The title is misleading. A company secretary is not a secretary in the everyday sense, and the role has nothing to do with administrative support. It is a statutory office, and Singapore law requires every company to fill it within six months of incorporation.
The person has to be a natural person ordinarily resident in Singapore. A company with only one director cannot have that director act as its own secretary, which is a rule sole founders tend to discover late.
The work itself is record keeping with legal weight. Statutory registers of directors, shareholders, and charges. The register of registrable controllers, which has to exist within thirty days of incorporation. Board and shareholder resolutions, written up properly and kept.
Then the filings. The annual return goes to ACRA within seven months of the financial year end. Changes to directors, addresses, share capital, and shareholdings each have their own deadlines, most counted in days rather than months.
The reason this matters is that your ACRA record is what other people read when they want to know what your company is. Banks read it during onboarding. Investors read it during due diligence. Buyers read it before an acquisition. If the record disagrees with reality, the conversation stops until it is fixed.
The failure mode is quiet. Nothing goes wrong for a year or two, because nobody is looking. Then a financing round begins, someone asks for the register of members, and it emerges that three share transfers were never recorded and two directors were appointed by email.
A good company secretary makes that scenario impossible, and you mostly notice them by the absence of problems. That is the job.