Looking for Senior Developer – Shopify + Centralized Custom Checkout (EU Payments)

[fixer78]

Hi everyone,


I’m looking for a senior developer to collaborate on a payment-heavy e-commerce project.

Project overview​

• Multiple Shopify Standard stores (used for catalog & inventory)
• Centralized custom checkout hosted on a single whitelisted subdomain
• Embedded card payment form (iframe, no redirect)
• Checkout receives sessions from multiple stores and processes payments centrally
• After successful payment, orders are created in Shopify via Admin API
• Strong focus on conversion rate, UX, and reliability

Tech scope​

• Backend for checkout session management and price validation
• Integration with an EU card payment gateway using embedded iframe
• Proper handling of server-to-server payment notifications
• Shopify Admin API (orders, inventory, customers)
• Clean, compliant architecture (no card data ever touches our servers)

Requirements​

• Proven experience with custom checkouts
• Solid experience with payment gateways (embedded / iframe based)
• Comfortable with Shopify Admin API
• Backend stack: Node.js or PHP
• Strong understanding of edge cases (idempotency, retries, partial failures)

Important​

This is not a basic Shopify task and not a template job.
I’m looking for someone who understands payments infrastructure, not just frontend.


DM me with:

• Relevant experience
• Preferred tech stack
• Availability

Serious developers only.

 

[ashikdotme]

Hi, this project fits well with my experience.

I’ve worked on custom checkout systems, embedded iframe payments, and Shopify Admin API integrations, including centralized checkout flows and server-to-server payment handling. I’m comfortable with PCI-safe architectures, idempotency, retries, and handling edge cases in payment systems.

Tech stack: PHP (Laravel) / Node.js / Shopify
Availability: Ready to start and commit long-term

I’ve sent you a DM with more details and relevant experience.

Thanks.

 

[CodiBot]

Hi everyone,


I’m looking for a senior developer to collaborate on a payment-heavy e-commerce project.

Project overview​

• Multiple Shopify Standard stores (used for catalog & inventory)
• Centralized custom checkout hosted on a single whitelisted subdomain
• Embedded card payment form (iframe, no redirect)
• Checkout receives sessions from multiple stores and processes payments centrally
• After successful payment, orders are created in Shopify via Admin API
• Strong focus on conversion rate, UX, and reliability

Tech scope​

• Backend for checkout session management and price validation
• Integration with an EU card payment gateway using embedded iframe
• Proper handling of server-to-server payment notifications
• Shopify Admin API (orders, inventory, customers)
• Clean, compliant architecture (no card data ever touches our servers)

Requirements​

• Proven experience with custom checkouts
• Solid experience with payment gateways (embedded / iframe based)
• Comfortable with Shopify Admin API
• Backend stack: Node.js or PHP
• Strong understanding of edge cases (idempotency, retries, partial failures)

Important​

This is not a basic Shopify task and not a template job.
I’m looking for someone who understands payments infrastructure, not just frontend.


DM me with:

• Relevant experience
• Preferred tech stack
• Availability

Serious developers only.

Hello,

This is exactly the kind of project I specialize in.

I’m a senior backend-focused developer with deep experience in payment-heavy e-commerce systems, including custom centralized checkouts, embedded/iframe-based card payments, and post-payment order creation via APIs.

Your architecture (multiple Shopify stores → centralized custom checkout → Admin API order creation) is familiar territory, including:
✔ Secure checkout session management
✔ Server-side price & inventory validation
✔ Embedded iframe payment gateways (no redirects)
✔ Webhook handling & S2S payment notifications
✔ Idempotency, retries, and partial-failure recovery
✔ Clean, compliant flow (no card data touching servers)

Backend stack: Node.js (preferred) or PHP
Strong focus on conversion rate, UX stability, and payment reliability.

This is clearly not a basic Shopify task, and I understand the risks and edge cases involved in payment infrastructure.

You can review my services here:
Sales Thread:
https://www.blackhatworld.com/seo/premium-development-automation-custom-websites-web-apps-ai-solutions-software-development-more-codiwiki.1732441/

I’ve sent you a detailed PM with relevant experience and availability.

Looking forward to discussing this.

 

[Rankifydev]

Hi everyone,


I’m looking for a senior developer to collaborate on a payment-heavy e-commerce project.

Project overview​

• Multiple Shopify Standard stores (used for catalog & inventory)
• Centralized custom checkout hosted on a single whitelisted subdomain
• Embedded card payment form (iframe, no redirect)
• Checkout receives sessions from multiple stores and processes payments centrally
• After successful payment, orders are created in Shopify via Admin API
• Strong focus on conversion rate, UX, and reliability

Tech scope​

• Backend for checkout session management and price validation
• Integration with an EU card payment gateway using embedded iframe
• Proper handling of server-to-server payment notifications
• Shopify Admin API (orders, inventory, customers)
• Clean, compliant architecture (no card data ever touches our servers)

Requirements​

• Proven experience with custom checkouts
• Solid experience with payment gateways (embedded / iframe based)
• Comfortable with Shopify Admin API
• Backend stack: Node.js or PHP
• Strong understanding of edge cases (idempotency, retries, partial failures)

Important​

This is not a basic Shopify task and not a template job.
I’m looking for someone who understands payments infrastructure, not just frontend.


DM me with:

• Relevant experience
• Preferred tech stack
• Availability

Serious developers only.

Hi, I have sent you a private message with my experience, tech stack, and availability. Please check it when you get a chance. Thank you

 

[Adult-HTML]

Hey, just sent you a PM, feel free to check it when you have a moment.
Our team has been working on web projects of all sizes since 2009. We'd be happy to assist you!

Our marketplace thread:
https://www.blackhatworld.com/seo/a...evelopment-partner-for-your-business.1452577/
*Please, note that we work on both, adult and mainstream projects.

 

[Link Builder007]

Hi everyone,


I’m looking for a senior developer to collaborate on a payment-heavy e-commerce project.

Project overview​

• Multiple Shopify Standard stores (used for catalog & inventory)
• Centralized custom checkout hosted on a single whitelisted subdomain
• Embedded card payment form (iframe, no redirect)
• Checkout receives sessions from multiple stores and processes payments centrally
• After successful payment, orders are created in Shopify via Admin API
• Strong focus on conversion rate, UX, and reliability

Tech scope​

• Backend for checkout session management and price validation
• Integration with an EU card payment gateway using embedded iframe
• Proper handling of server-to-server payment notifications
• Shopify Admin API (orders, inventory, customers)
• Clean, compliant architecture (no card data ever touches our servers)

Requirements​

• Proven experience with custom checkouts
• Solid experience with payment gateways (embedded / iframe based)
• Comfortable with Shopify Admin API
• Backend stack: Node.js or PHP
• Strong understanding of edge cases (idempotency, retries, partial failures)

Important​

This is not a basic Shopify task and not a template job.
I’m looking for someone who understands payments infrastructure, not just frontend.


DM me with:

• Relevant experience
• Preferred tech stack
• Availability

Serious developers only.

I have experience with custom checkouts and embedded payment gateways for Shopify.
Please DM me.

 

[sansarahub]

Hi there,

I have extensive experience working on custom checkouts and integrating payment gateways, particularly for Shopify-based e-commerce systems. I’ve handled complex scenarios like centralized custom checkouts, embedded card payment forms, and Shopify Admin API integrations.

Here’s a breakdown of how I can help:

• Custom Checkout Expertise: Built and optimized custom checkout flows, ensuring smooth user experience and high conversion rates.
• Payment Gateway Integration: Worked with EU card payment gateways using embedded iframes and properly handled server-to-server payment notifications.
• Shopify Admin API: Proficient in managing orders, inventory, and customers through Shopify’s Admin API.
• Tech Stack: Comfortable working with Node.js and PHP for backend development, ensuring clean, compliant architecture with no card data stored on the servers.
• Edge Cases Handling: I understand the importance of idempotency, retries, and partial failures in payment systems and have handled these effectively.

Let me know your availability and how we can collaborate on this project!

 

[webow]

Hi,
I have understood your requirments.
I have sent you a proposal via DM.
Thank you.

 

[phpbuilt]

Our team gives you a complete pacakge.

*Website design and development
*on-site seo
*technical seo
*off-site seo.

If you already have a website , no worries we can do the SEO part.

All handled inhouse .

Please get in touch if you're interested.