getting Started with Sass
  • Launching a WordPress Site
  • WordPress and Forms
  • Extending WordPress Template Functionality
  • Converting Static HTML into WordPress Templates
  • Creating Home Page Assets
  • Applying Effects
  • Preparing to Code WordPress Templates
  • Business Plan Basics
  • WordPress Theme Functions
  • Working with a Developer
  • Designing our App
  • Wireframing, Interaction Design and Planning
  • ADS Writing and Preparation
  • Introduction to UI Design
  • WordPress Theme Templates
  • Content Strategy with WordPress
  • What's New in Foundation 5
  • Workflows
  • Working With Remote Repositories
  • Merging
  • Branches
  • Getting Started With Git
  • Why Version Control Matters
  • Finishing the User Interface
  • Customizing Table View Controllers
  • Using Auto Layout and Managing the Keyboard
  • Implementing Custom Login and Sign Up Screens
  • Important Skills For Professional Success
  • Retrieving and Viewing Data from Parse.com
  • Capturing Photo and Video Using UIImagePickerController
  • Chrome DevTools Basics
  • Relating Users in Parse.com
  • Using Parse.com as a Backend and Adding Users
  • Designing and Starting the App
  • Viewing a Web Page
  • Adapting Data for Display
  • Data Modeling
  • Getting Data from the Web
  • Rebuilding from Scratch
  • Exploring the Master-Detail Template
  • Owning a WordPress Site Long Term
  • WordPress Community Management
  • Working with Media in WordPress
  • Adding and Editing Content
  • Getting a WordPress Site
  • Customizing WordPress
  • Managing Comments
  • Adding and Editing Content in WordPress
  • Configuring WordPress
  • Getting Started with WordPress
  • Going Mobile
  • Designing Email with CSS
  • Coding HTML Email
  • Beyond the Basics
  • Installing Programs
  • Environment and Redirection
  • Console Processes
  • Console Users and Permission
  • Limiting Results in Queries
  • Using Relationship Tables
  • Filtering Input for Queries
  • Querying the Database
  • Connecting to MySQL
  • Build a Website With Foundation
  • Prototyping With Foundation
  • Securing and Maintaining a MySQL Database
  • SQL Calculating, Aggregating and Other Functions
  • Joining Relational Data Between Tables in SQL
  • Manipulating Schema with SQL
  • Creating Tables and Manipulating Data with SQL
  • Reading Data from Databases with SQL
  • Installing MySQL Server and MySQL Workbench
  • Introduction to Data, Databases and SQL
  • Build a Website With Bootstrap
  • Prototyping With Bootstrap
  • Introduction to Front-End Frameworks
  • Paginating a List: Model and View
  • Paginating a List: Controller
  • Adding Search: Model
  • Adding Search: Controller & View
  • Refactoring the Codebase
  • Cleaning URLs with Rewrite Rules
  • Cleaning URLs with Subfolders
  • Integrating Validation Errors
  • Simple PHP Application: Wrapping Up The Project
  • Working with PHP Functions
  • HTML Email Basics
  • Integrating With Paypal
  • Listing Inventory Items
  • The Logo Sprint
  • Logo Design 101
  • Adding a Contact Form
  • Metrics
  • Protecting and Sharing Your Work
  • Licensing
  • Fair Use and Public Domain
  • Getting Started with Copyright
  • Improving Usability
  • Mobile Usability
  • Website Usability
  • What is Usability?
  • Design Foundations Final
  • Becoming a Problem Solver
  • Understanding Aesthetics
  • Getting Work Done
  • A Lifestyle Choice
  • Growing Your Business
  • Client Services
  • Sales and Pitching
  • Professional Development
  • Applying & Interviewing
  • The Job Search
  • Networking
  • Personal Branding
  • Setting Your Course
  • Careers in the Tech Industry
  • Self-Assessment
  • Creating a Long Term Business
  • Protecting Yourself With Contracts
  • Establishing a Proper Workflow
  • Pricing and Project Proposals
  • Finding Your First Project
  • Starting a Freelance Career
  • API Access
  • Location
  • Blocks and Categories
  • App Settings
  • Appearance
  • Notifications
  • iOS 5 Core Data
  • Advanced Objective-C
  • Foundation Framework
  • Introduction to Design
  • Introduction to Objective-C
  • Pointers and Memory
  • Functional Programming in C
  • Fundamentals of C
  • Marketing and Promotion
  • Moving Beyond the Blog
  • Finding Business
  • Creating Content
  • Introduction to Blogging
  • Web View
  • Sales
  • Web Apps
  • Websites
  • Introduction
  • Creating the Menu and Footer
  • Customizing Google Maps
  • Google Maps Integration
  • jQuery Plugins
  • Form Validation and Manipulation
  • Pricing
  • Moving Around in the Console
  • DNS Basics
  • Introduction to jQuery
  • Financing Your Company
  • JavaScript Objects
  • From Idea to Execution
  • JavaScript Functions
  • JavaScript Arrays
  • Graphic Basics
  • Making Money
  • JavaScript Numbers
  • Marketing Strategy
  • Introduction to Accounting
  • Marketing Basics
  • Forming Your Company
  • JavaScript Strings
  • Corporate Structure
  • Why Start a Business?
  • Search Engine Optimization
  • Introduction Variables
  • How to Draw in Illustrator
  • Advanced Techniques
  • Responsive Design
  • Website Basics
  •  Adding Color and Type
  • Adaptive Design
  • Fluid Foundation
  • Introduction to Responsive Web Design
  • Storyboards
  • Creating an Icon
  • Introduction to Illustrator
  • Usability Testing
  • Usability Basics
  • Media Queries
  • CSS Animations
  • Transitions and Transforms
  • Workflow Basics
  • Slices & Save for Web
  • Vector Shapes
  • Type Tools
  • Masks Basics
  • Layer Basics
  • Workspace Basics
  • Flexbox and Multi-Column Layout
  • Social Media
  • Gradients
  • Web Typography
  • Backgrounds and Borders
  • Testing and Debugging
  • Getting Started with PHP
  • Video Marketing
  • Animate This
  • Automatic Reference Counting
  • CSS Box Model
  • Designing your App
  • Color Theory
  • Principles
  • Elements
  • Refactoring into a Model
  • Creating a Data Collection
  • Understanding Views and View Controllers
  • Getting Started (iOS7)
  • Functions
  • Objects and Arrays
  • Control Structures
  • Basics
  • Text, Fonts, and Lists
  • Email Marketing
  • Values and Units
  • Advanced Selectors
  • Selectors
  • Getting Started with CSS
  • Forms
  • Tables
  • Objects
  • Links
  • Lists
  • Text
  • Introduction
  • Launching the Website
  • Styling Content
  • Creating a Website Structure
  • Text Editors and HTML
  • Website Basics
  • Newbie