# Middleware Building Blocks for Workflow Systems

## TL;DR

This paper introduces a building blocks approach for designing scientific workflow systems, exemplified by RADICAL-Cybertools, emphasizing modularity, integration, and applicability across diverse high-performance computing platforms.

## Contribution

It presents a set of design principles and building blocks that facilitate the development and integration of scientific workflow systems on HPC platforms.

## Key findings

- Design principles support scientific workflows on HPC
- Building blocks enable system integration and unification
- RADICAL-Cybertools successfully applied in various case studies

## Abstract

This paper describes a building blocks approach to the design of scientific workflow systems. We discuss RADICAL-Cybertools as one implementation of the building blocks concept, showing how they are designed and developed in accordance with this approach. This paper offers three main contributions: (i) showing the relevance of the design principles underlying the building blocks approach to support scientific workflows on high performance computing platforms; (ii) illustrating a set of building blocks that enable multiple points of integration, "unifying" conceptual reasoning across otherwise very different tools and systems; and (iii) case studies discussing how RADICAL-Cybertools are integrated with existing workflow, workload, and general purpose computing systems and used to develop domain-specific workflow systems.