In general, if we are talking about bespoke (custom) web application development, the most common options are Java, PHP, and JavaScript. But to choose a programming language is just one step out of many. Everything becomes easier in case you decide to outsource the bespoke web app development services. The reason is simple - the professionals with tons of relevant experience will select the stack of needed technologies, which will suit best for the project and can cover all business requirements.
Bespoke web app development services nowadays is a flexible unit, using a multi-lingual approach. Its advantages are clear and transparent because it allows for increased velocity along with flexibility. Talking about our stack, we should point out such technologies as React.js, Angular.js, Vue.js, PostgreSQL, Python, MongoDB, Node.js, etc.