Sales Revenue Dashboard

I’m looking for an experienced data analyst / BI specialist to build an interactive sales and revenue dashboard from my existing CSV sales data.

The CSV currently contains:
- Transaction date
- Earning amount
- Product name
- Product ID
- Country
- Sales platform

What I want to achieve:
I want a clean, high-level dashboard that allows me to quickly understand how the business is performing, what is driving revenue, what is changing over time, and where there are opportunities or problems.

The dashboard should include, at minimum:
Core KPIs
- Total revenue
- Revenue growth / change vs previous period
- Number of sales / transactions
- Average revenue per sale
- Number of active products
- Top product revenue
- Revenue concentration / share from top products

Revenue analysis
- Revenue over time
- Revenue by product
- Revenue by platform
- Revenue by country
- Product growth / decline
- Platform growth / decline
- Country growth / decline

Deeper analysis
- Product × platform performance
- Product × country performance
- Revenue share by product, platform and country
- Product ranking by revenue and growth
- Identification of major revenue increases/decreases and trends

Interactivity
I would like the dashboard to have global filters for:
- Date / date range
- Product
- Platform
- Country

The different KPIs, charts and tables should update based on the selected filters.
I also want the ability to change the time granularity where appropriate (daily, weekly, monthly, quarterly, yearly).

Platform / technology
I am not fixed on the BI platform or technology.
I would like recommendations for the best solution based on my requirements and explain why.

I am looking for a fully local/self hosted/offline solution. Something that is easy to use. Ideally free or open sourced.

Please include in your proposal:
1. Which platform you recommend
2. Why you recommend it
3. Any ongoing software costs
4. How the CSV data would be imported and refreshed
5. How easy it will be for me to add new CSV data in the future
6. Whether the solution can later scale to additional data sources

Deliverable
A polished, easy-to-use dashboard that I can use regularly to monitor and analyze sales performance.

I am looking for someone who can think about the analytics and recommend improvements, rather than simply build a dashboard, and a long term data analysist specialist that I can refer to.

If you see additional KPIs, visualizations, or analytical views that would provide meaningful business insight from this dataset, please recommend them. Thanks!