Alex Mercer

Lead AI & Full Stack Engineer

San Francisco, CA (Remote)
alex.mercer@nexus.dev
nexus.dev
github.com/alexmercer

Professional Summary

Engineering leader with 8+ years of experience architecting high-throughput backend systems and integrating generative AI into strict, multi-tenant enterprise environments. Specialized in decoupling legacy monoliths into scalable, observable microservices using Python, FastAPI, and Go. Proven track record of reducing infrastructure costs while improving system latency.

Experience

Lead AI Architecture

2024 — Present
Nexus Enterprise Solutions
  • Architected a multi-tenant RAG pipeline handling 50k+ daily queries, utilizing Qdrant payload filters to enforce strict row-level SQL permissions at the vector retrieval stage.
  • Designed a semantic caching layer with Redis, reducing OpenAI API costs by 45% and dropping P95 latency from 2.5s to 400ms for common query structures.
  • Implemented an internal Prompt Registry to version-control system prompts, enabling automated regression testing across multiple LLM endpoints.

Senior Backend Engineer

2021 — 2024
SkyCloud ERP Systems
  • Led a team of 4 in decoupling a 5-year-old Frappe (Python) monolith into domain-specific microservices using FastAPI and Apache Kafka.
  • Optimized monolithic PostgreSQL queries, introducing partial indexes and materialized views, which reduced dashboard load times from 8s to under 1s.
  • Built a custom syncing engine that reconciled offline mobile app data with the central ERP database, handling conflict resolution for 10,000+ daily warehouse transactions.

Full Stack Developer

2018 — 2021
DataFlow Analytics
  • Developed interactive financial dashboards using React and D3.js, consuming high-frequency data via WebSockets.
  • Migrated the primary REST API from Express.js to Go, achieving a 3x increase in throughput on identical hardware.

Technical Skills

Languages & FrameworksPython (FastAPI, Flask), TypeScript, React, Next.js, Go, Node.js, SQL.
Infrastructure & DevOpsDocker, Kubernetes (K3s), AWS (EC2, S3, RDS), GitHub Actions, Terraform, Linux.
Databases & StatePostgreSQL, Qdrant (Vector DB), Redis, MongoDB, MariaDB.
AI & LLM ToolingLangChain, LlamaIndex, OpenAI API, HuggingFace, Prompt Engineering.

Education

B.S. Computer Science

University of Technology • 2014 — 2018
Specialization in Distributed Systems

Certifications

  • AWS Certified Solutions Architect — Professional
  • CKAD — Certified Kubernetes Application Developer
  • DeepLearning.AI — Natural Language Processing Specialization