Assumptions as code: SiriusXM’s approach to platform prioritization

Eleanor Millman, Senior Staff Product Manager, and Mina Tawadrous, Associate Director of Platform Engineering at SiriusXM, join host Justin Reock to discuss how platform teams can scale prioritization without relying on revenue.They share how SiriusXM moved beyond RICE to build a custom framework for internal platforms, using weighted factors like developer speed, reliability, cost, and trust to guide decisions across teams.The episode also explores their concept of “assumptions as code,” in which teams store and reuse assumptions in a central repository to reduce misalignment and improve decision-making, with AI helping to surface and validate those assumptions.They close with how this system is shaping SiriusXM’s 2026 prioritization approach and what it signals about a broader shift toward builder-driven product development.Where to find Eleanor Millman: • LinkedIn: https://www.linkedin.com/in/eleanor-millman-98b10350Where to find Mina Tawadrous: • LinkedIn: https://www.linkedin.com/in/mina-tawadrous Where to find Justin Reock:• LinkedIn: https://www.linkedin.com/in/justinreockIn this episode, we cover:(00:00) Intro(01:17) Mina’s role and path into platform engineering(02:03) Eleanor’s background and shift into product(03:15) Scaling prioritization across platform engineering teams(05:41) Aligning platform priorities with stakeholders(09:08) Evolving RICE into a platform-specific prioritization framework(11:33) Iterating on the prioritization framework over time(16:57) How the framework, data, and conversations drive alignment(19:06) Storing assumptions as code in a central repository(26:47) Resolving assumption conflicts with user interviews(30:47) How stored assumptions integrate with AI workflows(35:30) Standard mode and different user personas(37:20) The industry shift towards builders(41:04) The challenges of platform engineering(43:36) How SiriusXM is prioritizing in 2026Referenced:• Measuring AI code assistants and agents• SiriusXM • VMware• How SiriusXM revamped their platform and developer experience• RICE Scoring Model | Prioritization Method Overview• The evaporating cloud: A tool for resolving workplace conflict