Build vs buy: SaaS or custom software?

• Buy (SaaS) when the need is common — email, accounting, CRM, chat. It's faster, cheaper and maintained for you
• Build when the process is your competitive advantage, off-the-shelf tools force painful workarounds, or many tools need tying together
• Hybrid: buy the standard parts and build the glue — integrations, automations and a custom app for the unique workflow

Example: a custom ERP that connects to Zoho Books for accounting instead of rebuilding accounting.