diff --git a/src/config.rs b/src/config.rs
index 33d8684..4dc15d4 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -66,7 +66,7 @@ mod tests {
 
    #[test]
    fn test_build_config_yaml() {
-      build_config_yaml("./src/testdata/config-kinesis-to-kafka.json".to_string());
-      build_config_yaml("./src/testdata/config-stdin-to-stdout.yaml".to_string());
+      build_config_yaml("./src/testdata/config-kinesis-to-kafka.json".to_string()).unwrap();
+      build_config_yaml("./src/testdata/config-stdin-to-stdout.yaml".to_string()).unwrap();
    }
 }
diff --git a/src/engine.rs b/src/engine.rs
index a64a17c..048514b 100644
--- a/src/engine.rs
+++ b/src/engine.rs
@@ -23,7 +23,7 @@ impl InputEngine for InputEngineStdin {
 }
 
 #[cfg(test)]
-mod test {
+mod test_input {
    use super::*;
 
    struct InputEngineTest {}
@@ -43,3 +43,43 @@ mod test {
       assert_eq!("hello world".to_string(), engine.get());
    }
 }
+
+pub trait OutputEngine {
+   fn put(&self, v: String);
+}
+
+pub fn build_output_engine(cfg: &Engine) -> Result<Box<dyn OutputEngine>, String> {
+   match cfg.name.as_str() {
+      "stdout" => return Ok(Box::new(OutputEngineStdout{})),
+      _ => return Err("unknown output engine name".to_string() + &cfg.name),
+   }
+}
+
+struct OutputEngineStdout {}
+
+impl OutputEngine for OutputEngineStdout {
+   fn put(&self, v: String) {
+      println!("{}", v);
+   }
+}
+
+#[cfg(test)]
+mod test_output {
+   use super::*;
+
+   struct OutputEngineTest {}
+   impl OutputEngine for OutputEngineTest {
+      fn put(&self, _v: String) {
+      }
+   }
+
+   #[test]
+   fn test_output_engine_impl() {
+      let output_engine_test = OutputEngineTest{};
+      _test_output_engine_impl(&output_engine_test);
+   }
+
+   fn _test_output_engine_impl(engine: &dyn OutputEngine) {
+      engine.put("teehee".to_string());
+   }
+}
diff --git a/src/main.rs b/src/main.rs
index c63dfc7..6189a58 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,6 +4,8 @@ mod engine;
 fn main() {
    let cfg = config::build_config().unwrap();
    let input_engine = engine::build_input_engine(&cfg.streams.input.engine);
+   let output_engine = engine::build_output_engine(&cfg.streams.output.engine);
    println!("{:?} => {}", cfg.streams.input.engine.name, input_engine.is_ok());
-   println!("{}", input_engine.unwrap().get());
+   println!("{:?} => {}", cfg.streams.output.engine.name, output_engine.is_ok());
+   output_engine.unwrap().put(input_engine.unwrap().get());
 }