A correction to the original statistic
The original article asserted that 90% of startups fail in their first year without a source defining the population or the meaning of failure. That assertion and the ranked list have been removed. A useful review identifies a company's own risks, tests the assumptions and assigns responsibility for follow-up; it does not apply one percentage to every business.
Demand and cash
Check whether a defined customer will pay for the proposed solution, whether delivery costs fit the business model and how long existing cash lasts. Treat a forecast as a hypothesis until its assumptions have been tested. Prepare decisions for slower sales, delayed collection and higher costs rather than relying on a future funding round to arrive on schedule.
Execution and dependencies
Record who owns product delivery, sales, security and financial controls. Review customer concentration, supplier dependence, regulatory requirements and the evidence behind a launch date. Resolve unclear responsibilities and document a response to each material risk. These are editorial planning questions, not a statistical ranking or a claim that a particular team member causes failure.