Project 04 · Case study
eSIM commerce product
A standalone product vertical from catalogue and pricing through payment, provisioning, delivery, and admin operations.
Full-stack engineer · end-to-end vertical ownership
Within the travel-commerce engagement, I built a standalone eSIM store as an end-to-end product vertical. The work did not stop at checkout: catalogue, retail pricing, payment, fulfilment, customer delivery, public acquisition pages, and administration all had to form one reliable path.
01 · Product shape
A commerce product with a fulfilment path behind it
The product needed a public catalogue, destination landing pages, inline authentication during checkout, a payment path, and an admin operations console. The customer experience was only credible if the order could move through provisioning and delivery afterward.
I worked across the data model, provider client, public store, pricing, checkout, fulfilment jobs, delivery email, and the backoffice surface used to operate the product.
02 · Engineering decisions
Keep price, payment, and fulfilment connected
The catalogue used Redis stale-while-revalidate caching. Retail pricing was minor-unit aware. Checkout included an authenticated order path, and payment webhooks fed an idempotent fulfilment flow.
Provisioning ran through a queue worker and delivery continued through email. Those are not separate implementation details—they are the product path after the customer presses pay.
01 · Catalogue
Public inventory with a deliberate cache boundary
The store used cached catalogue data while retaining a provider-facing product and region layer behind it.
02 · Payment
A durable handoff into fulfilment
An idempotent payment-webhook branch connected checkout to provisioning without turning repeated delivery into a customer risk.
03 · Operations
Customer delivery and administration in the same vertical
Provisioning, delivery email, order visibility, and the operations console kept the post-purchase work close to the product.
03 · What it proves
Full-stack delivery includes the operational end of the journey
This vertical is a useful example of how I work: I can take a product area from schema and integration through customer experience, transactional handling, asynchronous work, and the internal tools required to run it.
Evidence treatment · contribution map
The parts of the product I worked on
Scope is deliberately grouped by my ownership boundary. It is not a claim about the whole system.
Built end to end
- Provider client, catalogue, and data model.
- Retail pricing, checkout, and payment webhook flow.
- Queued provisioning and delivery email.
Delivered
- Public store and destination landing pages.
- Admin operations console and order management.