He advises clients on a broad range of both contentious and non-contentious employment matters. He provides strategic advice and practical solutions to clients on matters including executive compensation and departures, compliance, regulatory employment law, cross-border HR projects, (European) works council matters, transfer of undertaking, contingent labour and collective labour agreement.

Arnold regularly teaches (post-)graduate courses on a variety of employment law aspects. He is member of the editorial board of the employment journal Tijdschrift Recht en Arbeid ("Law and Labour" ).

In 2014, Arnold was seconded to a Silicon Valley firm, focusing on incentive schemes and executive compensation and benefits for large technology companies.

Prior to joining the firm in 2005, Arnold worked for the International Labour Organization in Geneva, Switzerland, providing advisory work on fundamental labour standards