integration cost
Integration and Developer Cost: Build vs Buy
Engineering weeks per vendor, build-vs-buy economics, and the ongoing maintenance line nobody costs in the original quote.
2-4w
Stripe hosted Checkout
4-8w
Stripe Elements + API
6-12w
Adyen direct integration
3-6mo
Custom processor / IC+
Headline answer
A clean Stripe Checkout integration takes 2-4 engineering weeks for a typical SaaS. A self-hosted Stripe Elements + Payment Intents server flow with SCA / 3DS handling is 4-8 weeks. An Adyen direct-API integration is 6-12 weeks because of the certified-integrator process and the wider acquirer-level optimisation work. Ongoing maintenance runs 1-3 engineering days per month for SDK upgrades, dispute handling, refund tooling, webhook reliability, and reconciliation.
The typical integration timeline
01Vendor sign-up
→02Test mode
→03Checkout flow
→04Webhooks
→05SCA / 3DS
→06Refunds + disputes
→07Reconciliation
→08Go-live
Engineering weeks by vendor (illustrative)
(illustrative example, not a real company)
Stripe Checkout
Sign-up + sandbox
0.5w
Checkout integration
1.0w
Webhooks + reconciliation
0.5-1.5w
Go-live + edge cases
0.5w
Total
2-4 weeks
Stripe Elements custom
Sign-up + sandbox
0.5w
Elements UI + Payment Intents
2-3w
SCA / 3DS + tax
1-2w
Webhooks + reconciliation
1-2w
Total
4-8 weeks
Adyen direct API
Account + certifications
2-4w
Drop-in / Components integration
2-4w
Acquirer-level optimisation
1-3w
Go-live + monitoring
1-2w
Total
6-12 weeks
Build vs buy
- Buy (hosted Checkout) when: small team, no payments engineer, simple SaaS pricing, ecommerce on Shopify/WooCommerce.
- Hybrid (Elements + custom flow) when: you need branded checkout UX but do not want to handle SAQ-D PCI scope.
- Build (direct API + own UI) when: marketplace splits, multi-acquirer routing, custom dunning, or you need to optimise authorisation rate at the issuer level.
Ongoing maintenance cost
- SDK upgrades: monthly for Stripe (rapid release cadence), quarterly for Adyen and Braintree.
- SCA / 3DS rule changes: 1-2 engineering days per year on EU/UK exposure.
- Dispute and refund tooling: ongoing, scales with dispute rate.
- Webhook reliability: idempotency, retries, dead-letter handling. Expect 2-5 days/quarter on hardening.
- Reconciliation engineering: monthly review of vendor reports vs internal ledger; can become a part-time job at $5M+/yr GMV.
Related
verified Last verified June 2026