Armed with these principles, we hope the course will give a fresh perspective to design software systems. It might be over-engineering to get all this on day zero. But some are really important from day 0 like eliminating single points of failure, making scalable services by just increasing replicas. As a bottleneck is reached, we can split code by services, shard data to scale. As the organization matures, bringing in chaos engineering to measure how systems react to failure will help in designing robust software systems.