Plaid Sandbox to Production Checklist: What to Validate Before Launch

Introduction

The jump from Sandbox to Production is where a lot of Plaid integrations “almost work” and then quietly break in the real world.

In Sandbox, everything is predictable: test institutions behave nicely, data looks clean, and error rates are low. In Production, users revoke permissions, bank connections expire, webhooks arrive out of order, and support tickets show up the moment your first cohort hits payroll day.

That’s why teams who ship reliably don’t just “go live”—they follow a plaid sandbox to production checklist that validates the exact failure points that only appear with real users and real banks.

This guide is written for global fintech teams (even if Plaid is strongest in the US/Canada) and for anyone working with a fintech software development company or in-house engineering team doing plaid integration. We’ll cover what to validate before launch—Link, tokens, webhooks, data quality, security, monitoring, and operational readiness—so your launch feels boring (in the best way).

The Reality Check: Sandbox vs Production Isn’t Just “Different Data”

Plaid’s Sandbox is built for development and uses test data, while Production uses real bank connections and real user behavior. That gap is exactly why a checklist matters.

The Plaid Sandbox to Production Checklist (What to Validate Before Launch)

1) Production Access + App Configuration

Before anything else:

• Confirm Production access is approved and your Production keys/secrets are set up correctly.

• Ensure your app’s use case description / Link customization is configured as required in the Dashboard for your region and setup.

• Double-check you’re not accidentally calling Sandbox endpoints in Production (it happens more than teams admit). 

2) Link UX: Make Sure Real Users Don’t Get Stuck

Link is where your conversion either happens—or dies.

Validate:

• Create Link tokens properly and confirm they’re short-lived, one-time use, and generated per session.

• Handle update mode (re-auth / reconnect flows) for when an Item needs attention.

• Test multiple user paths: first-time link, relink, switching accounts, backing out mid-flow.

What to look for:

• Are error messages helpful or scary?

• Do users know what’s happening when they’re asked to re-auth?

• Can they retry cleanly without creating duplicate Items?

3) Token + Item Lifecycle: The “Invisible” Bugs

Plaid integrations often fail because teams treat tokens like static credentials.

Validate:

• Your flow from public_token → access_token is correct and stored securely.

• You have a user-friendly “disconnect” flow (and you actually revoke/stop using tokens when needed).

• You can handle Items that move into an error state, require update mode, or have permissions revoked.

Plaid explicitly notes that if a user revokes permissions, attempts to use related tokens can fail-so you must listen to the right webhooks and stop using those credentials.

Learn More

4) Webhooks: Treat Them Like Your Source of Truth

Webhooks are not “nice-to-have”—they’re how your product stays accurate without constant polling.

Validate:

• Your webhook endpoint is reachable, returns valid responses, and is stable under load.

• You correctly process webhook events for Items, Transactions, Auth, etc.

• You can safely handle duplicates, retries, and out-of-order delivery (it will happen).

Plaid uses webhooks to notify you about Item changes and async process completion.

Must-have engineering behavior:

• Idempotency: the same webhook event processed twice should not create duplicate records.

• Dead-lettering / reprocessing: if a webhook fails, you can replay it safely.

5) Transaction Data: Accuracy, Freshness, and “Sync Reality”

If your product relies on Transactions, the biggest production pain is users expecting bank data to be “live,” when it’s actually sync-based.

Validate:

• Your “data freshness” messaging is honest.

• You handle pending vs posted transactions (and don’t double count).

• You have a reconciliation strategy when users say “my balance doesn’t match my bank.”

This isn’t just product polish—it reduces refunds, disputes, and support load.

6) Error Handling: Use Plaid Error Codes the Right Way

In the Plaid API, application-level errors are surfaced in response bodies with error_type and error_code—and you should use those (not just HTTP codes) to decide what to do next.

Validate:

• Retry logic only for retryable errors.

• Clear user prompts for “action required” errors (like re-auth).

• Internal alerts for repeated institution issues.

7) Security + Compliance Hygiene Before Launch

This is where a global fintech mindset matters.

Validate:

• Secrets are environment-scoped and not shared casually across Sandbox/Production.

• Access to Production keys is restricted (least privilege).

• Logs don’t store sensitive personal data.

• You have audit trails for who changed what.

Plaid has distinct environment secrets (Sandbox/Development/Production) specifically to support safer access separation.

8) Monitoring, Alerts, and “Day-2 Operations”

A production launch is not a finish line—it’s when the work gets real.

Validate you have:

• Dashboards for Link conversion, webhook failures, Item error rates

• Alerts for spikes in failure rates (often institution-specific)

• Replay tooling for failed jobs/webhooks

• A simple “health” view your team checks daily

Plaid’s own Launch checklist exists because robustness is mostly about pre-production readiness steps like these.

9) Go-Live Runbook: The 60-Minute Reality Drill

Before launch, do a short “war game”:

• What happens if webhooks stop for 30 minutes?

• What happens if one institution has elevated errors?

• What happens if a user revokes permissions and then tries to fund an account?

If your team can answer those calmly, you’re ready.

Where FintegrationFS Helps (Without the Guesswork)

As a global fintech software development company, FintegrationFS supports teams shipping reliable fintech software development services—including end-to-end plaid integration for Fintech app Development and broader Digital Banking Software Development.

FAQs 

1) Why does my Plaid integration work in Sandbox but fail in Production?

Because Sandbox is controlled and predictable, while Production includes real bank behavior—re-auth events, revoked permissions, intermittent connectivity, and real-world error patterns.

2) What’s the #1 thing teams forget before going live?

Webhooks. Teams often “poll” in Sandbox and forget that in Production, webhooks are what keep statuses accurate and workflows reliable.

3) Do I really need reconnect/update mode flows?

Yes. Users will lose connections, banks will require re-auth, and permissions can be revoked. If you don’t support update flows, your product silently degrades over time.

4) What should we log (and what should we never log)?

Log event IDs, timestamps, error codes, and workflow state transitions. Avoid logging sensitive personal data or full payloads that contain confidential details—especially in Production.

5) How do we reduce support tickets after launch?

Be proactive: clear user messaging, strong error handling based on Plaid error codes, and monitoring that catches issues before users report them.

6) What’s a realistic “minimum production-ready” checklist?

At minimum: Production keys configured, Link UX validated, webhook processing stable + idempotent, Item lifecycle and permission revocation handled, errors mapped to user actions, and basic monitoring + alerts in place.