How Phantm Turned Strategy into Action with the Decision Stack

How a simple visual model can unblock strategic execution

Most companies don't need a new strategy—they need help clarifying the one they have. As a product leader who specialises in bridging strategy and execution, I've found the Decision Stack isn't just another framework. It's a catalyst for action.

Starting from the middle

The magic happens in the middle. While others use the Decision Stack top-down or bottom-up, I use it to create motion from the centre, in what I call a “middle-out” manoeuvre. Here’s how it works.

From the middle to the left

A few focused 45-minute sessions with executives to wrangle their thinking—coherent or not—into a single expression of strategy. This isn't about comprehensive documentation, it's about clarity of direction. Pointed questions quickly cut through strategic fluff:

• "Sounds great. Which goal does this serve?"
• "Can you sum that up in terms of our mission?"
• "How will we measure this against our objective?"
• “Do we have any options to create outcomes toward this lonely objective?”

Middle to the right

Engage teams with clear priorities. Firstly, this is about alignment, and The Decision Stack is a forcing function for focus. Teams either discover they're working on things that don't matter, or they gain a fuller understanding of 'why' their work matters. In both cases, the work improves. Second, it’s a catalyst for the action that kick-starts a virtuous cycle where customer learning informs strategy. It's not about involving everyone in everything—it's about the right people doing the right things to realise the most important goals. And in case it’s unclear, getting started is the most important thing!

Learning your way forward

Consider Phantm, a seed-stage startup with a mission for a plastic-free planet. Their Decision Stack illustrates how strategy evolves through execution:

At first, the company bet too big on a single digital initiative, with limited opportunity to test and learn with customers. Just like 90% of ideas, this initiative fell short of meaningful customer outcomes, leaving the company with an impossibly short runway to reinvent itself and find the right solution for customers, along with an investible proposition for its backers. The time for postulation had ended, and decisive action was the only way forward. Using the Decision Stack, Phantm reframed their mission and clarified immediate priorities in just a few 45-minute sessions over a couple of weeks.

From Clarity to Action: The Phantm Story

What happened next demonstrates the power of clear strategy paired with rapid execution. Within 6-8 weeks of setting new direction, the team: confirmed the problem; busted various assumptions with rapid testing; iterated multiple viable solutions; took the learning into a primitive software prototype for customer demos; won Letters of Intent from 40% of customers attending a product demo (4 of 10), and; closed a bridge round to extend runway for a solid Series A fund raise.

Speed requires focus, and that starts with the clarity that comes from The Decision Stack.

• A few days to get enough definition and alignment to drive first action
• A few hours to get from the first expression of strategy to a testable prototype
• Only weeks to de-risk the technology platform with a data engineering Proof of Concept
• Just six days to design and build primitive working software for live demos
• A month of customer engagement, with live demos to customer executives—and countless other experiments—in a virtuous cycle of learning and strategic iteration
• A few weeks to refine a winning proposition with an investible strategy that helped win further investment

We needed a jolt, not a gentle transition. The Decision Stack was our catalyst and remains the backbone of our strategy today. With it, Jonny brought the experience and energy to move us forward—at a speed we hadn't seen before. In just two months we had a new product strategy, a viable technology pathway, and a team delivering outcomes at pace.

—Elliot Costello, CEO, Phantm

The Beauty of Simplicity

The power of the Decision Stack isn't in being comprehensive—it's in being clear. While the top half (vision, strategy, objectives) typically remains stable over months or years, the bottom half (objectives, metrics, initiatives) evolves rapidly through learning and execution.

This isn't oversimplification. It's about distilling complexity into actionable clarity. Teams still go deep in ways that suit them best, but the Decision Stack becomes the one artefact that consistently motivates aligned action.

The Investor Dimension

The Decision Stack's clarity and simplicity make it equally valuable in investor communications. Here, the middle-out manoeuvre extends upward to capital partners.

Effective investor conversations require a delicate balance. Diving straight into product features risks appearing tactical without strategic grounding. Conversely, remaining in the strategic stratosphere can seem disconnected from execution reality. The Decision Stack bridges this gap.

As an expression of company purpose, future vision, and key objectives, the strategic discussion can be concise. This sets the stage for the real conversation: how you're learning from customers, de-risking the strategy, and letting those insights inform decisions and further investment.

The Phantm case illustrates this perfectly. Their investor discussions demonstrated:

• Clear strategic intent through the Decision Stack
• Rapid customer learning cycles that informed strategy
• Evidence-based pivots that showed maturity and adaptability
• Deep (yet fast) investigation of risk areas that matter most

This combination of strategic clarity and efficient execution focussed on addressing key risks creates investor confidence. It makes the capital allocation decision more straightforward—investors can clearly see how their funds will accelerate a well-considered strategy that's already showing signs of success.

Making it work

Success with the Decision Stack isn't about rigidly following a framework. It's about understanding how to use it as a lever for change. Here's what I've learned works:

1. Stay lightweight
   The best Decision Stack sessions often happen in the moment, not in scheduled workshops. I'll typically spend less than an hour sketching out a stack based on available information and educated guesses ahead of time. The framework itself rarely leads the conversation—instead, it appears at that crucial moment when strategic discussions start circling. You know the one: where each contributor repeats their position without gaining additional clarity. A rough Decision Stack introduced at this point often breaks the cycle, channelling confusion into clarity.
2. Focus on clarity
   Like a sticky-note or index card, the Decision Stack's confined space forces brevity. After writing strategy a hundred ways to Sunday, I've learned that more words rarely equal more clarity. Think of it like making consommé—it's what you filter out, not what you add, that brings crystal clarity. The Stack's boundaries naturally impose this refinement process.
3. Prioritise evolution
   Stop talking, start working. There's freedom in letting go of proving yourself right—because you won't be, no matter how hard you try. The Decision Stack acknowledges this uncertainty by design. What you're aiming for is just enough detail to enable action toward an outcome, at a speed that delivers insight more efficiently than further analysis, while maintaining flexibility to integrate new learning. Expect to be wrong. Finding out how you're wrong quickly is much more valuable than finding out you're not right, slowly.
4. Show the thinking
   Let customer learning visibly inform your decisions. When teams see how real-world feedback shapes strategy, they're more likely to engage at their full potential, and contribute to evolution that leads to the win. This creates a virtuous cycle where clarity drives action, action generates learning, and learning refines strategy.

The result? A lightweight tool and a set of movements that catalyses action while maintaining strategic alignment. As Phantm demonstrates, when you combine clear direction with rapid learning cycles, you can achieve in weeks what might otherwise take months or years—while at the same time engaging everyone on the journey.