My Achievements in This Project:

• Developed and maintained payment processing for a high-volume e-commerce checkout serving millions of customers.

• Implemented subscription billing for contact-lens auto-replenish (1 / 3 / 6 month cycles, pause, change, and cancel).

• Integrated multiple payment methods — cards, digital wallets, and BNPL (Klarna / Affirm) — into a single checkout flow.

• Supported vision insurance, FSA/HSA, coupons, and installment logic applied at checkout.

My Role in This Project:

• Backend engineer focused on payment systems, subscription lifecycle, and related business logic.

Problems I Solved:

• Unified checkout across credit cards, PayPal, Apple Pay, Amazon Pay, Google Pay, Klarna, and Affirm with consistent order and capture flows.

• Designed recurring charges for contact-lens subscriptions, including skip/pause/cancel and “no charge when paused or cancelled”.

• Handled prescription-gated fulfillment — subscriptions pause when an Rx cannot be verified, in line with US contact-lens rules.

• Kept payment, refund, and try-on/return money flows reliable under high traffic and promotion-heavy checkout.

Technologies Used: PHP, payment gateway APIs, subscription billing, REST integrations, MySQL.

Methodology: Agile methodology with daily Scrum meetings and 2-week sprints.

About Project

GlassesUSA.com is a major US/Canada e-commerce platform for prescription eyeglasses, sunglasses, and contact lenses, with designer brands, 60-day home try-on, 365-day warranty, free shipping, and 3M+ customers. Shoppers can pay by card, digital wallet, or installments; apply vision insurance and FSA/HSA benefits at checkout; and subscribe to recurring contact-lens shipments.

My Role & Contributions

As a backend engineer I owned payment and subscription logic: provider integrations, checkout capture/authorization, recurring billing for contact-lens auto-ship, coupon and insurance-benefit application, and account-side pause/change/cancel. I worked on reliable money movement — charges on shipment, refunds on returns, and edge cases such as expired prescriptions and prepaid cards that cannot start a subscription.

Key Features and Problem-Solving

01. Multi-Provider Checkout: Built backend payment flows for major credit cards and wallets (PayPal, Apple Pay, Amazon Pay, Google Pay), plus Buy Now, Pay Later via Klarna (Pay-in-4) and Affirm, so a single order could complete through the correct provider.

02. Contact Lens Subscriptions: Implemented recurring billing for auto-replenish: ship every 1, 3, or 6 months, charge on shipment, and allow customers to pause, change, or cancel from My Account with no cancellation fee.

03. Insurance & Benefits at Checkout: Supported applying vision-insurance benefits and FSA/HSA eligibility at checkout, including coupon stacking rules and itemized receipts for reimbursement.

04. Subscription Compliance: Tied billing to prescription validity — pause or stop shipment when an Rx cannot be verified, and block prepaid cards from starting a subscription.

05. Refunds & Try-On Flows: Aligned payment/refund logic with 60-day home try-on, returns, and insurance benefit restoration so money and benefits stayed consistent after cancellations.