CASE STUDY · 01
Chave Móvel Digital
- Government
- 2022 — 2025
- 3 yrs
- Backend Developer
USERS
8M+
Citizens authenticating in production daily.
CODEBASE AGE
10yrs
Legacy .NET Framework 4 system extended without rewrite.
REGRESSIONS
0
Across 3+ years of feature work and migrations.
INTEGRATIONS
12
REST + SOAP services, SSO and gov data layers.
└ OVERVIEW
Backend on Portugal's national authentication service. 8M+ citizens sign in through it to reach every public service in the country.
└ Problem
Keep extending a ten-year-old .NET Framework 4 system that 8M+ citizens depend on, without breaking anything, while shipping new auth flows.
└ Solution
Worked the full backend. REST/SOAP integrations, auth flows, SQL Server and MySQL queries. Security and performance were non-negotiable on every call.
└ Impact
Zero regressions in three years on a system 8M+ citizens use daily.