Lean UX/UI

Lean UX is a technique that you must use if you are both working with a lean mindset and using agile development methodologies. Its support for agile and easy integration into the design thinking approach makes it a very useful technique.

What is lean in short?

very product is created to solve a problem or fulfill a need, but do they really? Every feature added is believed to be useful and needed by the users, but who are these users really? You need to validate or, sometimes, invalidate your assumptions every step of the way. In the end, everybody wants to create a product people will actually buy and use, but making sure that is what they end up with requires an iterative approach. This is what lean is. To learn more about the lean mindset and the lean startup approach, I strongly suggest reading Eric Ries’ “The Lean Startup” book.

A quote from Eric Ries to point out the core of the lean approach.
"Build-Measure-Learn feedback loop is at the core of the Lean Startup model."

What is Lean UX/UI?

UX and UI are an inseparable part of the product development process. However, you cannot apply your UX research, design a sleek interface, and hand over your UI under the assumption that it is perfect and complete. More often than not, you will come to realize a great deal of what you thought was right for the product or the user, isn’t. This is where lean UX comes in. Using agile development, rapid changes are implemented throughout iterative cycles and the data that is gathered along the way is fed back into the loop to create UIs that offer a better experience.

Especially when it comes to the lean approach and agile methodologies, you can not apply UX studies & define user experience then design a sleek interface and hand over your perfect files to development team. Because you will and should “learn” on the way, not after launching your product or service by spending so much effort. That is why Lean UX follows rapid changes and iterative cycles as agile development and use the data gained to create better experiences and better UI.

How Lean UX Works? Assumptions & Hypothesis

Your hypothesis is your basis in lean UX/UI. You need to create hypotheses in order to start researching and begin designing a good experience. In order to create hypotheses, you should list out your assumptions. In the beginning of a project, the entire team must be involved in coming up with these assumptions. This helps build a common understanding amongst the team as a whole. With these assumptions in place, the benefit hypothesis can be built. So what is a benefit hypothesis?

Benefit hypothesis: Measurable value your product or service would offer

The first UX and UI practices are studied using these hypotheses. In lean UX, the focus is mostly on the hypothesis and finding the best possible way to validate them rather than producing final deliverables. Since the whole team including the UX/UI designers are working collaboratively, they create new assumptions followed by a new benefit hypothesis based on data generated in the previous round. As can be seen in the figure below this process is a continuous, iterative cycle.

In this assumption creation process, you seek answers for the following questions:

  • What is the problem and what is the solution for that problem?
  • Whose problem is this? Who would use this product or service?
  • When and where would they need this solution?
  • What are the pain points during the customer journey?
  • Some other questions may be added to this list and some questions may have more than one answer. As the list grows, so to does the uncertainty in the assumptions which means you need to validate your assumptions quickly to avoid wasting time and effort. In order to do so, you need to come up with hypotheses.

    Many companies run A/B tests mostly to validate their assumptions using the hypotheses they formulated. For example, if they are unsure where to place a call to action button, they create two or more hypotheses and present them to actual users.
    You need to collect data from your actual users in their own journeys to have consistent and correct values.

    This process composes an iterative cycle. In the lean mindset “you know nothing”, are trying to learn from your users, and therefore must reconsider your UX each step of the way, always keeping the big picture in mind.

    What about User Interface?

    There’s no way to design the ultimate one-size-fits-all user interface. However, knowing that the lean approach is being used, designers can create more adaptable alternatives that can easily be modified with each iteration. As a designer, I myself know the difference. To differentiate valid decisions from assumptions design teams should be involved every step of the way. Change has always been an essential part of the design process. It’s just become more rapid lately with lean and agile approaches.


    The ultimate goal is to create products or provide services people - who suffer from the problem being solved - would actually buy and use easily. You want your solution to integrate into people’s lives so you should keep asking, changing, and adapting. Only by going through this cycle can you design products/services that are both useful and usable.

    “The only way to win is to learn faster than anyone else.”
    Eric Ries

    “Here is the worst possible way for you to try to figure out if your idea solves somebody’s problem: Ask them. The vast majority of entrepreneurs seem to think that explaining their concept in detail to a few people and then asking whether it’s a good idea constitutes validation. It does not.”
    Laura Klein

    Important Links

    Link to “The Lean Startup” book on Amazon:
    Link to the author’s profile in Linkedin: Eric Ries
    Link to “The Lean UX” book on Amazon:
    Links to the authors’ profiles in Linkedin: Jeff Gothelf & Josh Seiden.
    ( https://www.linkedin.com/in/gothelf/ & https://www.linkedin.com/in/jseiden/ ) Link to “UX for Lean Startups” book on Amazon:
    Link to the author’s profile in Linkedin: Laura Klein