Jeffrey Sánchez
Fullstack & Go Engineer → AI Systems Architect
Distributed Systems · LLM Integration · MLOps
Turning infrastructure into intelligence
About
I initially started my programming journey in college by pitching into C. From there, I successively engaged in Qt/C++ ASP.NET/C# PHP/JS/HTML/CSS Web/Python etc. Across 10+ companies, a few of them transnationals, I mostly wrote server-side code in TypeScript Python Go while designing backend and full-stack as a systems engineer.
A dozen laps in, the stack has changed but the obsession hasn't. These days I'm scaling RPC services that serve large user bases at peak load with significant compute and latency savings, refactoring blocking calls into goroutine pipelines for meaningful throughput gains, and building AI agents that help engineers debug production systems before the next incident hits. One of them is an Oncall Agent that pairs LLMs with vector databases to correlate error logs with code locations and surface root causes automatically. Along the way I've led monolith-to-microservices migrations on AWS (FastAPI, Docker, K8s), rewritten dozens of stored procedures at a major bank to cut transaction time substantially, built ETL data lakes with Dagster feeding Power BI dashboards, and mentored engineers while setting up CI/CD and code review standards across teams.
For the moment, I primarily play with Go and Python. Once in a while, I drop down to Bash to get the job done when I have to.
Tech I think in
LanguagesGo · Python · C# · TypeScript
FrameworksFastAPI · React · React Native · Node.js · .NET MVC
AI / MLLLM APIs · RAG · Pipecat · TensorFlow · Vector DBs · Genesys Cloud AI
DatabasesPostgreSQL · MongoDB · Redis · SQL Server
InfraDocker · Kubernetes · AWS · CI/CD · Git · Bash
ObservabilityGrafana · Loki · Prometheus
ToolsgRPC · REST APIs · WebSockets · Linux · Bash scripting
The next chapter I'm actively building
- 2026 LLM APIs + Cloud-native AI systems
- 2027 MLOps · AI Security · Autonomous Agents
- 2028 Lead hybrid human-AI engineering teams
- 2029+ AI-First Systems Architect
The engineers who will matter most in the next 5 years aren't the ones who write the most code, they're the ones who architect systems that are fast, resilient, and intelligent. That's the engineer I'm becoming.
Experience
- Optimized core RPC services handling 2.9M peak QPS, achieving 50% compute resource savings and 30% latency reduction, conducted thorough staging/production testing and traffic diversion.
- Improved system throughput by ~35% by refactoring synchronous blocking calls into concurrent goroutine pipelines.
- Enhanced on call efficiency for Wallet services by developing AI driven analysers and auto conclusion features in the Oncall Agent, used Golang, LLMs, and vector databases to rank relevant events, correlate error logs with code locations, and suggest root causes, reducing engineers' on call burden.
- Boosted data processing throughput 3× by designing parallel Python pipelines that extracted, transformed, and loaded high-volume operational data into Azure Data Lake, cutting nightly batch windows from hours to minutes.
- Standardized the development framework and architecture, contributing to the core of new.arajet.com and establishing reusable patterns (CI/CD, code review, branching) that increased team velocity by 25%.
- Mentored six developers on clean code, test automation, and Azure DevOps best practices, accelerating their onboarding and fostering a culture of shared ownership and continuous integration.
- GNS – AI Consultant: Designed full observability stack with Grafana, Loki and Prometheus, architected AI agent orchestration services with Python/FastAPI for real‑time intent detection with Pipecat.
- CRECER LAB : Led backend architecture design for core product features focused on performance and scalability. Mentored junior developers, established code review standards and CI/CD workflows.
- ANTILLEAN SOFTWARE : Led migration from legacy monoliths to microservices using FastAPI/Alembic, spearheaded AWS deployments. Managed PostgreSQL migrations and centralised log management with MongoDB. Enhanced UI design and performance across web applications.
- Led migration from AngularJS to Angular 12+, refactoring legacy components and cutting UI bundle size by 40%, which accelerated page loads and improved developer productivity.
- Enhanced Ionic mobile app UX with RxJS and built Jasmine/Protractor test suites, raising code coverage from 45% to 85% and catching regressions early.
- Implemented XSS/CSRF security hardening across the app and optimized C#/.NET SQL stored procedures, reducing average response time by 30% for order management.
- Led development of the API to AMT Data Lake an open source ETL pipeline that extracts all Ed Fi ODS API data into JSON and Parquet, shaped to match the Analytics Middle Tier for Power BI consumption.
- Orchestrated parallel data ingestion with Dagster, leveraging configurable multi CPU processing for high throughput API pagination.
- Implemented descriptor mapping engine to normalise Ed Fi ODS enumeration variability across installations, enabling consistent AMT view filtering.
- Delivered document management and billing modules with C#, .NET MVC, and Angular, serving 200+ users and cutting paperwork time by 60%.
- Managed full lifecycle delivery, translating business requirements into technical specs and ensuring on-time releases through direct stakeholder collaboration.
- Wrote clean, testable code, integrated unit/UI tests cutting defects by 40%, and optimized SQL Server stored procedures, speeding reports by 50%.
- Led the integration of a physical point-of-sale system with the Odoo ERP backend, building a GraphQL API layer that synchronized inventory, sales, and customer data in near real time, reducing manual data entry errors by 70%.
- Developed real-time dashboards and notification features using React, Node.js, and Redis Pub/Sub, enabling store managers to monitor sales performance and stock levels instantly across multiple locations.
- Designed and implemented a comprehensive test suite with Pytest, achieving over 90% backend code coverage and establishing a continuous integration pipeline that reduced post-deployment issues by 50%.
- Rewrote 30+ stored procedures, functions, and jobs cutting transaction time ~45%, migrated apps to async/await.
- Automated processes from application layer to server, significantly improving data indexing performance.
- Drove team adoption of modern .NET patterns and async/await across the codebase.
- Built internal government applications in C#/.NET and WinForms that automated financial control and auditing workflows, replacing spreadsheet-based processes and reducing month-end reconciliation time by 30%.
- Wrote and optimised SQL Server stored procedures for complex reporting modules, tuning indexes and query plans that accelerated report generation from minutes to under 10 seconds for millions of records.
- Participated in full lifecycle development from requirements gathering to deployment, collaborating with senior auditors to ensure the applications met legal and regulatory standards for public sector accountability.
Education
Bachelor of Engineering - BE, Systems Engineering
Universidad Nacional Pedro Henríquez Ureña (UNPHU)
Associate Degree - AD, Software Development, Computer Programming
ITLA · Santo Domingo, DO
Certifications