Vendor Lock-in

Vendor Lock-in is the situation where a company becomes dependent on an external supplier to the point that switching becomes extremely costly or technically complex. In the IT context, it occurs when the code, architecture or system knowledge are in the supplier’s hands, not the client’s.

How it works #

Lock-in establishes itself gradually: the supplier writes code with their own conventions, uses proprietary or undocumented technologies, and the internal team is not involved in development. When the supplier leaves — by choice or dismissal — they take the know-how with them. The client is left with software they don’t understand, can’t maintain and can’t evolve without re-engaging the same supplier or starting from scratch.

What it’s for #

Understanding vendor lock-in is essential for making strategic decisions about outsourcing and software development. Every project should include mitigation measures: internal documentation, code reviews, internal team involvement, source code ownership.

When to use it #

The term describes a risk to avoid. The main countermeasures are: keeping critical know-how internally, preferring open and standard technologies, ensuring intellectual property ownership of the code, and always evaluating the “buy vs build” option before starting large-scale custom projects.