Employment history: job title I am currently filling out an application for a lecturer position in the UK, which includes a section on employment history.

Previously I was employed at a Russian university where my official job title was an engineer. However, the work that I did correspond more to a research assistant. The problem is that in Russia you need to be a PhD and go through an official selection procedure (that means for an organisation to open position, to select a pool of candidates, etc.) to get a research assistant position. So usually if your professor gets a grant, he/she usually tries to hire you on a less "complex" position from a bureaucratic point of view (especially if you are not a PhD).

Obviously, I don't want to describe all this country-specific stuff in my application. How do you think, is it OK to put a job title "research assistant" in the application? Are the universities likely to verify this information?
Do not lie.

You never know who is going to read your application. What if the committee includes a Russian person who is familiar with the Russian system and spots the inconsistency right away?

I would write the actual job title and then describe the tasks you had there, emphasizing that they were research tasks.