Freelance Data Engineer (Postgres / System Integration)

About juni: JUNI is a non-profit ecosystem for science and spin-offs in Berlin. We operate our programs across seven SaaS tools — newsletter, events, community, CRM, forms, applications, coworking — backed by a Postgres database intended to be the single source of truth for every individual. The database is everything: one resolved record per person and per organization, one append-only row per interaction, and a deterministic way to determine which person an incoming payload belongs to. The goal is to make the journey from the first touchpoint to a milestone measurable. The connection layer between the tools and this database is what you will build. Your responsibilities: Building the layer that connects our systems with a database — in both directions — and helping us get the data model right. The shape of the data is largely set, and every new system puts it to the test. Sources often disagree on what counts as a person, when something happened, and whether they reported it twice. Clarifying this — and recognizing when the model needs to be adapted rather than bending it to fit a source — is the core of the work. We are looking for someone to think this through with us and argue for a specific design, rather than just implementing what is specified. Your profile: Scope: Inbound. Every system into the database. Multiple pipelines per system, as sources report very different things. Identity resolution.