AWS Step Functions / 2024

JSONata and Variables

I owned frontend validation for the JSONata and Variables launch, repaired 26 library parity tests, and wrote and ran the pre-launch load-test plan.

Definition-time validation

Step Functions was adding JSONata alongside JSONPath. I implemented QueryLanguage validation at both the state-machine and individual-state level so customers could adopt JSONata one state at a time.

I also built context-aware validation for the $states object. For example, a reference to a task result must be valid for the current state type and field. Invalid references now fail when the state machine is created or updated, with a diagnostic pointing to the expression.

Java library parity

I analyzed a baseline of 126 failing tests against the Java JSONata implementation and tracked expected behavior, root causes, and fixes. My two library changes repaired 26 of those tests.

The fixes covered number parsing, timestamps, formatting, and typed error codes. They replaced generic runtime exceptions with the errors defined by JSONata. Other engineers contributed additional fixes to the wider parity effort.

Launch preparation

I authored and executed the load-test plan before the re:Invent 2024 launch. The validation changes shipped behind feature flags, allowing them to be enabled independently.

I expanded shared test infrastructure and reviewed related changes during the launch. The work covered implementation, correctness analysis, and release preparation.

Technologies

Java · JSONata · Workflow validation · Language semantics · Load testing