What is iterative development?

Iterative development is an approach to building a software product where the system is developed not all at once, but in stages, through repeating cycles (iterations). Each iteration is a mini-project that includes analysis, design, development, testing, and gathering feedback.

The main idea: build, verify, and improve the product step by step, instead of waiting until it is fully ready.

---

#How it works

1. The team defines the main requirements and splits the project into parts.
2. The first set of features is taken - for the first iteration.
3. Over a few weeks, a working version of the product is built (even if simplified).
4. The version is tested and shown to the customer.
5. Based on the feedback, decisions are made - what to change, what to add, what to drop.
6. The next iteration starts - with refinements and new features.

The cycle repeats like this until the product reaches the needed quality and completeness.

---

#Key features

• Continuous improvement. Each cycle increases the product's value.
• Feedback is built into the process. Errors and misunderstandings are caught early.
• Priority for what matters. The team implements the most needed features first.
• Flexibility. If requirements change, they can be adjusted already in the next iteration.
• A working result at every stage. After every iteration there is a product that can be demonstrated.

---

#Example

Imagine you need to build a mobile app for food delivery.

• Iteration 1: authorization and menu browsing.
• Iteration 2: placing an order and payment.
• Iteration 3: courier tracking.
• Iteration 4: reviews, promotions, personalization.

After each iteration: testing, feedback analysis, improvements. This way the app "grows" while staying functional from the very start.

---

#Difference from the waterfall model

In Waterfall everything is done sequentially: first the whole thing is designed, then the whole thing is built. In the iterative model the process is cyclical - each iteration includes the full set of stages, but at a smaller scale. This makes it possible to see the result earlier and adapt faster to changes.

---

#Conclusion

Iterative development is a way of building a product through constant repetition and improvement. It reduces risks, speeds up getting feedback, and makes the result as close as possible to what the user actually needs.