AI Coding · Add features to an existing system

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This walkthrough uses a sales CRM: it lacks a "customer follow-up reminder" feature, so overdue customers go unattended. In Qoder, you hand the existing code to qwen3.7-max and, with one sentence, ask it to incrementally add the reminder without touching old features such as search and filtering. Tool: Qoder · qwen3.7-max reads the existing code → incremental development.

Actual output

Same existing codebase, only one feature instruction added. Before and after adding the feature (both are clickable to try):

Basic CRM before adding the feature

Click to try

After adding the follow-up reminder

Click to try

Steps: Add a feature with one sentence

In Qoder, send the existing code along with the instruction below to qwen3.7-max:

This is my existing CRM system code (see below). Please add a "customer follow-up reminder"
feature without modifying the existing features (search, status filtering):
1. Customers not followed up for more than 7 days should be highlighted in red and pinned
   to the top (closed and lost customers are excluded from reminders);
2. Display a statistics bar at the top of the page: "Follow-up reminders: N customers
   not followed up for more than 7 days";
3. Add a "Days since last follow-up" column that shows the number of days, with reminder
   customers highlighted in red bold;
Keep the existing code style and output the complete modified file.
[Existing code] {paste file content}

Notes

Consumption: This playbook involves a single round of incremental development (within the Qoder tool, requires reading the full existing code). Consumption in brownfield development is positively correlated with codebase size — the existing code must enter the context, and larger code means higher single-round input.
Consistency: The feature passed on the first try: overdue items correctly pinned and highlighted in red, closed and lost customers correctly excluded, and exactly 7 days did not trigger a false alarm.

​Actual output

​Steps: Add a feature with one sentence

​Notes

Actual output

Steps: Add a feature with one sentence

Notes