The document discusses organizational structures used by 4 top startups:
- Zappos initially adopted a holacratic structure but later reintroduced some hierarchy due to implementation challenges.
- Buffer tried a fully flat structure but found it overwhelming and brought back some guidance; they now use flexible "task forces".
- Zapier implemented management early and uses small autonomous teams and transparency between teams.
- Basecamp focuses on flexibility over structure, using 6-week project sprints without project managers.
Overall the document advocates for flexibility and transparency over rigid hierarchy for startups.