A developer who has almost completed a required product feature for a prototypeleaves the company...

According to the hybrid project management approach, which combines elements of waterfall and agile methodologies, the project manager should facilitate the collaboration and communication among the team members and adjust the scope and schedule as needed12. In this scenario, the project manager should first determine whether other cross-functional team members are able to take over the work of the developer who left the company in the middle of an iteration. This would allow the project to continue with minimal disruption and maintain the quality and value of the deliverable. If no one on the team has the skills or capacity to complete the work, the project manager should then consult with the product owner and the stakeholders to renegotiate the scope and schedule of the iteration, or to cancel the iteration and return to planning3. The project manager should avoid reviewing the backlog to reschedule the deliverable for a later iteration without involving the team and the product owner, as this would violate the agile principle of customer collaboration over contract negotiation4. The project manager should also avoid engaging with stakeholders directly to review the iteration process without involving the team and the product owner, as this would violate the agile principle of self-organizing teams4. The project manager should also avoid going to management and asking to hire a new external developer without exploring other options first, as this would incur additional costs and risks, and delay the delivery of the product feature5. References: 1: What is the Hybrid Approach in Project Management? | Hygger.io 2: Hybrid Project Management: What is it, Approach & Software - Teamhood 3: What to do when capacity is reduced in the middle of the Sprint? (e.g. Sick Leave) - Project Management Stack Exchange 4: Manifesto for Agile Software Development 5: How To Handle A Key Team Member Leaving At A Critical Project Point | IT Staffing & Technical Consulting