CSS to Sass

Product Design Sprint Process

Google Ventures' design team started Product Design Sprint, which is a 5-phase exercise (now 6-phase) with the goal to arrive with a validated solution before jumping to an expensive build.

The sprints are a good starting point when starting a new product idea, product workflow or feature. It also works well in solving problems with the existing product.

Product design sprints are test-driven design.

A Product Design Sprint is a technique to quickly design, prototype, and test the viability of an idea, product, or feature. The design sprint consists of 5 phases (typically days), starting with design thinking and ending with a user-tested prototype.

product design sprint

Five Phases of Product Design Sprint

Phase 1

Day ONE for the Product Design Sprint is about gathering all existing information/knowledge about the idea, the product or the feature requests and the problems circling behind those requests in order to properly formulate our assumptions. This stage would help us understand the riskiest knowledge gaps and validate or invalidate our riskiest assumptions.


The goal to is develop a common understanding of the working context including the problem, the business, the customer, the value proposition, and how success is measured.

At the end of this phase, we also aim to identify some of our biggest risks and started to make plans on how to reduce them.


  • Define the Problem
  • Define the Customer / User
  • Define the Business Opportunity
  • Define the Value Proposition (Why would someone use/pay for this product or feature?)
  • Define the use-cases or a rough description on the process flow (from the user perspective)
  • Gather relevant User Research from user interviews
  • Gather examples of other people/products solving similar problems
  • Produce a Competitive analysis on similar products


  • Notes & Documentation - Summary on the definitions and goals discussed. This would serve as a reference on what needs to be done.
  • A plan on what to do on the next phase.

Phase 2

Day TWO for the Product Design Sprint is all about exploring potential solutions that meet the users' needs, requests or requirements. The team must have insightful solutions based from different perspectives in order to decide which approach best solves the problem (Take into consideration the time, budget, technical capacity, etc.).

This phase is also where we start eliminating as many of these options as possible.


Generate many insights and potential solutions, options and alternatives to our customer’s problems.

At the end of this phase, we want to be more confident on the solutions we choose because we have explored so many alternatives prior to our decision.


  • Constantly ask “How might we?” to uncover more insights on the many alternatives at hand
  • Generate, develop, and communicate new ideas.
  • Low-fidelity sketches, paper sketches


  • Critical Path Diagram - highlights the story most critical to the challenge at hand. Where does your customer start, where should they end up and what needs to happen along the way?
  • Define Prototype Goals - What is it we want to learn more about? What assumptions do we need to address?

Phase 3

Day THREE for the Product Design Sprint is all about eliminating the unfeasible alternative solutions and arrive at the conclusion on the best solution. This will be the guide or the reference for the prototype we will produce in Phase 4.

This phase would also be worthwhile if we can gather insights from the cuctomer-facing team (i.e. sales, support) and technical perspective from the development team in order to guide us on deciding the best solution to implement that answers our business goals at the same time, fits in our technology stack making it sure we don't stumble upon miscommunication, uncertainty and challenges.


The goal is decide on the best solution to take that is already validated, free from uncertainties and technical challenges.


  • Storyboard the core customer flow. This could be a work flow or the story (from the customer’s perspective) of how they engage with, learn about and become motivated to purchase or utilize a product or service.


  • The Prototype Storyboard - a comic book-style story of your customer moving through the previously-defined critical path. The storyboard is the blueprint for the prototype that will be created in phase 4.

Phase 4

Day FOUR for the Product Design Sprint is all about producing a prototype. A prototype is a very low cost way of gaining valuable insights about what the product or feature needs to be. During this stage, we would know what works or not so we will be confident that we invest on the right solution for more permanent implementation for product development.


Build a prototype that can we can test to our existing or potential customers.


  • Front-end Development to implement prototype in HTML/CSS


  • Interactive Prototype
  • A plan for testing. If we are testing workflows, we should also have a list of outcomes we can ask our testers to achieve with our prototype.

Phase 5

Day FIVE for the Product Design Sprint is all about testing the prototype we produced on Phase 4 with existing or potential customers.


Test the prototype.


  • Observe and interview customers as they interact with the prototype.
  • List down what were the red routes (critical activities that users will perform) on the prototype.


  • Summary/report of our learnings from testing the prototype.
  • A full-specification and scope on the product/feature requirements that will be implemented beyond the design sprint.
Most people make the mistake of thinking design is what it looks like. People think it's this veneer — that the designers are handed this box and told, 'Make it look good!' That's not what we think design is. It's not just what it looks like and feels like. Design is how it works. Steve Jobs