servicebase.cs

public abstract class ServiceBase
{
    private readonly HttpClient _httpClient;
    private readonly AsyncRetryPolicy _asyncRetryPolicy;
    public ServiceBase(HttpClient httpClient, RetryPolicyConfiguration retryPolicyConfiguration)
    {
        this._httpClient = httpClient;
        this._asyncRetryPolicy = this.CreatePolicy(retryPolicyConfiguration);
    }

    protected async Task<Result<T>> Get<T>(string url)
    {
        return await this._asyncRetryPolicy.ExecuteAsync(async () =>
        {
            var response = await this._httpClient.GetAsync(url);
            return await this.GetRequestContent<T>(response);
        });
    }

   {...}

    private AsyncRetryPolicy CreatePolicy(RetryPolicyConfiguration retryPolicyConfiguration)
        => Policy.Handle<Exception>(e => this.CanContinue(e) /*aqui você verifica, baseado na exception lançada, se deve continuar com o retry ou não */)
                 .WaitAndRetryAsync(retryCount: retryPolicyConfiguration.RetryCount,
                                    retryAttempt => TimeSpan.FromSeconds(retryAttempt * retryPolicyConfiguration.RetryAttemptFactor)
           );        
}

public class RetryPolicyConfiguration
{
    public static RetryPolicyConfiguration Default = new RetryPolicyConfiguration(3, 1);

    public int RetryCount { get; }
    public int RetryAttemptFactor { get; }

    public RetryPolicyConfiguration(int retryCount, int retryAttemptFactor)
    {
        this.RetryCount = retryCount;
        this.RetryAttemptFactor = retryAttemptFactor;
    }
}