Consumer fintech · 120 engineers
Cut support p95 latency from 9.2 s to 1.4 s — same prompts, same tools, same model.
A US consumer fintech replaced their LangGraph supervisor with Agentmatic. The graph, prompts, and tools stayed identical; only the runtime changed. Latency dropped 6.5×.
Customer support agent · Published May 15, 2026
Outcomes
- Support p95 latency 9.2 s → 1.4 s on the same OpenAI model.
- Compute spend on the support service down 38% (smaller event-loop, fewer worker pods).
- Zero customer-facing regressions across 4,200 conversations in the first week.
- Migration took one engineer 90 minutes total.
The setup
A growing fintech with a customer support agent built on LangGraph: supervisor routes to docs / billing / escalation specialists; each specialist is a ReAct agent with 4–8 tools; PostgresSaver for HITL on refunds.
The graph was already good — clean separation, well-tuned prompts, refunds gated behind a human approval interrupt. The problem was responsiveness. Average p95 was 9.2 seconds; users churned mid-conversation.
What they changed
One import.
# Before
from langgraph.graph import StateGraph, START, END
# After
from agentmatic import StateGraph, START, END
Then pip install agentmatic, replaced langgraph in requirements.txt, ran their existing test suite — all 312 tests passed without modification. Deployed behind a 5% canary.
What they saw
Within a week the canary was at 100%. The numbers from the first 4,200 conversations:
| Metric | Before (LangGraph) | After (Agentmatic) | Δ |
|---|---|---|---|
| p50 latency | 2.8 s | 0.6 s | 4.7× |
| p95 latency | 9.2 s | 1.4 s | 6.5× |
| p99 latency | 14.1 s | 2.7 s | 5.2× |
| Worker pods | 18 | 11 | -39% |
| Daily compute spend | $1,420 | $880 | -38% |
The end-to-end latency wins come from the multi-agent shape — a supervisor + 3 specialists is high-graph-density, so the Rust runtime’s framework-overhead reduction shows up directly.
What they didn’t change
- Same OpenAI model (gpt-4o).
- Same prompts (zero edits).
- Same tools (zero edits).
- Same Postgres checkpoint store (wire-compatible).
- Same LangSmith tracing (wrapped via
as_langchain_runnable()).
Their take
“It felt suspicious. We’ve never had a perf optimization that didn’t require a redesign. We expected to debug subtle behavior differences for a week — but the eval suite passed and the canary numbers were clean within hours.”
— Staff engineer, platform team
Why they’re featured
Two reasons: (1) the migration was a single file change, (2) the win was load-bearing for the business — sub-2-second support response is a churn-prevention threshold.
This story is anonymized at the customer's request. Industry, scale, and workflow details are accurate; identifying details have been changed.