File / Reijnen, J. Amsterdam · NL

A developer who's
also run the operation.

Independent developer focused on ecommerce operations, automation, and practical software. Most of what I build ends up sitting between a business problem and the tool that should already exist for it.

Background

I started in software testing and quality work, which is where I learned to look at systems the way they actually behave instead of the way they're documented. From there I moved into broader technical work: automation, internal tooling, product data, and small products that take repeated work and make it routine.

I currently work inside large retail ecommerce environments focused on product information, integrations, and operational tooling. Alongside that I run a few of my own ecommerce brands, which keeps me close to listings, logistics, photography, supplier data, and the small recurring decisions that end up shaping how a store actually runs.

What I help with

  • Turning recurring manual ecommerce work into tools or automations operators can actually trust.
  • Structuring product data so it can support listings, storefronts, marketplaces, and internal review.
  • Building internal dashboards and admin interfaces around real decisions instead of generic CRUD.
  • Integrating systems that should talk to each other but don't, without adding a fragile middle layer.
  • Creating interactive installations and event technology where software, hardware, and live use all have to work together.

How I work

Understand the workflow first. Find the brittle part. Build the smallest useful version. Improve it with real feedback. I prefer systems someone else can read and run later, and I try to keep the business logic visible rather than buried.