Efectiback

The problem

Small businesses need to issue invoices that SUNAT accepts without relying on an accountant or a slow portal, and the systems they already use (POS, ERP, online store) must be able to integrate by API.

What I built

I built the platform end to end: a Java library with UBL 2.1, XAdES signing and a SOAP client; a Spring Boot API with hexagonal architecture; a client portal and a back office in Angular; and the landing page in Astro.

Outcome

In use by real clients. More than 350 automated backend tests, and issuing verified against SUNAT’s beta environment with an accepted CDR.

Decisions that mattered

1. 01

   The queue lives in Postgres

   Sending to SUNAT uses a queue table with FOR UPDATE SKIP LOCKED and exponential-backoff retries: no RabbitMQ, no extra infrastructure.

2. 02

   One validator per document type

   Invoices, receipts and notes validate with their own rules, extracted from SUNAT’s official spreadsheet. An error is rejected with HTTP 422 before queuing.

3. 03

   Modular monolith, not microservices

   A single deployment with bounded contexts (issuing, identity, subscriptions). The engine is a library without Spring, tested on its own.

4. 04

   Encrypted secrets

   Each company’s digital certificates and SOL key are stored encrypted with a master key, and the session uses an HttpOnly cookie.

5. 05

   Minimal running cost

   Backend on Cloud Run, database on Supabase, files on Cloudflare R2 and front ends on Cloudflare Pages.

Technologies

• Java 21
• Spring Boot
• PostgreSQL
• Angular
• Cloud Run
• Cloudflare R2
• Astro