I've spent the last few years building programmatic SEO systems, so I'm used to automating everything. But my father's 30-year-old hardware store in Argentina is a different beast entirely. The business is solid: regular customers, 5 employees, steady sales. But it runs on notebooks, memory, and my dad's intuition. I'm now stepping in to modernize it without breaking what works.

I've already handled the visible stuff: store layout, signage, a queue system, promo screens, better security, and physical guides for screws and bolts. The hard part is the backend. I need a system that handles:

POS with per-employee accounts
Inventory across thousands of SKUs, including unit, box, weight, and meter sales
Real-time pricing for staff
Cash reconciliation and bank transfer matching
Purchase orders and supplier management
Margins by product and category
Low-stock alerts and dead inventory tracking
Employee productivity metrics
Ecommerce and nationwide shipping
Multi-location shared inventory and a central dashboard

The catch: my dad is brilliant at hardware but allergic to computers. If selling 10 screws takes 15 screens, the staff will revert to paper. i also don't want to drop money on a heavy ERP and force a big bang change without solid processes first.

my long-term goal is a second location with everything connected, plus ecommerce as a real revenue stream. But I know that's premature until the core data is clean.

For anyone who's modernized an old family retail business, especially with large SKU counts:

What's the first thing you'd tackle?
What does a realistic 3/6/12-month roadmap look like?
What absolutely must be fixed before ecommerce or a second store?
Which processes gave you the biggest ROI when automated?
How do you keep inventory accurate with thousands of small items?
What KPIs should I start tracking today?
And what mistakes should I avoid?

I'm not looking for a software recommendation. I want to understand how people structured the transition itself. If you've been through this, I'd love to hear what worked, what didn't, and what you'd do differently