  Academia and industry have developed several platforms to support the popular
privacy-preserving distributed learning method -- Federated Learning (FL).
However, these platforms are complex to use and require a deep understanding of
FL, which imposes high barriers to entry for beginners, limits the productivity
of researchers, and compromises deployment efficiency. In this paper, we
propose the first low-code FL platform, EasyFL, to enable users with various
levels of expertise to experiment and prototype FL applications with little
coding. We achieve this goal while ensuring great flexibility and extensibility
for customization by unifying simple API design, modular design, and granular
training flow abstraction. With only a few lines of code, EasyFL empowers them
with many out-of-the-box functionalities to accelerate experimentation and
deployment. These practical functionalities are heterogeneity simulation,
comprehensive tracking, distributed training optimization, and seamless
deployment. They are proposed based on challenges identified in the proposed FL
life cycle. Compared with other platforms, EasyFL not only requires just three
lines of code (at least 10x lesser) to build a vanilla FL application but also
incurs lower training overhead. Besides, our evaluations demonstrate that
EasyFL expedites distributed training by 1.5x. It also improves the efficiency
of deployment. We believe that EasyFL will increase the productivity of
researchers and democratize FL to wider audiences.
