How do I perform weighted loss in multiple outputs on a same model in Tensorflow?
As I understand it, you want to have a model trained on multiple "tasks". If so, this is what it could look like:

input_data = &lt;your input sequence input&gt;
output_data = &lt;array of size (N, 3)&gt;

out1_weight, out2_weight, out3_weight = &lt;your weights for each output to adjust loss contribution&gt;

input = Input()
simple_rnn = SimpleRNN()(input)

# Define the three outputs
out1 = Dense(1)(simple_rnn)
out2 = Dense(1)(simple_rnn)
out3 = Dense(1)(simple_rnn)

model = Model(inputs=[input], outputs=[out1, out2, out3], loss_weights=[out1_weight, out2_weight, out3_weight])

model.compile(&lt;whatever params&gt;)
model.fit(input_data, [output_data[:, 0], output_data[:, 1], output_data[:, 2]])