Composer

Composer

Composer: The Orchestration Platform for Quantum-Classical Execution

Composer is Qoro Quantum’s unified platform for orchestrating, scheduling, and executing quantum workloads across heterogeneous hardware and simulators. It encompasses several sub-components that together turn complex quantum-classical workflows into efficient, executable schedules — optimized for performance, reliability, and cost.

As quantum infrastructure grows more fragmented and varied (from NISQ-era hardware to high-fidelity simulators), Composer provides the logic required to make smart, context-aware decisions about where, when, and how to run each part of a quantum program.

Composer Components

Composer Gateway

The cloud-facing REST API that serves as the entry point for all workloads submitted to the platform. It handles:

  • User authentication and API key management
  • Job submission, status queries, and result retrieval
  • Workload metadata management and routing to downstream services

Composer Resource Allocation

The intelligent, network-aware scheduler that analyzes available computing resources and assigns workloads optimally:

  • Routes simpler jobs to simulators
  • Offloads larger circuits to quantum hardware
  • Manages queue times, resource constraints, and hardware fidelity
  • Adapts to multi-vendor environments and cloud-based quantum access

Composer Orchestrator

The job orchestration engine that coordinates hybrid jobs across distributed infrastructure:

  • Manages job lifecycle through a multi-queue architecture (scheduling, buffering, transmission, response)
  • Interfaces with Maestro for simulation tasks via AWS SQS
  • Distributes tasks to QPU hosts and aggregates results
  • Monitors the computing network for state-aware processing

Composer Interfaces

The multi-vendor QPU access layer that provides unified connectivity to quantum hardware:

  • Supports IBM, AWS Braket, IQM, and LRZ backends
  • Handles circuit transpilation, submission, and result retrieval for each vendor
  • Provides error mitigation (M3), circuit compression, and batch processing
  • New backends can be added through a simple worker interface

Key Capabilities

Circuit Cutting and Aggregation

For circuits too large to fit on a single quantum device, Composer can:

  • Cut circuits into smaller, independently executable fragments
  • Insert classical stitching logic for reconstruction
  • Aggregate results via post-processing to yield the final output

Circuit Packing

Quantum hardware is often underutilized due to uneven circuit sizes. Composer introduces circuit packing to optimize for hardware utilization:

  • Identifies unused qubits on target hardware
  • Packs multiple compatible circuits together into one larger circuit
  • Reduces overhead and maximizes throughput on constrained devices

This is especially useful in hybrid workloads or batched execution scenarios where many small circuits must be executed efficiently.

When to Use Composer

Use Composer when your quantum workloads:

  • Span multiple devices, hardware types, or geographic locations
  • Exceed current hardware qubit limits
  • Require queue-aware or latency-sensitive scheduling
  • Include a mix of simulable and hardware-only tasks
  • Can benefit from smart job packing to reduce cost or idle time

Composer works in concert with Maestro and Divi, feeding optimized schedules to simulation or hardware backends, and seamlessly integrating with Divi’s parallel execution model.