Needed notification system for mobile investment app. Could build custom or integrate existing platform.
THE DECISION
Built custom notification system.
Existing platforms couldn't handle complex financial triggers (price alerts, limit orders)
Pricing model would cost 3x more at scale
Wanted full control over notification logic for compliance
Engineering team had bandwidth and interest
Perfect fit for use case
Long-term cost savings
Full control
4 weeks extra development
Maintenance burden
No out-of-box features like A/B testing
Custom system launched successfully. Saved ~$50K annually in vendor fees. Trade-off: Had to build analytics and A/B testing ourselves later.
Build when it's core to your product and you'll need customization. Buy when it's commodity infrastructure.