ABOUT

Jeff Sylvan

Principal Software Engineer. Distributed systems, platform engineering, production ML, and AI infrastructure.

About me

I design distributed systems, developer platforms, and production ML and agentic AI services. My work has reduced deployment cycles from days to minutes, supported services at thousands of queries per second, and cut game infrastructure costs by 90%. I've shipped software for companies like CarGurus, HubSpot, and Vistaprint, and for startups including my own; the constant is scalable, reliable systems and a habit of making the engineers around me faster.

CogniCluster is my current independent engineering lab. PlotWarden is the orchestration system, and Black Skies is the distributed-systems proving ground and product it helps build. Most of the code is written through an agentic, spec-based workflow: best-in-class tooling where it exists, my own where it does not. The receipts start at the build ledger.

Available for full-time Principal and Staff-equivalent engineering roles in distributed systems, platform engineering, production ML, and AI infrastructure. Boston area or remote.

Work

Highlighted engineering work.

Four case studies from paid engineering roles: production ML, an enterprise delivery platform, a high-scale commerce rebuild, and multiplayer infrastructure economics.

Read the Work page

Now

What I'm working on now.

Live artifacts you can open right now; the receipts behind everything below.

Black Skies · the thesis the benchmark ledger PlotWarden CogniCluster

Career

FEB 2026 – PRESENT

Founding Engineer · CogniCluster LLC (company site)

Independent engineering company developing ambitious distributed systems and AI infrastructure. Current work includes Black Skies, designed for 10,000-player battles without time dilation, and PlotWarden, the durable orchestrator coordinating its parallel AI-assisted development.

Distributed Systems
Microservices
Java
C#/.NET
.NET
Go
RAG
SWIM Gossip
Epoch Fencing
H3
Redis Streams
Aurora Limitless
DynamoDB
PostgreSQL
Elasticsearch
gRPC
Kubernetes
EKS
AWS
Consistent Hashing
Event Sourcing
OpenTelemetry
Temporal
Playwright
AI Agents
MCP
Codex
Claude Code
Devin
Cursor
OpenRouter
Ubuntu
Incident Response & Postmortems
AI Evaluation & Regression Testing
AI Guardrails & Responsible AI
AI Security, IAM & Auditability
Developer Experience
Internal Developer Platforms
Platform Adoption
Infrastructure as Code
Terraform / OpenTofu
Docker
GitHub Actions
LLMOps
Model & Prompt Observability
Human-in-the-Loop Systems
MCP / A2A Security
Multi-Tenant Systems
Production Ownership
Technical Strategy
Cross-Functional Influence
Cost / Latency / Quality Optimization

2023 – 2026

Principal Software Engineer · CarGurus (company site)

Led the first non-data-science team to ship a production ML application with a full MLOps pipeline, highlighted to investors on an earnings call. ADRs and architecture reviews, monolith to services, and mentoring across backend teams.

Java
TypeScript
Microservices
AWS
SageMaker
PydanticAI
CrewAI
RAG
Kubernetes
Kafka
Flink
PySpark
Snowflake
scikit-learn
XGBoost
MongoDB
GraphQL
REST
SQL
Honeycomb
Puppeteer
MCP
Replit
Bolt.new
Windsurf
Cursor
Mentoring
Incident Response & Postmortems
AI Evaluation & Regression Testing
AI Guardrails & Responsible AI
Developer Experience
Internal Developer Platforms
Platform Adoption
Infrastructure as Code
Terraform / OpenTofu
Docker
Multi-Tenant Systems
Production Ownership
Technical Strategy
Cross-Functional Influence
Cost / Latency / Quality Optimization

2018 – 2023

Senior Software Engineer · First Republic Bank

Worked with the bank's CTO to modernize its technology infrastructure: built the continuous delivery pipeline that took releases from days to minutes, drove adoption across hundreds of engineers, and trained 50+ of the bank's VPs, directors, architects, and team leads on the practices behind it.

C#
.NET
TypeScript
Microservices
AWS
Kafka
Kubernetes
Istio
Helm
Jenkins
MSSQL
Clean Architecture
Domain-Driven Design
Mentoring
Internal Developer Platforms
Platform Adoption
Infrastructure as Code
Terraform / OpenTofu
Docker
Production Ownership
Technical Strategy
Cross-Functional Influence
Cost / Latency / Quality Optimization

2017 – 2018

Senior Software Engineer · HubSpot (company site)

Kafka-backed identity and user-data pipelines.

Java
Microservices
Kafka
MSSQL
OAuth
Data Pipelines

2015 – 2017

Lead Software Engineer · Cimpress (Vistaprint) (company site)

Found the scaling flaw in core commerce infrastructure that threatened EU sales, won cross-department buy-in, led the rebuild, and handed a junior team a platform that ran incident-free at thousands of queries per second.

C#
TypeScript
MSSQL
AWS
Monolith Decomposition
Composition over Inheritance
Microservices
REST
Caching
Infrastructure as Code
Terraform / OpenTofu
Docker
Multi-Tenant Systems
Production Ownership
Technical Strategy
Cross-Functional Influence
Cost / Latency / Quality Optimization

2012 – 2015

Founder and CTO · Apocoplay

Founded the studio, led a team of 20, and built a server-side engine for large-scale multiplayer games that cut server and development costs by 90%, saving customers hundreds of thousands of dollars annually.

C#
.NET
TypeScript
PHP
MySQL
Redis
Microservices
AWS
Azure
Linux Server Management
Angular
Event Streaming
Multiplayer Infrastructure
Internal Developer Platforms
Platform Adoption
Production Ownership
Technical Strategy
Cross-Functional Influence
Cost / Latency / Quality Optimization

1999 – 2012

Earlier roles · ASC Games · Allscripts · Council for Logistics Research · PRTM · QScend

Additional software engineering, infrastructure, logistics, and pre-release game work across the first decade of my career. Details on LinkedIn

Microservices
Production Ownership
Technical Strategy
Cross-Functional Influence
Cost / Latency / Quality Optimization

EDUCATION

Continual learner

A subset of the formal coursework, alongside continual self-directed study: University of Hartford, B.S. Computer Science · MIT IDSS Certificate in Data Science · MIT Certificate in Blockchain · MIT Start Smart, a course series in entrepreneurial studies · MIT Invest Smart, a course series on angel investing · Interview Kickstart, advanced professional development (2021–present): backend engineering and system design, machine learning, and applied agentic AI for software engineers · plus ongoing hands-on work in distributed systems, AI agents, platform engineering, load testing, and chaos testing.

Start with the impact case studies, the Black Skies architecture thesis, or the benchmark ledger. Send a note and I will respond quickly.

Contact

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