I Built an ETL Platform Solo. 18 Phases, 1,400+ Tests, One Month

Описание и применение

Разработчик создал полноценную ETL-платформу за месяц, разбив проект на 18 фаз, применяя TDD и строгую архитектуру слоев, что позволило избежать регрессий и обеспечить масштабируемость.

Задача

Solo developers often struggle to build complete ETL platforms due to scope creep, lack of structure, and insufficient testing, leading to regressions and incomplete features.

Результат

The solo developer delivered a production‑ready ETL platform in one month, achieving 1,424 tests, a clean layered architecture, and an open‑core plugin system, all while maintaining strict scope control and TDD discipline.

Рабочий процесс

• Define 18 incremental phases with 1–3 day deliverables
• Implement each phase following strict TDD: write failing test, code, commit
• Use layered architecture: models, services, tasks, UI state, UI pages
• Integrate dlt for extraction, dbt-core for transformation
• Orchestrate with Celery and APScheduler
• Wrap UI in Reflex
• Add security tests for SQL injection, XSS, path traversal, auth attacks
• Implement public schema with org_id filtering for multitenancy
• Add hooks system for open‑core plugin architecture
• Run CI to catch regressions before PR review
• Iterate until phase 18 completes without breaking earlier phases

Доказательства

I had 1,424 tests across 73 test files — covering models, services, tasks, security, end-to-end flows, and even multi-tenant isolation.

Источник

Each phase had a clear deliverable and a short feedback loop. If I couldn't finish a phase in three days, the scope was wrong, not the timeline.

Источник