Softobiz
Planning, retrieval, action and verification agents coordinating under one supervisor, with a human gate on the consequential step

MULTI-AGENT SYSTEM DESIGN

Multi-agent system architecture and coordination

We design coordinated agents where a workflow needs distinct roles, shared context and controlled hand-offs. We establish when a simpler approach is enough.

  • Narrow, testable roles instead of one heroic chain
  • Typed hand-off contracts, so a bad hand-off fails loud
  • Checkpointed stages, resumable and fully traceable
THE ARCHITECTURE

The same building blocks, arranged to fit the process.

Done well, decomposition improves reliability and traceability: each agent has a narrow job, and hand-offs create natural checkpoints. Done badly, you get a sprawling swarm where errors compound silently and nobody can reconstruct what happened. The arrangement is what separates the two.

ELEMENT 01

Agents

Specialised workers, each with a narrow remit inside the process. One clear job each, easier to test, prompt, and trust.

ELEMENT 02

Coordinator

Routes work, sequences steps, and resolves hand-offs between agents. Explicit control flow with checkpointing, not emergent chaos.

ELEMENT 03

Shared state

The task context every agent reads from and writes back to. Persisted and versioned, so runs are resumable and auditable.

ELEMENT 04

Hand-off contracts

What one agent is required to pass to the next, and in what shape. Typed, validated payloads. A bad hand-off fails loud, not silent.

ELEMENT 05

Checks and critics

Agents whose job is reviewing the output of other agents. Catch errors mid-trajectory, before they compound.

ELEMENT 06

Escalation path

The defined point where the system stops and defers to a human. Consequential decisions gate to approval, always.

Prefer one well-tooled agent, or a small supervised team, over a sprawling swarm.

COORDINATION PATTERNS

The most consequential design decision on the page.

We match the pattern to the shape of the work, chosen for control, not novelty.

Supervisor / orchestrator-workerA lead agent delegates sub-tasks to specialists.Clear control and audit; the supervisor is a bottleneck you have to design well.
Hierarchical crewsWork nests: teams of agents under team leads.Scales to complex processes; more moving parts to govern.
Sequential pipelineSteps are ordered and each builds on the last.Simple and reliable; a poor fit for dynamic branching.
Group chat with a selectorSeveral agents contribute and a selector picks who speaks.Flexible for open-ended work; needs tight turn and cost limits.
Reflection / critic loopOutput quality matters more than latency.Higher accuracy; adds cost and steps, so the iterations are bounded.
Planner-executorThe task needs a plan before any action is taken.Good for long-horizon work; the plan itself must be validated.

We frequently combine these, a supervisor over specialists, each wrapping a reflection loop, rather than forcing one pattern to do everything. Because error compounds across steps, a 95%-reliable step is only about 60% reliable over ten, we decompose long tasks into checkpointed stages with validation between them.

THE POD THAT DESIGNS AND BUILDS IT

Not handed to a single prompt engineer.

Multi-agent systems are designed by a small, senior, cross-functional team, with the governance lead in the room from the start.

Agent architect1Coordination pattern, decomposition, and hand-off contracts.
Agent engineers2–3Building the agents, their tools, and the integrations behind them.
Evaluation engineer1Trajectory and step-level evals: is the system actually working.
Domain SME1, client-side or sharedGround truth, edge cases, and the definition of done right.
Governance / risk leadFractionalAutonomy lines, approval gates, and audit requirements.

Ratios are indicative and sized to the complexity of the system.

OUR APPROACH

Five steps, and the first one is challenging the design.

STEP 01

Decompose

Break the process into distinct roles, then challenge every one: can a single agent do this instead.

STEP 02

Select the pattern

Choose the coordination pattern that matches the work's shape and its risk.

STEP 03

Define contracts

Hand-off contracts and checks, so failures surface at the boundary, not three steps later.

STEP 04

Prototype the trajectory

Run it end to end and evaluate the whole trajectory before hardening anything.

STEP 05

Harden

Checkpointing, escalation gates, and observability, so the system is resumable and auditable.

FREQUENTLY ASKED QUESTIONS

What architects ask us first.

When the work contains genuinely distinct roles that benefit from checking each other: a drafter and a reviewer, a planner and an executor. If one well-tooled agent can do the job, that is almost always the more reliable choice, and we will say so.

Yes, which is why we treat every added agent as a cost, not a feature. The gain from decomposition has to outweigh the coordination and failure surface it introduces, so we design for the smallest system that works.

We evaluate the whole trajectory: tool-selection accuracy, task completion, cost, and latency per task, not just the final output. Those evals are built in before launch rather than bolted on after.

DESIGN AN AGENT TEAM THAT HOLDS UP

The smallest multi-agent system that carries your process reliably.

With the hand-offs, checks, and escalation your risk team will accept.