CONCEPT Cited by 1 source
Inner sourcing¶
Definition¶
Inner sourcing (or innersource) is the application of open-source-style contribution practices inside a single company. Teams that do not own a platform contribute changes to it through the same review, testing, and integration discipline that an external open-source contributor would use — but with all the contributors working for the same employer and the platform remaining proprietary.
The canonical practitioner reference is O'Reilly's Adopting Innersource (Clare-Thayer, 2019), which Zalando cites directly (Source: sources/2022-09-28-zalando-more-editorial-content-please).
Why it matters for platforms¶
Platforms thrive when they can be extended by teams that don't own the platform — the platform team cannot anticipate every content type, every integration, every per-domain feature. Inner sourcing formalises the contribution model so that:
- Extension is additive, not invasive. New capability comes in as a new module / plugin / renderer / mapping, not as a fork or a monolithic rewrite.
- Review discipline is explicit. Contributors submit code the platform team reviews, not out-of-band emails or Slack threads.
- Ownership is clear. The platform team owns the platform; contributing teams own their extensions.
- Success is measurable by whether contributions actually land from other teams, not by promises in the platform's design docs.
Canonical wiki instance — Zalando Sustainability Certificate¶
Zalando's Landing Pages stack was originally built by the Zalando Marketing Services (ZMS) Landing Pages team. The Sustainability team — a different team with different goals (long-lived sustainability information rather than short-lived marketing campaigns) — contributed the Sustainability Certificate module as a self-contained change touching three layers:
- A new Contentful entry-type (the certificate module).
- A new mapping in the
Contentful proxy from
that entry-type to the existing
CollectionGraphQL type, including the cross-surface enrichment call to the same certificate backend the PDP uses. - New UI components on web + app rendering the module.
No existing layer had to change. The contribution shape is canonicalised as patterns/inner-sourced-module-extension.
Post quote: "the implementation of the additional modules by the Sustainability team was a successful example of inner sourcing."
Adjacent Zalando inner-sourcing discipline¶
patterns/template-project-nudges-consistency (from the Kotlin-ADOPT ring post) is a complementary pattern — the platform ships template projects that bootstrap new services with idiomatic defaults. Template projects are an inner-sourcing enabler: contributions from other teams start from known-consistent scaffolding.