CTO Needed: Accounting SaaS Backend

I’m building an accounting platform aimed squarely at professional accountants and I need someone who can wear the CTO hat from day one. Your first mission is to shape the entire back-end architecture and then guide (or code) the initial release.

Core product scope
The MVP must let users create and send invoices, track expenses in real time, and generate clear, customizable financial reports. Everything has to be secure, multi-tenant, and ready to scale once we land our first cohort of firms.

Tech direction
I’m stack-agnostic right now. Whether you prefer Node.js, Python / Django, Ruby on Rails—or something you can justify—bring the reasoning and I’ll listen. What matters is long-term maintainability, a clean API layer for future mobile apps, and straightforward DevOps.

What I need from you
• A high-level technical roadmap covering data models, service boundaries, and key third-party integrations (payments, bank feeds, etc.)
• An MVP back end with documented REST or GraphQL endpoints, tests, and CI/CD set up in GitHub or GitLab
• Deployment scripts/infrastructure-as-code so we can push to a cloud environment (AWS, GCP, or Azure—your call, explain why)
• Clear technical documentation that lets additional engineers onboard quickly

Acceptance criteria
1. Invoicing, expense, and reporting endpoints return expected JSON payloads and pass agreed unit/integration tests.
2. Multi-tenant data isolation is demonstrable via test accounts.
3. CI pipeline builds, tests, and deploys to a staging environment with one command.

If steering the technical future of a green-field accounting SaaS excites you, let’s talk about timelines and how you like to work.