What does Member of Technical Staff actually mean?

Where the title comes from

Bell Labs used MTS for decades to cover the researchers and engineers who built the transistor era, and the labs that descended from that culture kept it: research institutions, semiconductor companies, storage and systems companies. For most of its life it read as a research-institution formality, the industrial equivalent of a university calling everyone “faculty.”

Then the AI labs revived it. OpenAI, Anthropic, and the generation of companies built in their image hire almost everyone technical under the same three words, and a title that had been fading became one of the most searched job titles in the industry. Like Bell Labs, the AI labs wanted one title for everyone technical.

Why companies choose it

A flat title does three jobs at once.

It keeps level private. A named title broadcasts your seniority to every recruiter with a sourcing tool. When everyone is MTS, an outsider can’t tell the distinguished engineer from someone two years in, which makes the team harder to poach by list.

It flattens status inside. On research-heavy teams the line between “engineer” and “scientist” is where resentment grows. One title removes that line: the person writing CUDA kernels and the person writing the training paper are the same rank on paper, which is how the labs want the room to feel.

It resists title inflation. Startups hand out staff and principal titles years before the scope exists. A company with one flat title never has to take those titles back.

What MTS means at an AI lab versus everywhere else

At a frontier lab, MTS is the whole technical band. The internal ladder still exists, it’s just invisible from outside: offers come attached to a level, levels map to bands, and the spread between the bottom and top of the MTS population is enormous, in scope and in pay. At older companies that never dropped the title, MTS often sits inside a visible ladder, with Senior MTS, Principal MTS, and similar rungs doing the work the flat version refuses to do.

So the same three words mean “we don’t do titles” at one company and “rung four of nine” at another.

How to read an MTS offer

Since the title says nothing, everything you’d normally read from the title has to come from questions.

Ask for the internal level, and the band that goes with it. Every flat-title company has one. It decides your compensation, your scope, and your promotion path, and the company knows the answer even if the recruiter opens with the title.

Ask what the role owns. One MTS posting is research-adjacent infrastructure, the next is product engineering, the next is training runs. The engineers we talk to who regretted an MTS move almost always misread the scope rather than the pay.

Check the numbers by company rather than by title. Levels.fyi is the right place for current figures. The pattern that has held: frontier-lab MTS offers price at or above equivalent staff bands at large public companies, and the equity component carries most of the variance.

MTS on your record

A flat title neither helps nor hurts a career on its own, because future employers read scope. When the title era ends up on your profile, make the scope legible: what you owned, what shipped, what it ran on. A line that says MTS and nothing else forces every future reader to guess, and the guess won’t favor you. We read profiles the same way, so the Eng Scorer ignores titles almost entirely and reads what you built.