GrowthStack, Benchmarked

A straight comparison: GrowthStack against LaunchDarkly, Optimizely, and Statsig — on architecture, not adjectives.

No inflated benchmarks. Where the tools are genuinely comparable, we say so. Where the architecture actually diverges, here's exactly how — and what it means for who owns your infrastructure.

Tier 1 — Baseline
What a credible tool in this category does
CapabilityGrowthStackLaunchDarklyOptimizelyStatsig
Feature flag targeting & percentage rollouts✓✓✓✓
Kill switch to disable a feature live✓✓✓✓
A/B and multivariate experimentation✓✓✓✓
Deterministic experiment assignment✓✓✓✓
Segment creation & targeting✓✓✓✓
Event ingestion & tracking✓✓✓✓
Tier 2 — Architecture
Where the engineering actually diverges
DetailGrowthStackLaunchDarklyOptimizelyStatsig
Evaluation happens in-process, zero network calls ✓Rules live in your own Postgres/Redis, evaluated in the same process as the request –Client-side SDKs call LaunchDarkly's servers per evaluation, by their own documentation —Not publicly specified ~Local SDK cache, synced from Statsig's cloud control plane
Assignment when targeting depends on real-time behavior ✓Segment membership is pre-computed for speed, but marries that with real-time behavioral data to stay accurate — live-behavior targeting still resolves in the same sub-5ms hot path —Not publicly specified —Not publicly specified —Not publicly specified
Flag kill propagation ✓No propagation step — single self-hosted instance, no global cache to sync ~Sub-200ms global propagation (their published figure — genuinely fast) —Not publicly specified ~"Within seconds globally" (their own wording)
Assignment / evaluation latency ✓Sub-5ms, in-process —Depends on network round-trip for client SDKs —Not publicly specified ~Sub-50ms local evaluation (their published figure)
Peak concurrent requests pending load test — Jun 26 —Not publicly specified —Not publicly specified —Not publicly specified

At the latency range above, raw differences are smaller than a human can perceive in normal use — included for technical completeness, not as a headline claim.

Tier 3 — Structural
Where it's not a features question at all
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Runs inside Claude — a PM creates segments, checks results, and kills a flag with no engineering ticket
LaunchDarkly: has MCP support, but it's built for engineers using coding assistants — not for handing control to a PM directly. Optimizely, Statsig: no MCP integration.
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Self-hosted — your data never leaves your infrastructure
LaunchDarkly, Optimizely, Statsig: all cloud-only. No self-hosted option exists for any of them today.
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Once built, it's deployed to your servers — yours to inspect and extend
LaunchDarkly, Optimizely, Statsig: closed-source SaaS. You get a UI and an SDK, not the engine underneath it.
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One-time build. No recurring license, ever.
LaunchDarkly: MAU/seat-based, annual contracts. Optimizely: custom quote, recurring. Statsig: metered by event volume, recurring.