InfoQ

InfoQ

News

My Bookmarks

Login or Register to enable bookmarks for unlimited time.

The content has been bookmarked!

There was an error bookmarking this content! Please retry.

InfoQ Presentation: Eric Evans on Domain Driven Design - Putting the Model to Work

Posted by Niclas Nilsson on Nov 08, 2007

Sections
Architecture & Design,
Development,
Enterprise Architecture
Topics
Architecture ,
Design ,
Modeling ,
Object Oriented Design ,
Language
Tags
Domain Driven Design ,
JAOO Conference

Why bother with models?

Many development teams undertake modeling, yet they often end up with little more than a data schema which does not deliver on the productivity promises for object design. What does it take to make a domain model truly pull its weight and positively transform a project? To do that we need a model that is not just a diagram or an analysis artifact, but that provides the very foundation of the design, the driving force of analysis, even the basis of the language spoken on the project.

In this talk, Eric Evans outlines some of the foundations of domain-driven design:

  • How models are chosen and evaluated
  • How multiple models coexist
  • How the patterns help avoid the common pitfalls, such as overly interconnected models
  • How developers and domain experts together in a domain-driven design team engage in progressively deeper exploration of their problem domain and make that understanding tangible as a practical software design.

View the 60-minute InfoQ exclusive presentation Domain-Driven Design - Putting Models to Work to learn how to tackle complexity in software. Remember - the most critical complexity of most software projects is understanding the business domain itself.

18 comments

Watch Thread Reply

where is 2nd part by Yale Li Posted
Re: where is 2nd part by Yale Li Posted
Re: where is 2nd part by Yale Li Posted
Re: where is 2nd part by Diana Plesa Posted
Re: where is 2nd part by Sddd jkljlkjl Posted
A great talk by Yale Li Posted
Re: A great talk by Rolf Lampa Posted
Player stops by Ivo Limmen Posted
Re: Player stops by Floyd Marinescu Posted
Download Video by Hadikusuma Wahab Posted
Eager to see part two by Corin Lawson Posted
Re: Eager to see part two by Rolf Lampa Posted
Re: Eager to see part two by Rolf Lampa Posted
Re: Eager to see part two by Diana Plesa Posted
Very good - now we wait for part THREE by Rolf Lampa Posted
Re: Very good - now we wait for part THREE by Niclas Nilsson Posted
Re: Very good - now we wait for part THREE by Lo Kuei-yang Posted
size of countries by Sebastian Dietrich Posted
  1. Back to top

    where is 2nd part

    by Yale Li

    I do not see any control for pause/forward/play recorded presentation. It completed Eric's first part, but it is not playing the 2nd part of the talk. Do i need to wait for 30 minutes for the break between 2st part and 2nd part?

  2. Back to top

    Re: where is 2nd part

    by Yale Li

    well, i found the controls by mouse over the video,

  3. Back to top

    Re: where is 2nd part

    by Yale Li

    so i found the end of the talk, i guess that the 2nd part of talk is not posted yet. am I right?

  4. Back to top

    A great talk

    by Yale Li

    this is a great talk i recommend for everyone. Very well put and clearly explained concepts

  5. Back to top

    Re: A great talk

    by Rolf Lampa

    Yes, it seems to be based on true experience.

    I once used other names in this domain, like Trip, TripEvent(Stops), TripSections(Legs) etc, a bit abstract perhaps, but generic. Downside with "generic names" is that it doesn't tend to sound very much like the "domain language", which is important for communicating core concepts with the domain experts, upside with generic names is (for the designer) that the emerging model "invites" to discovering generic patterns and "meta solutions" (a kind of a "the trees don't obscure the forest effect" if undressing the names of domain specific implementations). This in turn increases "insights" in the problem domain.

    And yes, try to get as deep into the problem domain as possible by discussing many and all aspects with domain experts. Don't stop at the first bright idea. I like that.

    But, OTOH, do NOT assume that the domain experts _fully_ understand the principles involved!, instead DO assume that they know (the best) how to do the job the way they currently do it (which is not exactly the same...).

    What I am saying is that a thorough analysis in the pre-design stage is an unique occasion also for the domain experts (usually the end customer) to learn to even better understand the problem domain(s) at hand, and from that follows a unique opportunity to potentially *improve* the business concept(s). Well, that's my experience anyway.

    It would be really interesting to hear also the other half of the lecture, hopefully the second part will also be uploaded?

  6. Back to top

    Re: where is 2nd part

    by Diana Plesa

    Hi Yale

    Yes you're right. the second part of the talk will be published soon:)

  7. Back to top

    Player stops

    by Ivo Limmen

    Hi,

    Can the video also be downloaded somewhere? My connection fails sometimes and the player wants to restart and I am not able to seek to the point where the player stopped the last time.

  8. Back to top

    Re: Player stops

    by Floyd Marinescu

    Unfortunately not, however we are working on a fix but it may not be around for another couple of months.

  9. Back to top

    Download Video

    by Hadikusuma Wahab

    Hi Ivo , you should try OrbitDownloader. Its free and can download any types of video :)

  10. Back to top

    Eager to see part two

    by Corin Lawson

    A very good talk. Despite Evans' moments of awkwardness he gave a coherent and well expressed presentation with a thought-out example.

    As a practitioner the new and exciting bit was at the end: many models can work to our advantage. Often I will consider 'the context' of a system first, define the basics of 'it' and move on. Maybe, next time I will spare some thought for the many contexts and workout a framework for each of them. I can't wait to see how to make it work, in part two... how/where will it be advertised? Will there be a link from this presentation?

  11. Back to top

    Re: Eager to see part two

    by Rolf Lampa

    >> Despite Evans' moments of awkwardness

    Wow this really was an idiotic claim!

    What if Mr. Evans was only thinking very deep inbetween, trying to increase value by trying to avoid confusing you by introducing too much complexity too early?

    He's actually doing very good. He's allowing things to sink in.

    Would you know exactly why his very humble and pleasant performance sometimes makes a short brake for a moment of deeper reflexion?

    This is what designer's do. They stop and think where other ruch ahead and causes,um... "all sorts".

    Disregard this stupid comment.

    // Rolf Lampa, Sweden.

  12. Back to top

    Re: Eager to see part two

    by Rolf Lampa

    >> Disregard this stupid comment.


    Well... this comment doesn't look very clever either...

    It should of course have read:
    "Disregard the quoted stupid (and mean) comment, by Corin Lawson"

  13. Back to top

    Re: where is 2nd part

    by Sddd jkljlkjl

    Great how different the interpretation of "soon" can be.

  14. Back to top

    Re: Eager to see part two

    by Diana Plesa

    Part two is now online on InfoQ: www.infoq.com/presentations/strategic-design-evans

  15. Back to top

    Very good - now we wait for part THREE

    by Rolf Lampa

    Part two is now online on InfoQ: www.infoq.com/presentations/strategic-design-evans


    Thanks. This second part was very good as well. What's really worth considering in any enterprise system is the approach to separate a system into :

    - Core Domain(s)
    - Sub Domains (generic or supporting dittos)

    Very good talk and recommendations, with example of how to people tend to put too much effort into the wrong (sub) domains and so end up with a crappy designed Core Domain.

    Eric demonstrates his experience - and matureness - as a designer of "real world business systems" when he points out that business systems actually has to incorporate ALSO messy and chaotic parts (for example for varying types and quality of in-data to the system) since this is an essential part of supporting (solving) the REAL business problems/situations. But - and here comes the point - although "messy parts" are unavoidable, make sure to keep those messy parts (domains) out of the "clean" and well designed Core Domain(s)!

    No surprise, very good talk again! I look forward to seeing also the third (last?) part. :)

    // Rolf Lampa

    PS: Btw, was this video recorded in Sweden? (I think I saw the text "musikhuset" (music house) on that blue sign).

  16. Back to top

    Re: Very good - now we wait for part THREE

    by Niclas Nilsson


    PS: Btw, was this video recorded in Sweden? (I think I saw the text "musikhuset" (music house) on that blue sign).


    In Denmark actually, at the JAOO conference.

    Kind regards
    Niclas

  17. Back to top

    Re: Very good - now we wait for part THREE

    by Lo Kuei-yang

    where can i download the slides...?
    please...

    Thank you so much...

  18. Back to top

    size of countries

    by Sebastian Dietrich

    unfortunately Eric is totally wrong concerning the size of countries on his map since it is no map that projects the size of a country or contintent correctly

Educational Content

New-age Transactional Systems - Not Your Grandpa's OLTP

John Hugg discusses high volume transaction processing applications with high and low frequency profiles, and how VoltDB can be used for that purpose.

Cool Code

Kevlin Henney examines code samples to see what can be learned from them starting from the premise that one won’t write great code unless he knows how to read it.

Collaboration: At the Extremities of Extreme

Jason Ayers share the observations he made watching a team of developers collaborating in real time on the same code base, pushing XP, pair programming and continuous integration to their extremes.

Yesod Web Framework

Michael Snoyman presents Yesod, a web framework written in Haskell and containing a web server, templating, ORM, libraries (templating, gravatar, etc.).

Transactions without Transactions

Richard Kreuter and Kyle Banker on how to avoid classical RDBMS transactional systems by using compensation mechanisms, transactional messaging or transactional procedures.

Attila Szegedi on JVM and GC Performance Tuning at Twitter

Attila Szegedi talks about performance tuning Java and Scala programs at Twitter: how to approach GC problems, the importance of asynchronous I/O, when to use MySQL/Cassandra/Redis, and much more.

10 tips on how to prevent business value risk

One category of risk that project teams need to ensure they address is business value failure – delivering a product that fails to provide value for the business investor.

Interview: Software Systems Architecture: Working With Stakeholders Using Viewpoints and Perspectives

InfoQ spoke to the authors of Software Systems Architecture on a couple of new topics, the System Context viewpoint and Agile, which have been added to the second edition.