Software Engineer, B2B SaaS Platform (TypeScript)

About the role

Job Summary

We are looking for a Founding Software Engineer to build a new SaaS platform for wholesale businesses covering inventory, purchasing, a B2B customer ordering portal, CRM and integrations with Xero, Shopify, Royal Mail and Amazon etc. You will be the first technical hire and will own the codebase. This is not a blank\-page role: the architecture is designed and documented, a working database schema and tested pricing engine already exist, and a full product prototype has been validated with real wholesalers. Your job is to turn that foundation into a production system with paying customers, working directly with the founder and shaping the product as well as the code.

Duties

* Build the core platform in TypeScript: a NestJS API and Next.js front end, backed by PostgreSQL and Redis, structured as a modular monolith (deliberately not microservices). * Implement the operational heart of the product: authentication and roles, product catalogue, sales orders with stock reservations, purchasing and goods receipt, and the pricing engine integration. * Develop the B2B customer ordering portal with customer\-specific pricing, live stock availability and credit control. * Build the integration layer, starting with Xero, followed by Shopify, Royal Mail (Click \& Drop) and Amazon SP\-API etc. * Design and evolve the PostgreSQL schema, including row\-level security for tenant isolation and an append\-only stock ledger. Comfort with transactions and locking matters here. * Implement and document RESTful APIs (OpenAPI) used by both our own front ends and customer integrations. * Own deployment and operations on AWS using managed services, with CI/CD through GitHub Actions and infrastructure as code. * Write unit and integration tests as part of everyday work; integration tests run against a real Postgres database in CI. * Work directly with the founder to turn product decisions into working software, and push back when you think something in the plan is wrong.

Experience

* Proven experience building and running production SaaS. * Strong TypeScript across the stack: Node.js on the back end (NestJS preferred) and React on the front end (Next.js preferred). * Genuine PostgreSQL depth: transactions, locking, indexing and ideally row\-level security, not just ORM\-level knowledge. * Experience deploying and operating systems on AWS (or equivalent cloud) including monitoring, migrations and incident handling. * Solid API design experience (REST/OpenAPI); experience integrating third\-party platforms such as Xero, Shopify or Amazon is a strong plus. * Experience with inventory, ordering, ERP or e\-commerce systems is desirable but not essential. * Familiarity with multi\-tenant SaaS architecture is a strong advantage. * A testing habit: you write tests because that is how you work, and you treat a green CI pipeline as the gate for shipping. * Comfortable owning a codebase solo in an early\-stage environment and managing your own priorities.

This role is a chance to build a product from the ground up without the usual blank\-page risk: the groundwork is done, the market is real, and through our existing business we already have access to early customers.

To apply, send a CV and a short note about the most complex production system you have built and run, including what broke and what you would do differently. A link to code or a live product is worth more to us than a cover letter. No agencies, please.

Pay: £50,000\.00\-£65,000\.00 per year

Benefits:

* Casual dress * Employee stock ownership plan * Free parking * On\-site parking * Work from home

Work Location: Remote