The Design Process

When I was working at Infraware, I designed a small framework to solve a problem. I then implemented my solution using that framework. But in reality it wasn't that simple. It would be nice if we could design a tool or server or protocol and get it right the first time. But even for an experienced architect this is unlikely to happen.

The trouble is that each problem is different. The only way to learn about the problem you are working on is to, well, work on it. This means the first version will probably be a mess. The second version might be a little better, and then the third, and so on. But the most important part of the design will actually be the mistakes you make and the feedback you get.

The first version of my framework was extremely simple. In fact, it was hardly a framework at all. As I used the framework, I learned of little problems. Often I could get around those problems, but the solution was ugly. The real solution, I found out, was to change the framework itself. I went through this process a number of times. I would run into a limitation or a flaw of the framework, and eventually I would have to fix the problem. This is where the real learning occurred. It wasn't the design and implementation of the framework, but the uncovering of problems that allowed me to gain a deeper understanding of the framework and make it better.

However, the best way to learn about your design is to let other people use your tool. You are only one person. You can't foresee every possible way in which your tool will be used. By getting feedback directly from many people, your insights will be far greater. Some users may even make design suggestions. The iterative process of design, implement, discover faults, repeat is instrumental to a successful project. It is unfortunate that so much code is never used. The architect will never learn from his mistakes. In many circumstances, the feedback goes to a different person or it may not come until years after the initial design.

The last version of the framework before I left still had some issues. But I chose not to try and correct these problems because it just didn't make sense under the circumstances. Sometimes it just won't be worth your time. In other cases, there may be design tradeoffs. You will have to chose what your design will support and what it won't support. The more powerful and abstract the tool, the harder it will be to implement. It will also be harder to learn how to use it. Sometimes a special purpose design or a tool with limited functionality will be better (and faster).

Developing an end-user application is difficult. But the person who builds the tools and APIs that allow for the development of those applications has a far greater challenge. He must conceive of entire classes of applications that will be built using his software. He will have to make difficult decisions about what will be possible. His decisions will effect the design and implementation of thousands of applications. It may even alter or dictate how future programmers think and solve problems. So go forth and start making mistakes now. The sooner you get it wrong will be the beginnings of getting it right. And that may be the birth of a project that spawns a million other projects.


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