[Route("{user}/{platform}/profile")]
    [HttpPut]
    public async Task UpdateProfile([ModelBinder]AppUser user, Platform platform, [FromBody] IProfile profile)

public class ProfileModelBinder : IModelBinder
{
    public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
    {
        object platformParameterFromQueryString;

        if (actionContext.RequestContext.RouteData.Values.TryGetValue("platform", out platformParameterFromQueryString))
        {
            Platform platformParameter;

            if (platformParameterFromQueryString == null || !Enum.TryParse<Platform>(platformParameterFromQueryString.ToString(), out platformParameter))
                throw new ArgumentException("platform parameter not found");

            if (platformParameter== Platform.Alpha)
            {
                var jsonContent = actionContext.Request.Content.ReadAsStringAsync().Result;

                bindingContext.Model = JsonConvert.DeserializeObject<AlphaProfile>(jsonContent);
            }
            else
            {
                throw new NotImplementedException();
            }
        }



        return (bindingContext.Model != null);
    }
}