I have been a Data Scientist for more than 7 years now. My positions so far have been "Big Data Scientist", "Data Science Architect", "Senior Data Scientist" (in that order).

I do not only have technical responsibility for my own work, but also for other Data Scientists work (but mostly technology-wise). My responsibilities include thinking about future projects, talking to customers if required (e.g. in technical pre-sales), making sure the collaboration with other departments goes smoothly (including giving them guide lines) and helping the senior management developing strategies regarding data science topics. My specialty is in machine learning (both practical, as well as academic-theoretical ML), but I also develop (micro-service) the software architecture for all our analytics projects. I introduced all machine learning to my employer and are the most senior data scientist in the company. I also made sure that the entire machine learning infrastructure would be build.

To reflect all those responsibilities, my title shall be "updated" from "Senior Data Scientist" to... well that is the question. I was asked to what exactly. I thought "Lead Data Scientist" would be the title to go for, but my research also unearthed "Principal Data Scientist", which seems to be much more common than "Lead Data Scientist".

Although I was a consultant in previous jobs, in my current employment I am not in the consultant industry. My employer builds software that is sold/licensed. I know that in the consultant industry we had the "principal" after the "senior", but I read somewhere (but that is a while ago) that outside the consultant industry, the "lead" is more common. But my research this morning suggests that the "Principal ..." is more common everywhere. I am confused.

What is the difference, which one is closest to my work, and - mostly - which has more prestige?

Side-note: My responsibilities will not change, as I already have quite a few, that is why I wrote "reflect". However, my salary will go up by 10-15% (we will see what they decide on) to financially honor my responsibilities and accomplishments. I have read somewhere that a "Principal ..." gets more money while a "Lead ..." is just "nice sound", but I don't know.

Not sure if important, but I work in Germany, while my title is English.

  • 10
    Titles are so meaningless that your company didn't even bother thinking about it... seriously choose what you prefer, use a synonyms dictionnary if you want or just come with an even more prestigious one (I would suggest "Data Science Superstar"), I don't think anybody could care less...
    – Laurent S.
    May 22, 2021 at 15:00
  • BTW you have a misspelling "principle" often in the text. It should be "al". (This is a common mistake amongst English-speakers BTW.) mfg
    – Fattie
    May 22, 2021 at 15:03
  • 3
    FWIW "Principal" is far more important than "Lead". Lead merely means you are a team lead. Principal means you are the actual inventor / creator / source of the technology.
    – Fattie
    May 22, 2021 at 15:04
  • 4
    @Fattie That's far from universal. Basically, in this industry the titles are so mixed up between different companies that lead, principal, staff, and senior have no meaning outside that org. Principal definitely does not mean creator though- it means a high level dev/architect, although I know companies where staff is a higher rank. May 22, 2021 at 21:52
  • 2
    @Fattie and compliment v. complement... plus so many others - down to education or the latest excuse: autocorrect (aka auto f-up)
    – Solar Mike
    May 24, 2021 at 11:13

4 Answers 4


In my company at least, those are very different roles

I work for a company where more than half the employees are data scientists/machine learning engineers.

Principal is someone who is very senior and very experienced, but manages no people or projects. It is the title of the most experienced individual contributor in a particular job role.

Lead is a managerial role. So you have people under you.

  • 1
    And local laws can dictate whether the word "Principal" has a legal meaning. I know the word "Engineer" has specific requirements in some countries, and you can't just randomly put that on a job title.
    – Nelson
    May 23, 2021 at 9:29
  • 1
    Exactly. If OP wants future management positions, go with lead or better "Head of". If OP wants to brand himself as a guru/rockstar, go with Principle.
    – paulj
    May 28, 2021 at 13:37

Typically, lead consultants are in charge of supervising a team of junior/'regular' level consultants, while principal consultants are at the top of the organization and supervise a number of teams, each headed by a lead consultant.

However, where I work we have principals who are not above leads. For us, a lead role is as specified above, but a principal is someone who is very proficient in what they do, and have no direct reports.

In your case, it appears the titles are just a kind of "badge of honour", and don't really mean anything in terms of superiority.

  • You are right: In my case it is mostly about the "badge of honor".
    – Make42
    May 24, 2021 at 12:51

Imagine a company X, that has defined a complete corporate ladder that describes the titles, responsibilities, and the associated pay scales.

Imagine a company Y that has not completely mapped the the titles, responsibility and pay.

If you work for company X. The answer is found by looking at the corporate documents.

If you work for company Y, and it sounds like you do. The two titles contain words with no defined relationship. Pick the one you like, and the one they will let you use.

I have worked for places where a Chief was the lead person of that type on a project. While a Principal was never assigned to any project. They only were called in when help was needed. No idea which one paid better. Sometimes it seamed like the principal lacked people skills, or it was a place to hide a person who lacked some area of experience. Other times it was a place to move a very experienced person so that younger employees could gain experience.


For my understanding, "Principal Data Scientist" means you are doing the mainly part in the actual project, and you are able to handler most of the difficult part. "Lead Data Scientist" means you are able to lead other junior data scientist to work on a project, guiding them. But the "Principal Data Scientist" has no such responsibility

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