$("#grid").kendoGrid({
    context : _service,
    databound: _service.onDataBound,
    request : _otherService.onRequest // Ooops wrong context
}

Perhaps the workaround should be encouraged in this situation.

$("#grid").kendoGrid({
    context : _service,
    databound: _service.onDataBound
}

export class Service {
    onDataBound(e) {
       this.doSomething(); // this points at the grid instance so doSomething can't be called
    }

    doSomething() { }
}

// grid javascript

_service = new Service();

$("#grid").kendoGrid({
    ...
    databound: _service.onDataBound
    ...
}

The workaround so far is to add a base class to the service and register function calls slightly differently.

export abstract class ServiceBase { 
    bind(name) {
        return this[name].bind(this);
    }
}

export class Service extends ServiceBase { ... }

// Workaround grid code

$("#grid").kendoGrid({
    ...
    databound: _service.bind('onDataBound')
    ...
}

When calling like that the correct context is available for the this keyword and e.sender can be used to access the grid.