Aldert trained in civil law. After a brief career in administrative law and as a corporate lawyer, he became an attorney in 2000. His particular areas of expertise include professional liability, directors’ liability and contractual liability. He also handles disciplinary cases for and against solicitors, civil-law notaries and tax specialists.
In April 2024, Aldert completed the pension law course at VU University Amsterdam, earning him the title Certified Pension Lawyer. He has handled pension cases for employees, employers and pension funds for many years, including in the areas of pension entitlements, liability for contributions and the scope and exemption from mandatory participation.