Payment Gateway Integration by Alpha Expansion
Payment Gateway Integration01Card data isolated02Webhooks verified03Settlements reconciledBook a call

Payment Gateway Integration

PAYMENTSCUSTOMERSCAN TRUST

We integrate payment gateways into web and mobile applications, so customers can pay by card, wallet or local method and every payment, refund and settlement is recorded correctly in your system.

Card data isolatedWebhooks verifiedSettlements reconciled

Card data isolatedWebhooks verifiedSettlements reconciled

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01Our Approach

A payment is finished only when your system, the gateway and the bank all agree that the money moved, and not before.

02Overview

Payments built into your web or mobile product

  • 01Card data isolated
  • 02Webhooks verified
  • 03Settlements reconciled

Payment gateway integration connects your application to the provider that processes its payments. We implement the checkout, whether the provider's hosted page, embedded card fields or a mobile SDK, and the server side that creates payments, confirms them through verified webhooks, issues refunds and reconciles settlements. The provider is yours to choose, and the merchant account is held by your business, not by us.

It suits products taking payment for the first time, adding a second provider or entering a market with its own methods. Gulf projects, for example, usually need local debit schemes such as mada in Saudi Arabia or KNET in Kuwait beside international cards and wallets, reached through a provider licensed to offer them. We work from each provider's published documentation and test accounts.

Talk to us about your project
03What We Do

Capabilities, End to End

01
Order and payment mapping

Your orders, invoices or bookings are mapped to the gateway's payment objects, with amounts, currency, customer reference and metadata carried so each payment is traceable.

02
Flow of status

Your application asks for a payment and the gateway decides its outcome. Status travels from gateway to application only, through webhooks and verified lookups, never from the browser.

03
Keys and card scope

Secret keys stay on the server in a secrets store, and card details go directly from the customer's device to the gateway, keeping your systems outside most card security requirements.

04
Unresolved payment queue

A payment whose result is unknown, perhaps because the customer closed the window during authentication, is queued and checked with the gateway until it resolves.

05
Idempotent requests

Every charge and refund request carries a unique key, so a timeout followed by a retry cannot bill the customer twice or refund the same amount again.

06
Payment monitoring

Success rate by method, declines, webhook delays and unreconciled settlements are tracked, and a sudden fall in approvals raises an alert to the team.

04In Production

What It Looks Like When It Ships

app.novapay.io/overview
Live
Nova Pay
Accounts / Overview
Search...
⌘K
MC
WORKSPACE
Accounts
Payments
Cards
Invoices
MORE
Reports
Team
Settings
Usage
72% of plan
Team & permissions
12 members
Invite member
Member
Role
Last active
2FA
MC
Maya Chen
maya@acme.com
Owner ▾
Just now
OH
Omar Haddad
omar@acme.com
Admin ▾
12m ago
AC
Ana Costa
ana@acme.com
Editor ▾
2h ago
LP
Liam Park
liam@acme.com
Viewer ▾
Yesterday
Audit log
Payout scheduled - $18,400
6m ago
Card approved - A. Rivera
22m ago
Statement generated - Sep
2h ago
Card data isolated
Webhooks verified
Settlements reconciled
Payment timelineMethod performancePending queueSettlement match
05What You Receive

Handed Over, Ready to Run

SCROLL
01
Checkout for web and mobile
02
Server-side payment service
03
Verified webhook handling
04
Refund and partial refund flows
05
Saved payment methods option
06
Settlement reconciliation report
07
Test cases from sandbox
08
Source code and documentation
06How It Runs

From Kickoff to Launch

01
Choose and scope
02
Build the flows
03
Test the failures
04
Go live gradually
01
Choose and scope

Together we compare providers against your markets, methods, currencies and pricing model, confirm what your merchant agreement includes and decide between hosted, embedded and direct integration.

02
Build the flows

Checkout, customer authentication, webhooks, refunds and saved cards are implemented against the provider's sandbox, with each of your order states mapped to a payment outcome it can reach.

03
Test the failures

Declines, abandoned authentication, duplicate clicks, lost connections, delayed webhooks and disputed payments are all simulated before launch, since most production problems come from these paths and not from the successful one.

04
Go live gradually

After the provider's own checks, live payments open to a small share of customers. Approval rates and reconciliation are verified before everyone else is moved across.

07Technology

The Stack We Use

CheckoutHosted payment pagesEmbedded card fieldsApple Pay and Google PayMobile payment SDKsSecurityTokenization3-D SecureSecrets managementPCI DSS scopingCheckoutHosted payment pagesEmbedded card fieldsApple Pay and Google PayMobile payment SDKsSecurityTokenization3-D SecureSecrets managementPCI DSS scoping
ServerNode.jsTypeScriptPostgreSQLWebhook verificationFinanceSettlement filesReconciliation jobsRefund controlsDispute trackingServerNode.jsTypeScriptPostgreSQLWebhook verificationFinanceSettlement filesReconciliation jobsRefund controlsDispute tracking
08Who It Is For

Built for Teams Like Yours

FLAGSHIP
You need payments that finance can also trust

Your product has to accept money and the first attempt marks orders as paid from the browser. Some customers are charged twice, others pay and see an error. Refunds are done in the provider's dashboard and nobody updates the order.

First online payments
Adding local payment methods
Mobile app checkout
Marketplace and split payments
Recurring and saved cards
Changing payment provider
09Questions

What buyers ask before they start

If yours is not here, ask us directly. The first conversation is free and useful whether or not we work together.

Book a call

A merchant account with your chosen provider, or an application in progress, since providers verify the business before enabling live payments. You also need sandbox credentials, and for wallets such as Apple Pay a developer account and domain verification. Which methods you may offer depends on your country, your business type and the provider's approval. We help you prepare, but the agreement is between you and the provider.

The one that serves your customers' preferred methods in your markets at a sustainable cost, and that will approve your business. We compare candidates on method coverage, currencies, settlement speed, fees as published, payout countries and quality of documentation. For products selling in several regions, two providers are sometimes better than one. The choice stays with you, and we integrate whichever provider you select.

Every business that accepts cards has obligations under the card industry's security standard, but their size depends on the integration. With a hosted payment page or the provider's embedded fields, card numbers never reach your servers and the requirements are at their lightest. Handling raw card data yourself brings the full standard. We design for the lightest scope, and your provider confirms what you must attest.

Yes, through a provider that offers them. Local debit schemes are reached through licensed gateways or acquiring banks, and each has its own onboarding, test process and rules for how its option is displayed at checkout. The integration work is similar to cards, with extra attention to redirects and to confirming the result. Your merchant agreement determines which schemes you may enable.

Refunds are started from your own system, by staff with permission, and sent to the gateway with a unique key, so the order, the customer record and the ledger all change together. Partial refunds are supported. Disputes raised by cardholders arrive as webhook events, are attached to the order and alert the team, because providers set deadlines for submitting evidence.

10Related services

Often built together

ReadytoBuildSomethingExceptional?

Every engagement starts with a scoping conversation. It is free, structured, and useful whether or not we work together.

Response within 24 hoursFree consultation & scopingNDA available on request

Premium digital product and engineering studio. We build high-performance web platforms, SaaS applications, mobile apps, and 3D experiences for high-growth companies.

Alpha Expansion is a premium digital product and engineering studio specializing in React development, Next.js development, full-stack development, mobile app development, UI/UX design, and 3D interactive experiences.

We serve industries including SaaS, FinTech, Healthcare, E-commerce, Logistics, and Real Estate.