The cost of a Twitter-like web app development. Why it takes time and money .

So you have the idea for an awesome Twitter-like app. You go to a software house and you want the developers to estimate the time and cost of the development. Here, we are going to tell you what to expect and why.

Cost

Some people could tell you that such applications would cost you tens of millions of dollars (Twitter raised ~$20M in the Series A & B of funding rounds giving that impression) and some can say it would cost you only thousands of dollars (~$100.000). All of them are usually right. In both cases the end result would be the same. You would have the same API, the same front-end, the same look and feel and the same functionalities. The difference would however be in how it will all work ‘under the hood’. And it would be so because at the beginning you wouldn’t probably need all the infrastructure that Twitter, a very advanced web application, needs.

This is why when you start, you should start cheaper. In the first phase of development you should start with the simplest version based on a smaller number of code lines. Why? Because it’s easier to change 100.000 lines of code than tens of thousands of them. You could compare it to turning around. It’s easy when you are a human. But if you want to turn a ship around, then it’s a pretty big problem.

In our two cases the costs of development of an app depends on, first of all, the number of users. The first version of your app will probably need to sustain the load of a small number of user, let’s say, tens of thousands, whereas the more expensive one should be designed to handle tens of millions of them.

Only after have you hit those millions of patiently-awaited users you should expect the costs to raise. More users require better performance of your system and that can only be achieved by rewriting the application into smaller sub-systems, the process that results in growth of the codebase. In other words in more time invested in development.

Estimation

The development projects are usually estimated on an hourly rate because it is difficult to predict what will happen if the requirements change. If you, as a customer, would like to add a button, you will probably think it’s not a big deal. In reality, it can mean adding a thousand of lines of code. Creating a Twitter-heart takes a programmer about a day to create. If you’d like to change the functionality of the heart, it would require another day of work. It’s like with painting your porch. If you paint it white and your wife wanted it pink, you paint twice. Your cost double.

That is why it’s very important that all the requirements are gathered before the projects start. Pay close attention to what it is that you really need. The developers will be able to give you an estimated number of hours and costs ($per hour) but once you start changing the requirements, the estimation will change again.