Welcome to the Furets !

@gdigugli – Gilles Di Guglielmo

  • Designer of sweet cooked software since 1999
  • Software Architect at

@geofberard – Geoffrey Bérard

  • RnD engineer at since 2012
  • Télécom Paris Tech Speaker

Sept 2007 - Broker Desktop Application

Sept 2008 - Broker Website Widget

Jun 2009 - Broker Directory :

Jan 2010 - Insurance Aggregator

Apr 2012 - New brand :

Sep 2012 - First TV advertising

Dec 2015 - Market leader

  • 1 website, 5 Insurance Products : Car, Health, Home, Bike, Loan
  • 1 codebase, 450k lines of code, 60k unit tests, 150 selenium tests
  • 22 Developers, 2 DevOps, 3 Architects
  • 19 production servers including Load balancers, Frontend, Backend, Databases, BI
  • 1 release per day
  • 7 years of code history
  • 2.5M quotes/year, 31% of market share

Domain Model, what do you mean ?

Moving the architecture

What you have ...

What you want ...

Que faire ?

Architect at work ...

Keying everything !

A bit of decoration

Let's start with this model...

... and transform it to a key-value model

User model

User model

User model

Account model

Account model

Account model

Account model

Account model

From domain model to key-value model

  • Step 1 : create one Enumeration with all keys
  • Step 2 : annotate your domain model
  • Step 3 : generate the key value model

Let's see the domain model & the key-value model

Step 1 : one Enumeration with all keys

  • one literal for each key
  • position (optional) : used when collections are denormalized
  • tag (optional) : used to add meta-information

Step 2 : one Annotation to annotate the domain

  • one method to retrieve the FieldId
  • one method to retrieve the Constraint

Step 3 : annotate your domain model

  • attribute, getter or setter can be annotated
  • getter and setter must follow Java naming conventions

Step 4 : generate the key value model

... Just one little issue.

Account & User ID


Account & User ID


Many key for a single attribute

  • Each key must have a unique path to retrieve its value
  • How to retrieve the right value for each field?
  • getAccount().getId()? getUser().getId()?

Solution : constraints

One for each field, specify which getter to use

Add a constraint for each annotation

  • the code generator only use the path with the specified getter
  • each field is now mapped correctly

Let the magic begin ...

Code generator under the hood

  • Execution is done using a maven plugin
  • Annotated properties are processed using Java Reflection
  • Generate handwritten style code, easy to read
  • Enable JIT optimisations by combining lambdas and enumerations
  • Lightweight pattern, designed for performance

Generation output

Generation output

An Enumeration containing metadate : type, generics type

Generation output

a CSV containing each field, path, and value type

Usages are unlimited

You can use Java 8 stream on your Domain Model !

  • FieldModel#stream() : a stream of key/value pair (FieldId/Object)
  • FieldModel#parallelStream() : parallel stream and better performance
  • Easy use a filter/map/reduce operations on a domain model

Could you write a domain model diff tool now ?

Where we use it at

  • Simple UI binding by replacing JSON model by a Dictionary (80% less code)
  • Use JSON Dictionary for client/server RPC
  • Batch and ETL with an email provider (90% less code)
  • Persistence in cassandra (from scratch with 200 lines of code for a whole model)
  • Injecting user data in selenium (40% less code)
  • Mocking our domain model in thousand of unit tests

... everything in iterative fashion during the past 2 years.

Future and ideas

  • Push as OSS our Cassandra serialisation code
  • Push some Spark samples
  • JEP 276: Dynamic Linking of Language-Defined Object Models

We need a new name ?

  • Model-Map is cool, keep it
  • YAMF: Yet Another Mapping Framework
  • OWKF: Obi Wan Kenobi Framework
  • Submit your ideas

Model-Map available on Github

  • Framework and examples
  • Apache Licence
  • Try it and contribute !

Thank You!