Hanieh Ershadbakhsh
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.
Sessions Montréal 2027
The Request Was Signed. Why Was It Still Unsafe?
Session en Anglais - Intermédiaire
In our wallet, third-party services received digitally signed requests, so it was easy to assume that a valid signature meant the request was safe. It wasn’t. A signed request could still be replayed, retried after a timeout, arrive with clock skew, or leave important fields outside the signature. This talk looks at those failure cases and the practical use of nonces, idempotency, key rotation, and replay protection to handle them safely.
We Used Enums as Services — And It Worked
Session en Anglais - Intermédiaire
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.
