Business4s H2 2025 Highlights

Six more months of building practical Scala for real business problems

Another six months have flown by, and Business4s keeps quietly — but steadily — moving forward. The ecosystem continues to grow through a mix of engineering efforts, community contributions, and experimentation around how Scala can better support real-world business systems.

Below is a snapshot of what happened in the second half of 2025.

Workflows4s

Workflows4s remains our largest and most ambitious project — and the one seeing the most diverse contributions.

Web UI reaches production readiness

The Workflows4s Web UI, originally developed during Google Summer of Code by Atharva, was further polished, merged, and officially released. It is now a usage-ready, full-stack application that enables inspection and interaction with running workflows.

Feel free to check the dedicated announcement for more details.

Real-world usage example

Giovanni built llm4s-tripper, a travel planning agent combining llm4s with workflows4s. It serves both as an end-user application and a concrete example of how workflows4s can orchestrate complex, long-running, AI-driven processes.

Engine, introspection, and correctness improvements

A number of important features landed during this period:

• Workflow instance signal inspection
  Added the ability to inspect expected signals for a specific workflow instance (contributed by Watson), improving introspectability and operations.
• WorkflowInstanceEngine
  A new abstraction enabling fine-grained and extensible customization of workflows4s runtime behavior — conceptually similar to how STTP allows backend customization.
• Drafting support polished and expanded
  Drafting now covers all available operations and comes with proper documentation, thanks to substantial work by Watson.
• Stateful, durable retries
  Introduced support for stateful retries allowing for configurable strategies such as exponential backoff — spanning days, weeks, or even months — while remaining fully durable.

Effect polymorphism (long road ahead)

Łukasz started the long-term effort of making workflows4s effect-polymorphic. This is a large undertaking, but one that will ultimately make Workflows4s accessible across different Scala ecosystems and effect systems.

Static analysis via a linter

Work began on a Workflows4s Linter, leveraging the declarative nature of workflows to detect many classes of issues statically.

Early production adoption

At least three companies are now either seriously evaluating or already using workflows4s in production. While this may sound modest, adopting a workflow engine is a major architectural decision — making this milestone particularly meaningful.

Business4s as a whole & other projects

Clarifying the vision

A new About page was published, describing what Business4s is really about — taking a step back and describing our goals, approach and purpose.

The same philosophy was presented at Scala Days (kind of), focusing on practical, business-aware tooling rather than abstract language features.

DomainDocs4s

Bartek has been steadily pushing DomainDocs4s forward. Progress is incremental, but the goal is to reach a first public release next semester.

Scala Adoption Tracker

The Scala Adoption Tracker now serves as a community resource tracking real-world Scala usage. It’s our small contriubution to how Scala is perceived in the borader world.

Don’t hesitate to add your company if it’s not already there!

What’s ahead

Looking into the next months, the focus remains pragmatic:

• First release of DomainDocs4s
• Proper public announcement of Forms4s
• Continued iteration and hardening of Workflows4s
• More focus and love toward Decisions4s (I strongly believe it is the most under appreciated and under adopted project in the ecosystem!)
• A lot of ideas for the next Google Summer of Code — with multiple potential co-mentors already interested in joining.

Closing

Business4s strarts to be shaped far by contributors than by myself, which is one of the most important goals of mine.

If you’re curious, opinionated, or simply want to build Scala tools that solve real business problems, there is plenty of room to get involved. Look around the repos, come to our Discord or reach out to me directly!