ShopMyESIM: an eSIM price comparison platform for travellers.

The problem

What I did

• Built a trip planner (where, how long, how much data) that suggests a data allowance and opens results already filtered to that trip.
• Built destination search that matches alternative country names, dual-range slider filters, sorting, side-by-side comparison, region pages for multi-country plans and provider profiles.
• Tracked clickouts with affiliate sub-IDs and UTM tags, and added a sticky trip bar that keeps the trip summary and lowest price on screen while scrolling.
• Brought in live plans from 7 brands: Airalo, Holafly, Nomad, Jetpac, Yesim, Roamless, and one more through its partner API. That is 5,000+ plans across 190+ countries, with full price history and automatic archiving of discontinued plans.
• Added sync safety checks: a sync that would archive more than half a brand’s plans is cancelled, a sync with zero usable plans fails instead of reporting success, and fetching stops when a site starts blocking requests.
• Built “Email me these plans” and “Email me this comparison”, a trip reminder sent 3 days before departure with fresh prices, and an eSIM phone checker that recognises the visitor’s device (iOS version, Android client hints, Samsung model codes). None of it needs an account, and all of it has consent tracking, one-click unsubscribe, rate limits and spam protection.
• Wrote the traveller authentication myself, with scrypt password hashing and hashed session tokens. Travellers save plans and see how the price has moved since, save searches and delete their own account.
• Built an operations console of 14 admin modules with role-based access (Super Admin, Editor, Analyst): KPI dashboard, catalogue editing, CSV import, promotions, ranking controls, clickout log, traveller CRM, leads, API sync controls, team management, system health and an audit log.
• Traced page hangs and intermittent 500 errors to Supabase’s connection pooler. I measured 15 of 18 requests hanging in transaction mode against 0 of 18 in session mode, and switched the app to session mode.
• Moved the serverless functions into the same region as the database, so each page makes one cross-region hop instead of one per query.
• Found Supabase’s default REST API exposing admin password hashes and session tokens, and wrote a lockdown script that revokes 208 grants.
• Fixed Airalo prices arriving in yen, because the sync ran from a Tokyo server, by forcing USD pricing.
• Set up 100+ automated browser checks across 5 test suites, scripted WCAG AA contrast checks, 44px touch targets and loading skeletons.
• Wrote the scope, a 25 to 30 day timeline and a testing plan for the client as a branded PDF, and took the design through three iterations to the ShopMyESIM brand: logo, palette, icons and link previews.
• Wrote a handover pack: an owner guide, an operator walkthrough of every admin screen, developer notes, an email setup guide and an API requirements document for partner brands.

Timeline

Sep to Nov 2026, about 8 weeks so far. The work continues.

1. 14 to 15 Sep 2026

   MVP: the public site, accounts, admin console and deploy tooling.

2. 5 to 12 Oct 2026

   Design: design system, destination photography, UI polish and a redesign.

3. 13 Oct 2026

   Hardening: fixed the pooler errors and hangs, and moved the functions next to the database.

4. 26 to 28 Oct 2026

   Real data and launch: the partner API, website syncs for 3 brands, the ShopMyESIM brand, go-live and handover.

5. 3 to 10 Nov 2026

   Growth features: email capture, trip reminders, the phone checker, the sticky trip bar and Mumbai infrastructure.

6. 11 Nov 2026

   Catalogue expansion: added Jetpac, Yesim and Roamless.

Results

eSIM brands compared

7

Plans

5,000+

Countries

190+

Admin modules

14

Automated browser checks

100+