Startups (pre-PMF to Series A) optimize for two things software-wise: speed to ship + low fixed cost.
The trap: is over-investing in enterprise tools (Salesforce, Workday, NetSuite) too early when free + freemium tiers cover 80% of the need. The pre-seed / seed startup stack: HubSpot Starter or Pipedrive (CRM), Loops or Customer.io (email), PostHog free tier or Mixpanel free (analytics), Linear (project mgmt), Vercel + Supabase or Railway (hosting + DB), QuickBooks Online or Xero (accounting), Mercury or Brex (banking + cards), Rippling or Gusto or Deel (payroll + HRIS). Total monthly software spend pre-PMF: $200-500. Series A+ adds: Stripe Billing + Maxio for subscriptions, dedicated DPA/security tools (Vanta, Drata), proper CDP (Segment, RudderStack). The single biggest leverage: pick tools your future $10M-ARR self will still use. Migration costs at $5M ARR are brutal.