Overtime, its not the language you code that matters. Application architecture, design, database skills etc do. All this comes from experience, building large applications. I understand you may not have the opportunity in your current company to build those. You can start building small projects in your personal time.

You are just 1.5 years in the industry. Taking such risks early is not advisable. Don't be impatient, keep learning. For example, you can redesign and build the 10 year old sites in a new language or in Java itself.