Praise be to Allah.
With regard to concealing and not mentioning some work experience when submitting your resume to a company for which you would like to work, there may be two scenarios:
The first scenario is when the company has stipulated that you should mention all your experience and not conceal any of it. In that case, you should note that the Muslims are bound by their conditions, so the job applicant should not conceal anything.
That is because of the hadith of Abu Hurayrah, who said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “The Muslims are bound by their conditions.” Narrated by Abu Dawud (3594); classed as sahih by al-Albani in Irwa’ al-Ghalil (5/142).
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
The Qur’an and Sunnah enjoin fulfilling promises, conditions, covenants and contracts, and rendering trusts, and being careful about that. And they forbid deceiving, breaking promises and acting treacherously, and give a stern warning to the one who does that.
As the principle of fulfilling promises and adhering to covenants is something that is enjoined, it is known that in principle, covenants and conditions are valid. End quote from al-Qawa‘id an-Nuraniyyah (p. 272).
The second scenario is when there are no conditions, and the applicant is not intending to deceive [the company].
In this case, if he conceals some of his experience the concealing of which will not affect his work, and he is not clearly asked about it, then there is nothing wrong with that, so long as what is mentioned of his experience is true, and there is no lying or deceit.
And Allah knows best.