February 24-26, 2027
Montreal, Canada
We Used Enums as Services — And It Worked
Java enums are usually introduced as a way to represent fixed sets of constants, but Effective Java also recommends a single-element enum as a safe way to implement a singleton. In this talk, I look at what happens when that pattern is used for small Java services, how it differs from classic singletons and DI-managed components, and where it starts to become a bad fit once state, dependencies, lifecycle, or testing requirements grow.
Hanieh Ershadbakhsh
Global relay
Hanieh Ershadbakhsh is a Vancouver-based Java developer who enjoys solving the hard problems behind financial systems—concurrency, messaging, failures, and reliability at scale. She has 7+ years of experience building payment and distributed systems processing millions of transactions. Hanieh has also taught Java as a Bootcamp Instructor and presented technical topics in academic and professional settings, including her research on risks in mobile payment applications.
