As said in my previous post, our team works in the intermediate layers of the product. I didn’t get into details, but one of the reasons why we need horizontal slices is that we have a huge job to do to improve performance of a 4-year old very technical product. The task will take several months. We have a direction to go, but we don’t know how to get there in detail. We need to iterate on it anyway, as a tunnel is the biggest risk of development. The common way of doing it is to iterate on small user stories. This is where problems begin.
First of all, user stories start with a user, and a story. We have none of these. We just have a big technical tool to implement. If we wanted to write user stories for each iteration, with a relevant title, each of them would be something like “as any user, I would like the product to be more reactive, because fast is fun”. Maybe we could suffix titles with 1, 2, …37 to make a difference between them. Some would prefer stating technical stuff like “as Johnny the developer of XYZ module, I would like more kryptonite in the temporal convector, because I need a solar field”… and would call it a user story. You see my point.
And we need a good title for a user story… sorry… a backlog item. Because it’s the entry point for the PO, the customer, the
developers, the testers,… to understand WHAT is to be done and more important, WHY it is so (which is why I prefer beginning with the why in the title). Stating how we do stuff is irrelevant, because it’s only a dev matter. It doesn’t help understanding each other in any way. Which means we don’t have any clue about how we will agree on its doneness. In other words it’s a non-sense to commit on such a story. So we have a first dead-end: we need good descriptions , but we can’t provide them in a “user story” way.
The performance project is big because the new engine, that “caches” the default one, needs to implements a lot of rules of the default engine. And releasing it is not relevant until it implement enough of these rules. Dividing the work in rules has no sense, first because we need to build the basis of the new engine, which is already a big work. Secondly because implementing a rule in the new engine is not equivalent to implementing it in the default one. The algorithms, the engines, the approaches, are different. What is natural in one environment is a lot of work in the other one, and vice-versa. In addition, the work is so huge no one can wrap his brains around the godzillions of details we need to implement. Finally, we don’t know in detail the rules implemented by the default engine. Said another way, we continuously discover what needs to be done, along the way. Even in each backlog item, we are discovering so much we can’t estimate precisely enough at the beginning, or even make sure we agree on the same thing to be done. Not to mention longer term planning (which we will see in another post). Why denying it? Discovery is our everyday reality.
So we have no user, no story, no clear short-term scope, but we agree on the fact we need small items to iterate on. But wait! Agile has the solution: spikes! We timebox a short study, which we might iterate once or twice, and we know how to go on. But that’s what we already did for 3 or 4 iterations with a team of 4 developers, we are progressing, and we still don’t know clearly what we will do in the next iteration. So spikes might sound nice, but when you are at the bottom of a technical Everest, it needs to be taken to the next level. We are not picking a logging library among 3 candidates.
So following the basic agile rules, we’re stuck. But there is a solution we’ll talk about in the next post.