With traffic profiles where requests arrive in at periodic intervals, and a low total amount of requests, serverless architecture seems to be a great architecture in terms of cost, speed of delivery and effort. Thus, Lambda is probably the way to go if our application has sufficiently large periods of inactivity. Once the break-even point is reached, when EC2 is more cost-effective than Lambda, the cost difference grows rapidly, making Lambda less and less attractive in terms of cost. Thus, it is of great importance to know if the expected amount of traffic will be around the break-even point. Be aware of the CPU throttling you will get with the smaller memory flavors of Lambda. If your code is CPU-bound, choosing the smaller memory flavors might not be an option, since execution times, and thus latency, might grow beyond your requirements. On the other hand, if your code is I/O bound, the CPU throttling might not affect you significantly. Break-even point (if there is one, that is) strongly depends on the application itself. Without measuring the target application code, knowing the intended usage of the service, the SLA and the capabilities of the team in charge of building the application it is almost impossible to know for sure which service, Lambda or EC2, is more convenient.