Marek Nowak
Cloud Deployment
Kubernetes migration with a rollback plan you will not need
Works with Docker
from€1,500.00
1 / 3
Issue, send, chase and reconcile invoices over a clean REST API.
Developers who work with TypeScript, NestJS, PostgreSQL and take scoped work with a fixed price and delivery date.
Cloud Deployment
Works with Docker
A headless invoicing backend: customers, line items, tax rules per jurisdiction, multi-currency with recorded FX rates, PDF rendering, dunning schedules and payment reconciliation. Amounts are integer minor units end to end and the tax engine is table-driven, so adding a jurisdiction is a row rather than a deploy.
Integer money
No floats anywhere. Minor units plus a currency code, in adjacent columns.
Table-driven tax
Jurisdictions are rows. Reverse charge is a column, not a special case in code.
Dunning
Configurable reminder schedules with a stop rule that respects a promise to pay.
OpenAPI 3.1
Generated from the code, so it cannot drift.
4.3
8 reviews
8 verified
Web Application Development
Works with TypeScript, PostgreSQL
Consulting
Works with PostgreSQL
Source Code
Availability, buffers, time zones and no double bookings, ever.
Developer Tool
Refresh-token rotation with reuse detection, TOTP, WebAuthn and a device list.
Source Code
Auth, organisations, seats, Stripe billing and a migration path. Deploy this afternoon.
Source Code
STK push, C2B, B2C and reconciliation, with the callback edge cases already handled.
API
Federated schema, persisted queries and depth limits that stop the obvious attacks.
The architecture is the value here. The default theme needed a day of work before I would show it to a client.
14 found this helpful
Seller replied
A test suite that actually fails when you break something. I checked. That is rarer than it should be.
30 found this helpful
No surprises, no missing files, no "contact us for the full version". Would buy from this seller again.
7 found this helpful
The core is sound. The admin side is thinner than the screenshots suggest, so budget time for that.
17 found this helpful
Seller replied
Everything worked except one migration that needed a manual tweak on Postgres 17. Seller answered within the day.
30 found this helpful