Tolaz Hewa
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Tolaz Hewa

Senior Software Engineer (Distributed Systems, AI/RAG)

Toronto, ON

Senior Engineer dedicated to technical excellence and ownership. 6+ years delivering complex backend infrastructure for regulated environments (FinTech, Social, Supply Chain). Experienced in driving engineering velocity through improved tooling, codegen, and rigorous testing standards. Passionate about shifting from governing AI applications to engineering the core Java-based search and retrieval machinery that powers them.

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Experience

Software Engineer

Robinhood

Nov 2024 - Present Toronto, ON
  • Built the centralized ML/Agent governance platform supporting the company's RAG applications. Designed model registries and retrieval-aware schema validation for LLM agents.
  • Standardized DB transaction patterns and resolved sequence overflow issues in high-scale services; delivered a centralized DB package with SLO alerts, resulting in zero on-call tickets for DB operations since rollout.
  • Implemented a cross-system Rules Engine and validation APIs (Go/Protobuf) to encode complex legal policy decisions, replacing manual reviews with deterministic backend logic.
  • Integrated LLM providers (OpenAI, Anthropic, Vertex) and vector/retrieval toolchains. Operationalized Braintrust ETL for continuous evaluation of hallucination, bias, and jailbreaks.
  • Authored a protobuf-based codegen framework (Go/Python) to centralize enums/tag maps, guaranteeing cross-language synchronization and eliminating schema drift across distributed services.
  • Led comprehensive refactors to raise deployment safety, increasing unit test coverage from ~10% to ~70% in critical backend paths.
Go Python Protobuf RAG LLM PostgreSQL Kubernetes

Software Engineer

Meta

Jun 2022 - Jun 2023 San Francisco, CA / Toronto, ON
  • Led the design and implementation of the Compliance Decision Engine. Unified jurisdiction resolution and policy evaluation across product surfaces to mitigate multibillion-dollar regulatory exposure.
  • Built audit-grade logging and metrics pipelines with end-to-end trace propagation, solving the "distributed needle in a haystack" problem for investigation teams.
  • Contributed to internal consoles (React/TypeScript) that surfaced policy insights, accelerating onboarding for product teams integrating with the compliance stack.
Distributed Systems React TypeScript Compliance Logging Metrics

Software Development Engineer

Amazon

Aug 2019 - Mar 2022 Toronto, ON
  • Designed and shipped high-throughput backend services using Java, DynamoDB (NoSQL), and event-driven architectures.
  • Founding engineer for Import Booking in SCOT (Supply Chain Optimization). Built core services and data pipelines from scratch, successfully onboarding 98+% of vendors over two years.
  • Partnered with product and TPMs to deliver resilient workflows handling global logistics data; implemented warehousing infra for analytics and decisioning.
Java DynamoDB AWS Event-Driven Architecture Data Pipelines

Tech Stack

Languages

Java Go Python SQL TypeScript C++ Rust

Backend Systems

Microservices gRPC / Protobuf Transactions Event-Driven Arch Rules Engines REST

Search & AI Infra

RAG Applications Vector Retrieval LLM Evals/Guardrails Model Registries Databricks / ETL

Databases / Infra

DynamoDB PostgreSQL MongoDB Kubernetes / Docker AWS (S3, SQS, SNS) Terraform / CDK

Frontend

React React Context Next.js TRPC

Education

B.S. in Computer Science (Honours)

Ryerson University

2014 - 2019 Toronto, ON

Data Science with Python

HarvardX

2023 San Francisco, CA