A journey map names each step a customer takes and the system responsible for it. That makes it two documents at once: the operating plan for lifecycle work, and the alignment artefact a technical and a commercial co-founder can both sign, because it settles who owns which step rather than who owns which tool.
Product analytics supplies the evidence. PostHog has become the default for engineering-led teams because it is open source and self-hostable and bundles product analytics, session recordings, feature flags and A/B testing in one place, and it says most of its customers never leave the free plan. Mixpanel moved to event-based pricing in February 2026, and Amplitude remains the deeper behavioural choice for larger teams. The benchmarks that make a map actionable are published: median LTV to CAC of 3.2, and CAC payback varying by contract size from about 11 months below US$5,000 ACV to about 22 months at enterprise.
