Roadmap

This page tracks what has shipped, what is planned, and what is explicitly out of scope. It is updated with each release.

Roadmap Priorities

Items in v1.1 Planned are committed for the next release. Items in v2.0 Ideas are under consideration and may change based on community feedback.

v1.0 — Shipped

The v1.0 release provides a stable foundation for type-safe pipeline orchestration.

Core

• Type-safe pipeline compilation with field-level validation
• Record type algebra: merge (+), projection ([]), field access (.)
• Candidates<T> batch type with merge and projection
• Optional<T> with guard expressions (when) and coalesce (??)
• Union types (A | B)
• Branch expressions (branch { condition -> value, otherwise -> default })
• Lambda expressions and higher-order functions (filter, map, all, any)
• String interpolation with escape sequences
• Namespace imports with aliasing (use stdlib.math as m)

Runtime

• Automatic parallelization from DAG structure
• Per-call resilience: retry, timeout, delay, backoff, fallback
• Caching with configurable TTL and pluggable backends
• Rate limiting (throttle) and concurrency control
• Lazy evaluation and priority scheduling
• Error handling strategies (on_error: skip | log | fail)
• Graceful shutdown with drain timeout
• Cancellable execution via Cats Effect fibers

Infrastructure

• HTTP API with auth, CORS, and rate limiting middleware
• LSP server with diagnostics, autocomplete, hover, and go-to-definition
• Web dashboard with DAG visualization and execution history
• VSCode extension with syntax highlighting and integrated LSP
• Structured health checks (liveness, readiness, detail)
• SPI extension points: metrics, tracing, execution listener, cache backend, execution storage
• Docker and Kubernetes deployment support

v1.1 — Planned

Focus: developer experience and onboarding.

• CLI tool — constellation init, constellation run, constellation validate for working with pipelines outside the JVM
• Giter8 project template — sbt new constellation/constellation.g8 for quick project scaffolding
• Additional standard library modules — date/time operations, JSON manipulation, HTTP client module
• Expanded test coverage — property-based tests for the type checker, fuzzing for the parser
• Performance baseline CI — automated benchmark regression checks in CI

v2.0 — Ideas

These are directions under consideration, not commitments.

• Distributed execution — run pipeline steps across multiple JVM nodes with work-stealing
• Streaming mode — support unbounded input streams alongside request/response pipelines
• Python/TypeScript module SDKs — define modules in languages other than Scala
• Visual pipeline editor — drag-and-drop pipeline composition in the web dashboard
• Pipeline versioning — deploy multiple versions of a pipeline with traffic splitting

Explicitly Out of Scope

Not a General-Purpose Tool

Constellation is purpose-built for type-safe pipeline orchestration. If your use case matches one of the items below, consider the suggested alternatives instead.

These are things Constellation Engine is not intended to become:

Area	Rationale
General-purpose programming language	Constellation-lang is a DSL for pipeline composition, not application logic
Distributed compute framework	Use Spark, Flink, or Ray for distributed data processing
Workflow scheduler	Use Temporal, Airflow, or Dagster for long-running multi-step workflows with human-in-the-loop
Database or storage layer	Constellation orchestrates calls to external systems; it doesn't store data

How to Influence the Roadmap

Want a Feature?

Open a GitHub Issue with the enhancement label and describe your use case. Issues with clear business value and community upvotes are prioritized for future releases.

• Feature requests — open a GitHub Issue with the enhancement label
• Bug reports — open an issue with reproduction steps
• Contributions — see the Contributing Guide for how to submit changes
• Discussion — comment on existing issues to add context or vote with a thumbs-up reaction