  Thanks to the latest advances in containerization, the serverless edge
computing model is becoming close to reality. Serverless at the edge is
expected to enable low latency applications with fast autoscaling mechanisms,
all running on heterogeneous and resource-constrained devices. In this work, we
engineer and experimentally benchmark a serverless edge computing system
architecture. We deploy a decentralized edge computing platform for serverless
applications providing processing, storage, and communication capabilities
using only open-source software, running over heterogeneous resources (e.g.,
virtual machines, Raspberry Pis, or bare metal servers, etc). To achieve that,
we provision an overlay-network based on Nebula network agnostic technology,
running over private or public networks, and use K3s to provide hardware
abstraction. We benchmark the system in terms of response times, throughput and
scalability using different hardware devices connected through the public
Internet. The results show that while serverless is feasible on heterogeneous
devices showing a good performance on constrained devices, such as Raspberry
Pis, the lack of support when determining computational power and network
characterization leaves much room for improvement in edge environments.
