The document discusses the Java Platform Team at Picnic which aims to boost developer effectiveness. It does this through centralized Maven configuration, shared libraries, and automation tools for tasks like dependency management, static analysis, and migrations. This includes open sourcing tools like an Error Prone support library. The team also discusses consistency through code formatting and shared code libraries.

1. Rick Ossendrijver
Boosting developer effectiveness
with a Java Platform team

2. 2 • 17-January-24
Migrate!

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TestNG -> JUnit

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Your Product Owner…

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Automation is key

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Picnic’s Java Platform Team
1
Centralized Maven configuration
2
Agenda
Dependency management
3
Shared libraries
4
Static analysis and automation tooling
5

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Picnic

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Picnic Tech
300
Engineers
35
Teams
5M
Lines of code
8
Years

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Our goal
Boost developer effectiveness
Minimal overhead
Focus on business logic
Autonomy
Openness

10. Developers
Building blocks for
developers
Multiplier effect
Convention over
configuration
Coding standards
Best practices
Centralized
configuration
Automation
Developer productivity Uniformity
Code quality
Reducing technical
debt
Migrations
10

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Java Platform Team
40 modules
Shared libraries Developer tooling
CI / CD
Monitoring

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Picnic’s Java Platform Team
1
Centralized Maven configuration
2
Agenda
Dependency management
3
Shared libraries
4
Static analysis and automation tooling
5

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Picnic Java Support Modules
Maven Parent POM
Shared Libraries
Tools

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Plugins

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Maven license plugin
[WARNING] License: 'Affero General Public License (AGPL)'
used by 1 dependencies:
- Example dependency that uses AGPL.
(com.example.dependency:example:12.1.3 -
https://github.com/example/dependency)
[...]
[ERROR] Failed to execute goal
org.codehaus.mojo:license-maven-plugin:2.3.0:add-third-pa
rty (check-third-party-licenses) on project picnic-meta:
There are some forbidden licenses used, please check your
dependencies.
[...]

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Profiles

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Picnic’s Java Platform Team
1
Centralized Maven configuration
2
Agenda
Dependency management
3
Shared libraries
4
Static analysis and automation tooling
5

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Maven dependency management

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Maven dependency management

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Dependency Upgrades at Picnic
Assign reviewers
Labels
Package managers
Automerge
Renovatebot / renovate
Universal dependency update tool that
fits into your workflows.

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21

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Maven enforcer plugin
[ERROR] Rule 1: DependencyConvergence failed with message:
[ERROR] Failed while enforcing releasability.
[ERROR] Dependency convergence error for
com.google.guava:guava:jar:31.1-jre paths to dependency are:
[...]
[ERROR] +-tech.picnic.example:example-api:jar:0.0.0-SNAPSHOT
[ERROR] +-com.google.guava:guava:jar:31.1-jre:compile
[ERROR] and
[ERROR] +-tech.picnic.example:example-api:jar:0.0.0-SNAPSHOT
[ERROR] +-com.google.truth:truth:jar:1.1.3:compile
[ERROR] +-com.google.guava:guava:jar:32.1.3-jre:compile

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Maven dependency plugin
[INFO] --- maven-dependency-plugin:3.6.1:analyze-only
(analyze-dependencies) @ cache-support ---
[ERROR] Unused declared dependencies found:
[ERROR] com.google.guava:guava:jar:32.1.3-jre:compile
[...]
[ERROR] Failed to execute goal
org.apache.maven.plugins:maven-dependency-plugin:3.6.1
:analyze-only (analyze-dependencies) on project
cache-support: Dependency problems found

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Picnic’s Java Platform Team
1
Centralized Maven configuration
2
Agenda
Dependency management
3
Shared libraries
4
Static analysis and automation tooling
5

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Shared Libraries

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Shared Libraries

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Picnic’s Java Platform Team
1
Centralized Maven configuration
2
Agenda
Dependency management
3
Shared libraries
4
Static analysis and automation tooling
5

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Consistency
“The ratio of time spent reading versus writing is well over 10 to 1.”
- Robert C. Martin

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Static analysis
checkstyle/checkstyle
Helps programmers write Java code
that adheres to a coding standard.
SonarSource/sonarqube
Continuous Inspection.

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Automation
Google/google-java-format
Reformats Java source code to comply
with Google Java Style.

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Open-source static analysis
Automated bug fixing
500+ Error Prone checks
Error Prone
Google/error-prone
Catch common Java mistakes
as compile-time errors

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Picnic open-sourced: Error Prone Support!
800+ Refaster rules
40+ Error Prone bug checks
https://error-prone.picnic.tech

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Error Prone BugPattern

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Refaster rule

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Refaster

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ArchUnit
https://www.archunit.org
▪ Architecture rules
▪ API
▪ Domain logic
▪ Freezing
b a r

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ArchUnit
https://www.archunit.org

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OpenRewrite
Large scale refactoring
Recipes
Migrations

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OpenRewrite
https://docs.openrewrite.org/recipes/java/spring/boot3/upgradespringboot_3_0

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Spring Boot 2 -> 3 migration
We migrated over 3M lines of code in 70+ repositories!

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The Experience for Developers
- Save time
- Upgrade policy
- Validating upgrades

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The fellowship of the Java Platform Team
Jarmila Kaiser Oksana Evseeva
Pieter Dirk Soels
Luca Hennart Nathan Kooij
Rick Ossendrijver Stephan Schroevers
Picnic
Lexicographically ordered, how we like it.

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Questions and feedback!
blog.picnic.nl
https://error-prone.picnic.tech
join.picnic.app
rickie rick_ossies