Senior Product Engineer - Backend / Fullstack (3D platform for cultural institutions)

Location: Remote/Hybrid

Type: Full-time

Stage: Post-seed, founding engineering team

Product: 3D platform for cultural institutions (Gaussian Splatting, photogrammetry, marketplace)

Tosee is a platform for experiencing cultural heritage in 3D. We use 3D Gaussian Splatting and photogrammetry to let people walk through museums, explore archaeological sites, and interact with artefacts — from anywhere in the world.

We are moving from a single-institution viewer into a multi-tenant product with marketplace capabilities: institutions will host, curate, and distribute 3D cultural assets under their own branding. Our partners include major Polish national museums and heritage institutions.

About the role

We are looking for a Senior Product Engineer to own the backend and infrastructure layer of Tosee, building it from a sketch into a production system.

This is a hands-on founding engineer role, not a maintenance position. There is no legacy codebase. You are building the backend architecture from the ground up and making the decisions that define how this platform scales.

The CTO handles 3D rendering, scene pipelines, and low-level integrations. You handle everything around that: the APIs, the auth system, payments and licensing infrastructure, asset delivery, and the tooling that lets museums manage their content. You will work alongside a mid-level engineer who handles day-to-day frontend and product surface work.

Your responsibilities

As Senior Product Engineer, you will be responsible for:

• Designing and building the backend architecture from scratch: API design, data modelling, service structure,

• Authentication and security, including:

  • multi-tenant access control and tenant isolation,

  • API key management,

  • secure asset delivery (signed URLs, CDN integration, access-controlled file serving for large 3D assets).

• Payments and licensing infrastructure, including:

  • Stripe or headless commerce integration (Medusa.js, Saleor, or equivalent),

  • subscription and per-asset licensing models,

  • paywall boundary design (what’s free to preview vs. what requires purchase).

• CMS and admin tooling — interfaces for institutions to manage collections, branding, and deployments,

• Infrastructure: CI/CD pipelines, containerisation, deployment, monitoring,

• API layer — exposing clean, well-documented endpoints for the JavaScript frontend,

• Evaluating and integrating marketplace platforms (Shopify, WooCommerce) or recommending headless alternatives where appropriate,

• Co-shaping technical decisions with the CTO and contributing to product direction based on backend feasibility.

Who we are looking for (Must-have)

• Strong backend engineering in Node.js/TypeScript, or demonstrably fast adaptation from another modern stack,

• API design - RESTful at minimum, informed opinions on GraphQL tradeoffs,

• Authentication and security - OAuth flows, role-based access control, secure token management,

• Database design - PostgreSQL as foundation, sound judgement on when to reach for document stores or caching layers,

• Payments integration experience - local vendor experience (przelewy24, blik), legacy ticketing and reporting as a bonus,

• DevOps fundamentals — CI/CD, containerisation (Docker), cloud infrastructure,

• Experience building CMS-like tools, admin panels, or editor interfaces,

• Fluent English (C1+) — working language of the team and all technical communication.

Nice to have

• E-commerce or digital marketplace architecture, especially headless commerce patterns,

• Multi-tenant system design: white-labelling, domain routing, tenant isolation,

• IIIF or cultural heritage data standards,

• Experience with headless CMS platforms,

• Large file delivery: CDN configuration, signed URLs, chunked transfer, storage optimisation,

• Experience working with or selling to cultural institutions or public sector,

• C1+ level of spoken and written Polish.

What we offer

• Senior founding engineer role with direct influence over architecture and product direction,

• Greenfield backend — no legacy code, no inherited technical debt,

• Stack flexibility — Node/TS is the default assumption, but the backend stack is yours to propose and defend,

• High autonomy: small founding team, clear ownership, short feedback loops,

• Meaningful domain: museums, cultural heritage, spatial computing — not another dashboard,

• Remuneration: from PLN 15 000 PLN net/month (B2B +VAT),

• Remote-first, async-friendly,

Red Sky is conducting this recruitment process. The cooperation concerns a newly established start-up.

Recruitment process

1. Interview with HR (application review) - 45 min.

2. Technical conversation with the Founder / CTO ~ 120 min.

   1. Architecture case: how would you design the backend for multi-tenant multimedia asset delivery?

3. Final conversation and terms 30 min.