Signing Service

A small full-stack service that accepts signing requests, runs them through a policy check, and returns a signed result. It models a real flow: coordinator → policy → signer, in miniature. The "signer" is a stub: it returns a deterministic fake signature, not real cryptography. You do not need any blockchain or crypto knowledge to work on this.

• Backend: Go HTTP service (server/), in-memory storage, no external deps.
• Frontend: React + TypeScript via Vite (web/); a one-screen dashboard to submit requests and view results.

Running it

You'll need Go (1.22+) and Node (18+).

make install   # installs frontend deps (one time)
make dev       # runs backend on :8080 and frontend on :5173

Then open http://localhost:5173.

Other targets: make server, make web, make test (backend tests), and make check (backend tests + frontend typecheck) — the quickest way to verify the whole stack after a change.

API

Method	Path	Description
POST	/v1/signing-requests	Create a signing request. Body: { "walletId": string, "payload": string }. Returns the signed request.
GET	/v1/signing-requests	List all requests.
GET	/v1/signing-requests/{id}	Fetch one request, or 404.

Allow-listed wallets: wallet-alpha, wallet-beta, wallet-gamma. The policy check rejects empty payloads, empty wallet IDs, and wallets that aren't allow-listed (422).

curl -s localhost:8080/v1/signing-requests \
  -H 'Content-Type: application/json' \
  -d '{"walletId":"wallet-alpha","payload":"hello"}'

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Before your interview

Please confirm the service runs on your machine: make install, then make dev, then open http://localhost:5173 and submit a request. If anything fails to boot, let us know ahead of the session so we can sort it out off the clock.

You'll receive the task itself at the start of the interview.