book

.NET Domain-Driven Design with C#: Problem – Design – Solution

Name: .NET Domain-Driven Design with C#: Problem – Design – Solution
Author: Tim McCarthy
ISBN: 9780470147566

by Tim McCarthy

April 2008

Intermediate to advanced

430 pages

10h

English

Wrox

Read now

Unlock full access

Copyright
About the Author
Credits
Acknowledgments
Introduction
Who This Book Is ForWhat This Book CoversHow This Book Is StructuredWhat You Need to Use This BookSource CodeErratap2p.wrox.com
1. Introducing the Project: The SmartCA Application
1.1. The Problem1.2. The Design1.2.1. Reliability and Availability1.2.2. Scalability1.2.3. Maintainability1.2.4. Rich Client Application Functionality1.2.5. Offline Capable1.2.6. Web Access1.2.7. Intelligent Installation and Auto-Update Functionality1.2.8. Additional Client Device Support1.3. The Solution1.3.1. Fulfilling the Reliability, Availability, Scalability, Offline Capable, and Additional Client Device Support Requirements1.3.1.1. On the Server1.3.1.2. On the Client1.3.2. Fulfilling the Maintainability Requirement1.3.3. Fulfilling the Rich Client Application Functionality Requirement1.3.3.1. Windows Application Benefits1.3.3.2. Web Application Benefits1.3.3.3. Smart Client Definition1.3.3.4. Windows Presentation Foundation (WPF)1.3.4. Fulfilling the Web Access Requirement1.3.5. Fulfilling the Intelligent Installation and Auto-Update Functionality Requirement1.4. Summary
2. Designing the Layered Architecture
2.1. The Problem2.2. The Design2.2.1. Designing the Visual Studio Solution2.2.2. Designing the Architectural Layers2.2.2.1. Designing the Application Layer2.2.2.2. Designing the Domain Layer2.2.2.2.1. Important Domain-Driven Design Concepts2.2.2.2.2. Entities2.2.2.2.3. Value Objects2.2.2.2.4. Services2.2.2.2.5. Application Layer Services2.2.2.2.6. Domain Layer Services2.2.2.2.7. Infrastructure Layer Services2.2.2.2.8. Aggregates2.2.2.2.9. Repositories2.2.2.2.10. Factories2.2.2.2.11. Using Repositories in the Domain Layer2.2.2.2.12. Using the Layered Supertype Pattern2.2.2.3. Designing the Infrastructure Layer2.2.2.4. Designing the Presentation Layer2.3. The Solution2.3.1. Implementing the Visual Studio Solution2.3.2. Implementing the Architectural Layers2.3.2.1. Layered Supertype2.3.2.2. Repository Framework2.3.2.2.1. The Interfaces2.3.2.2.2. The Repository Factory2.3.2.2.3. Configuration Section2.3.2.2.4. Configuration Section Handling2.3.2.2.5. The RepositoryFactory Class2.3.2.2.6. Unit of Work2.3.2.2.7. The Repository Base Classes2.3.2.2.8. The RepositoryBase<T> Class2.3.2.2.9. The SqlCeRepositoryBase<T> Class2.3.2.2.10. The Entity Factory Framework2.3.2.2.11. The IEntityFactory<T> Interface2.3.2.2.12. Configuration Section2.3.2.2.13. Configuration Section Handling2.3.2.2.14. The EntityFactoryBuilder Class2.3.2.3. The Model-View-ViewModel Pattern2.3.2.3.1. Traditional Presentation Patterns2.3.2.3.2. Model-View-ViewModel Definition2.3.2.3.3. What's a ViewModel?2.3.2.3.4. An Example2.4. Summary
3. Managing Projects
3.1. The Problem3.2. The Design3.2.1. Designing the Domain Model3.2.2. Defining the Project Aggregate3.2.3. Defining the Aggregate Boundaries3.2.4. Designing the Repositories3.2.4.1. The IProjectRepository Interface3.2.4.2. The IEmployeeRepository Interface3.2.5. Writing the Unit Tests3.2.5.1. Setting Up the Unit Tests Project3.2.5.2. The IProjectRepository Unit Tests3.2.5.3. The FindBySegmentsAndNotCompletedTest Method3.2.5.4. The FindByProjectNumberTest Method3.2.5.5. The FindAllMarketSegmentsTest Method3.2.6. The IEmployeeRepository Unit Tests3.2.6.1. The GetPrincipalsTest Method3.2.6.2. The GetConstructionAdministratorsTest Method3.3. The Solution3.3.1. The Project Class3.3.1.1. The Private Fields and Constructors3.3.2. The Properties3.3.2.1. The Name and Number Properties3.3.2.2. The Address Property3.3.2.3. The Owner Property3.3.2.4. The ConstructionAdministrator and PrincipalInCharge Properties3.3.2.5. The Segment Property3.3.2.6. The ContingencyAllowanceAmount, TestingAllowanceAmount, and UtilityAllowanceAmount Properties3.3.2.7. The Contracts Property3.3.3. The Repository Implementations3.3.3.1. The Project Repository3.3.3.2. Refactoring the FindAll and FindBy Methods3.3.3.3. The Organization of the ProjectRepository Class3.3.3.4. The Constructors3.3.3.5. The IProjectRepository Implementation3.3.3.6. The BuildChildCallbacks Method3.3.3.7. The AppendOwner Callback Method3.3.3.8. The AppendConstructionAdministrator and AppendPrincipal Callback Methods3.3.3.9. The AppendProjectAllowances Callback Method3.3.3.10. The GetBaseQuery Method3.3.3.11. The GetBaseWhereClause Method3.3.3.12. The Unit of Work Implementation3.3.4. The Employee Repository3.3.4.1. The Constructors3.3.5. The IEmployeeRepository Implementation3.3.5.1. The GetBaseQuery Method3.3.5.2. The GetBaseWhereClause Method3.3.6. The Service Class Implementations3.3.6.1. The ProjectService Class3.3.7. The EmployeeService Class3.3.8. The Project Information ViewModel Implementation3.3.8.1. The ViewModel Class Revisited3.3.8.2. The ProjectInformationViewModel Class3.3.8.3. The Constructors3.3.8.4. The MutableAddress Class3.3.8.5. Using the C# 3.0 Initializer Features3.3.8.6. Transforming the Model Objects into View Objects3.3.8.7. The Properties3.4.1. The Project Information View Implementation3.4. Summary
4. Companies and Contacts
4.1. The Problem4.2. The Design4.2.1. Designing the Domain Model4.2.2. Defining the Company and Contact Aggregates4.2.3. Defining the Aggregate Boundaries4.2.4. Designing the Repositories4.2.4.1. The ICompanyRepository Interface4.2.4.2. The IContactRepository Interface4.2.4.3. The IProjectRepository Interface Revisited4.2.5. Writing the Unit Tests4.2.5.1. The ICompanyRepository Unit Tests4.2.5.1.1. The FindByKeyTest Method4.2.5.1.2. The FindAllTest Method4.2.5.1.3. The AddTest Method4.2.5.1.4. The UpdateTest Method4.2.5.1.5. The RemoveTest Method4.2.5.2. The IContactRepository Unit Tests4.2.5.3. The IProjectRepository Unit Test4.3. The Solution4.3.1. The Company Class4.3.2. The Contact Class4.3.3. The ProjectContact Class4.3.4. The Repository Implementations4.3.4.1. The Company Repository4.3.4.1.1. Public Constructors4.3.4.1.2. BuildChildCallbacks4.3.4.1.3. The AppendAddresses Callback4.3.4.1.4. GetBaseQuery4.3.4.1.5. GetBaseWhereClause4.3.4.1.6. Unit of Work Implementation4.3.4.2. The Contact Repository4.3.4.2.1. Public Constructors4.3.4.2.2. GetBaseQuery4.3.4.2.3. GetBaseWhereClause4.3.4.2.4. Unit of Work Implementation4.3.5. The Refactored Project Repository Implementation4.3.6. The Service Class Implementations4.3.6.1. The CompanyService Class4.3.6.2. The ContactService Class4.3.6.3. The ProjectService Class4.3.7. The Company ViewModel4.3.7.1. Constructor4.3.7.2. Properties4.3.7.3. Command Handler Methods4.3.8. The Company View4.3.8.1. Using the Xceed Data Grid4.3.8.2. The Headquarters Address Addresses Dropdown4.3.9. The Project Contact View Model4.3.9.1. Constructor4.3.9.2. Properties4.3.9.3. Command Handler Methods4.3.9.4. The Project Contact View4.4. Summary
5. Submittal Transmittals
5.1. The Problem5.2. The Design5.2.1. Designing the Domain Model5.2.2. Defining the Submittal Aggregate5.2.3. Defining the Aggregate Boundaries5.2.4. Designing the Repository5.2.5. Writing the Unit Tests5.2.5.1.5.2.5.1.1. The FindSubmittalsByProjectTest Method5.2.5.1.2. The AddSubmittalTest Method5.2.5.1.3. The UpdateSubmittalTest Method5.2.5.1.4. The RemoveSubmittalTest Method5.3. The Solution5.3.1.5.3.1.1. Implementing the Submittal Class Private Fields and Constructors5.3.1.2. The Submittal Properties5.3.1.2.1. The SpecSection Property5.3.1.2.2. The DeliveryMethod Property5.3.1.2.3. The CopyToList Property5.3.1.2.4. The TrackingItems Property5.3.1.2.5. The Constructor5.3.1.2.6. The TotalItemsSent and TotalItemsReceived Properties5.3.1.2.7. The DeferredApproval Property5.3.1.2.8. The Status Property5.3.1.2.9. The RoutingItems Property5.3.1.2.10. The Constructor5.3.1.2.11. The Properties5.3.1.2.12. The Status Property5.3.1.2.13. The RemainderLocation Property5.3.2. The Submittal Repository Implementation5.3.2.1.5.3.2.1.1. The AppendFrom Callback5.3.2.1.2. The AppendTo Callback5.3.2.1.3. The AppendCopyToList Callback5.3.2.1.4. The AppendTrackingItems Callback5.3.2.1.5. The AppendRoutingItems Callback5.3.2.1.6. Unit of Work Implementation5.3.2.1.7. The PersistNewItem Method5.3.2.1.8. The PersistUpdatedItem Method5.3.2.1.9. The PersistDeletedItem Method5.3.3. The Submittal Service Implementation5.3.4. The Submittal View Model5.3.4.1. The Constructor5.3.4.2. The Properties5.3.4.3. Command Handler Methods5.3.5. The Submittal View5.3.5.1. Using the StackPanel Element5.3.5.2. Using the Xceed DatePicker Control5.3.5.3. The CopyToList Section5.4. Summary

6. Requests for Information
6.1. The Problem6.2. The Design6.2.1. Designing the Domain Model6.2.2. Defining the RFI Aggregate6.2.3. Defining the Aggregate Boundaries6.2.4. Designing the Repositoryx6.2.5. Writing the Unit Tests6.2.5.1.6.2.5.1.1. The FindRfisByProjectTest Method6.2.5.1.2. The AddRfiTest Method6.2.5.1.3. The UpdateRfiTest Method6.2.5.1.4. The RemoveRfiTest Method6.3. The Solution6.3.1.6.3.1.1. The RFI Class Private Fields and Constructors6.3.1.2. The RFI Properties6.3.1.2.1. The DaysLapsed Property6.3.1.2.2. The NumberSpecification Property6.3.1.2.3. The DateToFieldSpecification Property6.3.1.2.4. The QuestionAnswerSpecification Property6.3.2. The RFI Repository Implementation6.3.2.1. The BuildChildCallbacks Method6.3.2.2. The AppendFrom Callback6.3.2.3. The AppendCopyToList and AppendRoutingItems Callbacks6.3.2.4. The Transmittal Refactoring6.3.2.4.1. The AppendCopyToList Method6.3.2.4.2. The DeleteCopyToList Method6.3.2.4.3. The InsertCopyToList and InsertCopyTo Methods6.3.2.5. Unit of Work Implementation6.3.2.5.1. The PersistNewItem Method6.3.2.5.2. The PersistUpdatedItem Method6.3.2.5.3. PersistDeletedItem6.3.3. The RFI Service Implementation6.3.4. The RFI ViewModel Classes6.3.4.1. The TransmittalViewModel<T> Class6.3.4.1.1. The Constructor6.3.4.1.2. The Properties6.3.4.1.3. The Command Handler Methods6.3.4.1.4. The GetTransmittals Template Pattern Method6.3.4.2. The RequestForInformationViewModel Class6.3.4.2.1. The Constructor6.3.4.2.2. The Properties6.3.4.2.3. The Command Handler Methods6.3.4.2.4. The GetTransmittals Template Pattern Method6.3.5. The RFI View6.4. Summary
7. Proposal Requests
7.1. The Problem7.2. The Design7.2.1. Designing the Domain Model7.2.2. Designing the Proposal Request Aggregate7.2.3. Defining the Aggregate Boundaries7.2.4. Designing the Repository7.2.5. Writing the Unit Tests7.2.5.1.7.2.5.1.1. The FindProposalRequestsByProjectTest Method7.2.5.1.2. The AddProposalRequestTest Method7.2.5.1.3. The UpdateProposalRequestTest Method7.2.5.1.4. The RemoveProposalRequestTest Method7.3. The Solution7.3.1. The Proposal Request Class Private Fields and Constructors7.3.1.1. The GetExpectedContractorReturnDays Method7.3.1.2. Initializing the expectedContractorReturnDate Class Variable7.3.1.3. The ValidateInitialization Method7.3.2. The ProposalRequest Properties7.3.2.1. The Cause and Origin Properties7.3.2.2. The NumberSpecification Property7.3.2.3. The DescriptionSpecification Property7.3.3. The Validate Method7.3.4. The Proposal Request Repository Implementation7.3.4.1.7.3.4.1.1. The BuildChildCallbacks Method7.3.4.1.2. The AppendTo Callback7.3.4.1.3. The AppendFrom Callback7.3.4.1.4. Unit of Work Implementation7.3.4.1.5. The PersistNewItem Method7.3.5. The Proposal Request Service Implementation7.3.6. The Proposal Request View Model Class7.3.6.1. The Constructor7.3.6.2. The Properties7.3.6.3. The Command Handler Methods7.3.6.3.1. The NewCommandHandler Method7.3.6.3.2. The SaveCommandHandler Method7.3.6.4. The GetTransmittals Template Pattern Method7.3.7. The Proposal Request View7.3.7.1. The Transmittal User Control7.3.7.2. The RoutableTransmittal User Control7.4. Summary
8. Change Orders
8.1. The Problem8.2. The Design8.2.1. Designing the Domain Model8.2.2. Designing the Change Order Aggregate8.2.3. Defining the Aggregate Boundaries8.2.4. Designing the Repository8.2.4.1. Designing the IChangeOrderRepository Interface8.2.4.1.1. Designing the INumberedProjectChild Interface8.2.4.1.2. Designing the IAggregateRoot Interface8.2.5. Writing the Unit Tests8.3. The Solution8.3.1.8.3.1.1. The Change Order Class Private Fields and Constructors8.3.1.1.1. The ValidateInitialization Method8.3.1.2. The ChangeOrder Properties8.3.1.2.1. The OriginalConstructionCost Property8.3.1.2.2. The PreviousAuthorizedAmount Property8.3.1.2.3. The NewConstructionCost Property8.3.1.2.4. The PreviousTimeChangedTotal Property8.3.1.2.5. The DateOfSubstantialCompletion Property8.3.1.2.6. The NumberSpecification Property8.3.1.3. The Validate Method8.3.2. The Change Order Repository Implementation8.3.2.1. The BuildChildCallbacks Method8.3.2.1.1. The AppendContractor Callback8.3.2.1.2. The AppendRoutingItems Callback8.3.2.2. The FindBy Method8.3.2.3. The GetPreviousAuthorizedAmountFrom Method8.3.2.4. The GetPreviousTimeChangedTotalFrom Method8.3.2.5. Unit of Work Implementation8.3.2.5.1. The PersistNewItem Method8.3.2.5.2. The PersistUpdatedItem Method8.3.3. The Change Order Service Implementation8.3.4. The Change Order View Model Class8.3.4.1. The Constructor8.3.4.2. The Properties8.3.4.3. The Command Handler Methods8.3.4.3.1. The NewCommandHandler method8.3.4.3.2. The SaveCommandHandler Method8.3.5. The Change Order View8.4. Summary
9. Construction Change Directives
9.1. The Problem9.2. The Design9.2.1. Designing the Domain Model9.2.2. Designing the Construction Change Directive Aggregate9.2.3. Defining the Aggregate Boundaries9.2.4. Designing the Repository9.2.5. Writing the Unit Tests9.3. The Solution9.3.1. The Construction Change Directive Class Private Fields and Constructors9.3.1.1.9.3.1.1.1. The ValidateInitialization Method9.3.1.2. The ConstructionChangeDirective Properties9.3.1.2.1. The DescriptionSpecification Property9.3.1.2.2. The HasBeenTransformedToChangeOrder Property9.3.1.3. The Validate Method9.3.1.4. The TransformToChangeOrder Method9.3.1.5. The NumberedProjectChildFactory Class9.3.2. The Construction Change Directive Repository Implementation9.3.2.1. The BuildChildCallbacks Method9.3.2.1.1. The AppendTo Callback9.3.2.1.2. The AppendFrom Callback9.3.2.1.3. The AppendContractor Callback9.3.2.1.4. The FindBy Method9.3.2.2. Unit of Work Implementation9.3.2.2.1. The PersistNewItem Method9.3.2.2.2. PersistUpdatedItem9.3.3. The Construction Change Directive Service Implementation9.3.4. The Construction Change Directive ViewModel Class9.3.4.1. The Constructor9.3.4.2. The Properties9.3.4.3. The ViewModel Class Refactoring9.3.4.4. The EditableViewModel<T> Class9.3.4.4.1. The Constructors and Private Fields9.3.4.4.2. The Properties9.3.4.4.3. The CurrentObjectState Property9.3.4.4.4. The CurrentEntity Property9.3.4.4.5. The ValidateCurrentObject Method9.3.4.5. The Command Handler Methods9.3.4.5.1. The NewCommandHandler method9.3.4.5.2. The SaveCommandHandler Method9.3.4.6. The Newly Refactored TransmittalViewModel Class9.3.4.6.1. The Constructor and Private Fields9.3.4.6.2. The Properties9.3.4.6.3. The NewCommandHandler Method9.3.4.6.4. The SaveCurrentEntity Method Override9.3.4.6.5. The SetCurrentEntity Method Override9.3.4.7. The ConstructionChangeDirectiveViewModel Class Method Overrides9.3.4.7.1. The BuildNewEntity Method Override9.3.4.7.2. The SaveCurrentEntity Method Override9.3.4.7.3. The GetEntitiesList Method Override9.3.5. The Construction Change Directive View9.4. Summary
10. Synchronizing With the Server
10.1. The Problem10.2. The Design10.2.1. Redesigning the Unit of Work10.2.2. The Refactored IUnitOfWork Interface10.2.3. The new IClientTransactionRepository Interface10.2.4. The Transaction Class Implementations10.2.5. Designing the Synchronization10.2.6. Writing the Unit Tests10.2.7. The IClientTransactionRepositoryAddTest Method10.2.8. The FindPendingTransactionsTest Method10.2.9. The SetLastSynchronizationTest Method10.2.10. The GetLastSynchronizationTest Method10.3. The Solution10.3.1. Unit of Work Refactoring10.3.1.1. The Commit Method10.3.1.2. The UnitOfWork Key10.3.1.3. New Properties and Changes to the Constructor10.3.1.4. The Transaction Class Implementations10.3.1.4.1. The Transaction Class10.3.1.4.2. The ClientTransaction Class10.3.1.4.3. The ServerTransaction Class10.3.1.4.4. Data Contracts10.3.1.5. The Client Transaction Repository Implementation10.3.1.5.1. The ClientTransactionRepositoryFactory Class10.3.1.6. The ClientTransactionRepository Class10.3.1.7. The SqlCeClientTransactionRepository Class10.3.1.7.1. Constructor10.3.1.7.2. The PersistNewTransaction Method10.3.1.7.3. The FindPending Method10.3.1.7.4. The GetLastSynchronization Method10.3.1.7.5. The SetLastSynchronization Method10.3.1.8. The ClientTransactionService Class10.3.2. Synchronizing with the Synchronizer Class10.3.2.1. Constructor10.3.2.1.1. The GetLastSynchronized Method10.3.2.1.2. The SetLastSynchronized Method10.3.2.1.3. The ProcessReferenceData Method10.3.2.1.4. The IReferenceDataRepository Interface10.3.2.1.5. The ReferenceDataRepositoryFactory Class10.3.2.1.6. The IReferenceDataRepository Implementation – The SqlCeReferenceDataRepository Class10.3.2.1.7. The ProcessServerTransactions Method10.3.2.2. The Main Method – the Synchronize Method10.4. Summary
11. The Client Membership System
11.1. The Problem11.2. The Design11.2.1. Password Security11.2.2. Designing the Client Membership System11.3. The Solution11.3.1. The Client Membership System Domain Model Classes11.3.1.1. The User Class11.3.1.1.1. Class Signature and Private Fields11.3.1.1.2. The Constructor11.3.1.1.3. The Properties11.3.1.1.4. The Methods11.3.1.1.5. The ChangePassword Method11.3.1.1.6. The ChangePasswordQuestionAndAnswer Method11.3.1.1.7. The ResetPassword Method11.3.1.2. The ClientMembershipUser Class11.3.1.2.1. Class Signature and Private Fields11.3.1.2.2. The Constructor11.3.1.2.3. The Properties11.3.1.2.4. The Methods11.3.1.2.5. The PasswordAttemptFailed Method11.3.1.2.6. The PasswordAttemptSucceeded Method11.3.1.2.7. The PasswordAnswerAttemptFailed Method11.3.1.2.8. The PasswordAnswerAttemptSucceeded Method11.3.1.3. The Application Class11.3.1.4. The Client Membership System Provider Framework and Implementation11.3.1.4.1. The IClientMembershipProvider Interface11.3.1.4.2. The ProviderFactory Class11.3.1.4.3. The ClientMembershipProvider Class11.3.1.4.4. Class Signature and Private Fields11.3.1.4.5. The Constructor11.3.1.4.6. The Methods11.3.1.4.7. The SqlCeClientMembershipProvider Class11.3.1.4.8. Class Signature and Private Fields11.3.1.4.9. The Initialize Method Override11.3.1.4.10. The GetUser Method Overrides11.3.1.4.11. The Other Method Overrides of the SqlCeClientMembershipProvider Class11.3.1.5. The ClientMembershipService Class11.3.2. Client Membership System Unit Tests11.3.2.1. The Login Test11.3.2.2. The Change Password Test11.3.2.3. The Change Password Question and Answer Test11.4. Summary

Content preview from .NET Domain-Driven Design with C#: Problem – Design – Solution

Chapter 10. Synchronizing With the Server

In Chapter 1, Introducing the Project: The SmartCA Application, I stated that one of the requirements for the SmartCA application was that it must be offline capable. Now, when I say offline capable, the best example that comes to mind is Microsoft Outlook. In Microsoft Outlook versions 2003 and above, you can work connected to or disconnected from your email server and still have a good user experience. During this chapter, I would like you to keep in mind how Microsoft Outlook works in order to understand some of the design decisions presented later in the chapter.

The Problem

Thanks to using a local data store on the client, the SmartCA is definitely offline capable. Now, the challenge is to get it online and connected to the server. I am going to be calling this process of connecting to the server and transferring application data back and forth the Synchronization process.

What the SmartCA application needs is an intelligent, service-based way of synchronizing its data with the server. The user should not be bothered with any silly errors because they are not connected to the network or the Internet, they should be able to do their work, and the application should gracefully handle the transactions and pushing the data back and forth.

The Design

I also mentioned in Chapter 1 that I would be using Microsoft Synchronization Services for ADO.NET for this synchronization, but I have since changed my mind. After analyzing the problem domain further, ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.

Julian F.

Head of Cybersecurity

I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.

Addison B.

Field Engineer

I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.

Amir M.

Data Platform Tech Lead

I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.

Mark W.

Embedded Software Engineer

Design Patterns in .NET: Reusable Approaches in C# and F# for Object-Oriented Software Design

Publisher Resources

ISBN: 9780470147566Purchase book

Cloud Computing

Data Engineering

Data Science

AI & ML

Programming Languages

Software Architecture

IT/Ops

Security

Design