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Applied AI & Backend Engineering

Preauth / Victoria

Production voice and text AI, evaluation and observability

Production · AI Engineer · Aug 2025–PresentManuel Alvarez

Overview

At Preauth, I build production workflows for Victoria, a WhatsApp assistant with voice and text. My work spans Python and LangChain agents, structured extraction, tool calling, conversation evaluation and the operational tooling needed to investigate failures.

Reporting and evaluation

I built and deployed a scheduled AWS reporting pipeline that combines operational metrics with sampled LLM evaluations. Lambda, EventBridge, Bedrock, DynamoDB and S3 support report generation, durable cost controls and duplicate-send protection.

The evaluation workflow uses strict structured outputs, source-evidence validation, reproducible sampling and explicit abstention when customer feedback is insufficient. This makes the findings easier to inspect and act on.

Real-time voice observability

I instrumented calls with LangSmith and fixed tracing issues involving asynchronous transcript ordering, tool execution, session renewal and shutdown, with regression coverage. These contributions sit within the team's broader voice platform.

Engineering focus

Employer code and customer conversations remain private. This case study describes my contributions without exposing internal data.

Technologies

PythonLangChainLangSmithOpikSQLAWS LambdaBedrockDynamoDBEventBridge