Exsited / AutoBill
Bit Mascot
An enterprise subscription-billing and accounting platform. I authored its versioned public REST API and the shared framework other teams built on.
- Grails
- Groovy
- Java
- MySQL
- Redis
- RabbitMQ
- Vue.js
Highlights
- Designed and shipped the versioned public REST API (v4) across 116 business entities and roughly 370 endpoints: signed cursor pagination, Redis-backed idempotency keys, 139 typed request objects, optimistic concurrency, and a 23-code error envelope.
- Built a reusable filtering, sorting, and field-projection layer (13 operators with per-type validation, response masking) adopted unchanged by 24 list endpoints with zero per-module configuration.
- Cut list-endpoint database load by an order of magnitude, from 102 to 5 SQL statements per page on the notes API, by replacing per-row lookups with batched foreign-key loaders across roughly 20 endpoints.
- Sole author of the OData v4 analytics feed (Apache Olingo, 19 entities) that let customers query billing data from Power BI, including a filter-expression translator with 11 operators and 13 functions.
- Largest contributor to an 893-permission access-control model, and built the batch billing operations centre (invoice runs, payment runs, dunning, direct-debit) with execution history and live progress.