Meridian
Runs back-office workflows end to end across 42 specialised agents, with an autonomous supervisor that can halt and roll back mid-flight.
Engineering highlights
The core architectural breakthroughs.
High-scale engineering demand distilled into four verified production milestones.
Orchestrated via Temporal state machines across 31 enterprise tools
Zero-drift transaction throughput with 99.85% completion rate
Cryptographic reverse-saga rollback guarantees zero phantom ledger writes
Weekly manual interventions dropped from 4,200 to 84 cases
Executive overview
The engineering challenge & solution.
The client handled over 18,000 complex daily back-office transactions spanning 31 legacy SaaS tools, banking portals, and internal ERP systems. Previous attempts using naive LLM agent loops consistently failed: when an agent encountered an intermittent 504 timeout on step 8 of a 12-step settlement process, the agent hallucinated missing data or retried destructively, creating phantom duplicate ledger entries and corrupting accounting records.
We engineered an asynchronous multi-agent orchestration mesh powered by Temporal and PostgreSQL. Workflows are broken into deterministic state-machine graphs where 42 purpose-built micro-agents handle specialized tasks (e.g., invoice OCR, tax calculation, sanction screening, ledger reconciliation). A standalone Supervisor Agent continuously validates intermediate state contracts before triggering downstream tools.
Engineering governance
The three non-negotiables.
These are the architectural constraints that shaped every boundary — no trade-offs or compromises permitted.
Atomic Rollback Guarantee
Every workflow step must define an idempotent compensatory action; if step 9 fails, steps 1 through 8 must roll back deterministically.
Cryptographic Event Sourcing
Every LLM decision, token prompt, tool parameter, and external response must be logged into an append-only verifiable audit trail.
Zero Human Babysitting
An autonomous supervisor must evaluate contract schemas and business invariant rules before any database mutation is committed.
Eliminating Phantom Side-Effects in Cascading Multi-Agent Failures
When an agent interacts with external non-transactional REST APIs, traditional ACID rollback does not exist. If a funds-transfer API succeeded but the downstream notification service timed out, a naive restart would execute a duplicate funds transfer.
We implemented a distributed Saga Execution Engine with cryptographic state leases. Every external tool is wrapped in an anti-corruption facade that registers a two-phase compensatory reversal handler in Redis. If the Supervisor detects an invariant violation, it pauses the execution graph and fires the reverse-saga sequence in exact reverse order, restoring external systems to zero-drift parity.
Request lifecycle
How data moves through Meridian.
Production verification
Measured outcomes in production.
Every metric below was captured under real production traffic and audited against historical baseline data.
Operational resilience
Automated safety guardrails.
Systems fail in production. Here is how Meridian survives network partitions, upstream timeouts, and anomalous inputs without human intervention.
Temporal Saga State Engine
Guaranteed durability and automatic compensation on network partitions.
Deterministic Tool Sandbox
External API calls must pass strict Zod schema validation before firing.
Dead-Letter Auto-Quarantine
Unresolvable edge cases isolated without blocking parallel execution lines.
Next step
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