WB Serviços — HR operations with legally valid digital signatures.

A field-services company runs on paper it cannot afford to lose: payslips that must be signed, medical certificates, PPE delivery receipts that are the legal defence in a labour claim, and hiring paperwork spread across people who are rarely in an office.

Two constraints shaped everything. A signature has to be verifiable by a third party who has no account in the system. And PPE control under NR-6 is not a stock feature — it is a matrix of what each role is required to wear, tied to every delivery and return.

The document is the unit of work. Any document can require one or several signers, internal or external; signing is confirmed by password and can carry a drawn signature captured on screen; the signature is stamped into the PDF server-side and logged immutably.

• Public validator. Every signed document exposes a hash. Anyone — an auditor, a labour inspector — can open the public page, paste the hash, and see who signed what and when, without an account.
• External signers. People without accounts get a tokenised link: identify, review, sign.
• Self-service hiring. The candidate receives a hashed link, fills in their own record, uploads documents, signs the data-protection term and concludes — with an export to the payroll software the accountant already uses.
• PPE module. Categories, variants, units, a per-role requirement matrix, stock movements, deliveries, returns and signed delivery receipts.

The only polyglot project of the set: a Go API on Fiber and GORM over MySQL, and a SvelteKit front end that also acts as a BFF — its server routes proxy the Go API so no browser ever holds a backend credential.

• PDF signature stamping is done in Go with pdfcpu and gopdf, writing directly into the document rather than appending a certificate page.
• A JWT-authenticated WebSocket channel pushes live notifications.
• The API is documented with Swagger and instrumented with Prometheus — both endpoints are part of the product, not an afterthought.
• Bulk import brings employees in from spreadsheets, and filtered exports leave as ZIP archives.

Payroll, certificates, PPE and hiring live in one place, and the paperwork that used to be a labour-claim liability is now a URL a third party can verify on their own. The job board and candidate pipeline feed the same employee record the rest of the system reads, so a hire never has to be typed twice.