Design the event instrumentation for Premium at scale at global scale

Problem Statement Description

Product context: Spotify is an audio streaming company; its products include music, podcasts, audiobooks, playlists, recommendations, creator tools, subscriptions, and ads.

Spotify wants to improve how it measures and understands the Premium customer journey at global scale, from discovery and trial eligibility through subscription, billing, feature usage, retention, churn, and possible reactivation. As a Technical PM, you are asked to design the event instrumentation layer that enables reliable product analytics, experimentation, personalization, marketing attribution, and business reporting across mobile, desktop, web, backend services, and partner/payment integrations.

This instrumentation must work across many countries, subscription plans, currencies, devices, app versions, privacy regimes, and user states. It should support Premium-specific workflows while also accounting for Spotify’s broader ecosystem, including free-to-paid conversion, advertiser-supported listening, podcasts, audiobooks, creator tools, and campaigns that may influence Premium acquisition or retention.

The challenge is not to propose a Premium growth strategy, but to define what should be instrumented, how events should be structured and governed, how data quality should be maintained, and how teams can safely use the data for decisions without over-collecting or violating user trust.

The experience should consider:

- Core Premium user journeys and state transitions, including eligibility, plan selection, checkout, payment success or failure, trial start, renewal, cancellation, downgrade, upgrade, and reactivation.

- Event taxonomy and schema design, including event names, required properties, identifiers, timestamps, source systems, session context, locale, platform, plan type, and subscription status.

- Data flows across clients, backend services, billing providers, experimentation platforms, marketing systems, analytics warehouses, and real-time decisioning systems.

- Reliability requirements such as deduplication, ordering, late-arriving events, offline event buffering, retries, idempotency, versioning, and backward compatibility.

- Privacy, consent, and security constraints across global markets, including data minimization, access controls, retention policies, regional compliance, and treatment of sensitive billing or identity data.

- Instrumentation for experimentation and attribution, including exposure logging, cohort assignment, campaign source, conversion windows, and guardrails against biased measurement.

- Observability and data quality monitoring, including missing-event detection, schema validation, anomaly alerts, lineage, ownership, and incident response.

- Rollout and governance approach, including documentation, developer adoption, migration from legacy events, QA, cross-functional ownership, and safe launch across platforms and regions.

Your goal is to define a scalable instrumentation design that would let Spotify teams confidently measure Premium behavior, diagnose product and revenue issues, power experimentation, and support global growth decisions while maintaining reliability, privacy, and long-term maintainability.