This is linked to the Question "Can I adapt code I wrote for work and release it on open source"

I used to work as a 3D Artist for a company where I sometimes wrote scripts to ease our workflow. Of course that code belongs to my employer. However, if I now were to rewrite the code from scratch at home or maybe at a different company, would I still violate that law?

You could also say, does my ex-boss own just the code, or also the idea?

  • Did you write it from scratch for them? This could just as easily be considered you writing it down from memory.
    – cdkMoose
    Feb 15, 2019 at 14:38
  • I did. In all cases I was the one discovering the issue too. So I'd see room for improvement, go to my supervisors and say "Hey we could work more efficiently if I implemented that" and they'd grant me time to implement it.
    – anon
    Feb 15, 2019 at 16:30
  • And it was never linked to any pre-existing code. Except for the things I wrote specifically for their pipeline, but those are too specific to be of use for me anyways.
    – anon
    Feb 15, 2019 at 16:31
  • So, if you create the same (or very similar) "from scratch" for somebody else, it will look pretty suspicious. If you just repeat the same thing, you are stealing their work.
    – cdkMoose
    Feb 15, 2019 at 16:35

2 Answers 2


First, check your contract. If it's Germany, it's probably written down.

Assuming there is no agreement whatsoever (and I doubt that) then you would be free to redo the work you already did with the knowledge you now have. Redo means you have to do it again with the tools you have available now. No copying of source code files just because they forgot to revoke your access, not using their tools.

A simple example: if you program an e-commerce platform in C#, then switch jobs, you are free to program another e-commerce platform. In C#. Just imagine if you weren't allowed to do that. I programmed a linked list for my very first employer, can I really be banned from writing such data structures in the future? Obviously not.

Exceptions are (and I cannot stress this enough) your contract and any laws that apply, like patent laws. If that e-commerce site was such a miracle that they had it patented, then you are not allowed to copy it, whether you previously worked there or not.

If your boss though it would be great to sell shirts next to socks in that web shop? There is nothing prohibiting you from opening your own business and doing exactly that. Except for maybe your contract.

  • I think there would be a distinction between a data structure and a system.
    – cdkMoose
    Feb 15, 2019 at 14:40
  • 1
    @cdkMoose Where would that distinction be? How much code is there to write until the data structure becomes a fancy "system" and can be sold as a database for millions?
    – nvoigt
    Feb 15, 2019 at 14:48
  • @nvoight, it's not always easy to tell, but in this case we could start with: one is documented in literally hundreds of computer science and programming books, the other was written with specific knowledge of workflow at his employer
    – cdkMoose
    Feb 15, 2019 at 14:55
  • I don't know... a database is a really massive product, yet it's hardly something one single employer can claim to have invented. I could work at MS, switch to Oracle and then build my own database, if none of them put any specifics in my contract (which they undoubtedly would do).
    – nvoigt
    Feb 15, 2019 at 15:10

It depends.

How specific is the "idea" to the organization?


  • If the idea is to improve the efficiency of a specific working model by introducing a new logical path using some specific tooling - well, that idea / concept might be owned by your organization. The organization might have spent some time and resource finding out the problem exists and then again used their resource to produce a solution. You happened to be the part of the team which worked on this - so this does not make the idea yours.

  • If the idea is to automate some download from internet and using that as a source for random noise - well, that's a common idea and any code you (re) write would be OK.

To sum it up: If the idea is available or derivable without a dependency on the work you have done in your previous organization, then any code you write based on that idea would be OK. Any conclusion or observation (however small it may be) which (can potentially) lead back to the work done in your previous organization - STOP and abandon the idea.

Disclaimer: IANAL

  • @JeffUK OK, I'd rephrase to "owned". Feb 15, 2019 at 15:17
  • @JeffUK Patent? Not necessarily. The everyday work we do (like design idea, or an upgrade plan to a system) cannot be copyrighted, but it's still not able to be circulated publicly. Feb 15, 2019 at 15:20
  • OK, some tips on why this answer is not useful? Feb 15, 2019 at 15:27
  • I didn't downvote it, but as a non-native speaker its quite hard to read :/
    – anon
    Feb 15, 2019 at 16:28

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