Karl Cassel

Backend & Infrastructure Engineer · SRE · San Francisco, CA

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Summary

Engineer with 7+ years building internet-scale backend systems and distributed infrastructure for high-throughput, low-latency applications. Expert in architecting production-ready services from requirements through global deployment, with deep experience in Go, Python, and cloud-native architectures on AWS and GCP. Proven technical leader driving cross-team initiatives, mentoring engineering teams, and delivering reliable backend systems processing billions of requests daily. Strong collaboration across engineering, product, design, and research teams to translate complex requirements into scalable solutions.

Core Skills

Languages

Go · Python · Java · KCL/Jsonnet

AI / LLM

LLM integrations & automation · Agentic workflows · MCP servers · Temporal durable execution · RAG · Vector search · Structured extraction

Cloud

AWS (EC2, ECS, Lambda, RDS, DynamoDB, CloudWatch) · GCP (GKE, BigQuery, Cloud Functions) · Azure

Infrastructure

Terraform · Ansible · CloudFormation · Infrastructure-as-code

Databases

PostgreSQL · BigQuery · DynamoDB · RDS · SQL

Containers & Orchestration

Kubernetes · Docker · Helm · ArgoCD · Service mesh

Streaming & Data

Kafka · Apache Flink · Event-driven architectures · Real-time analytics

Observability & CI/CD

Grafana · Prometheus · DataDog · Distributed tracing · GitHub Actions · Jenkins · GitLab CI

Experience

Senior Software Engineer Jun 2025 – Present
Unity · San Francisco, CA
  • Architected large-scale backend data pipelines processing billions of daily events using Kafka, BigQuery, and event-driven architectures, supporting ML training and real-time analytics
  • Built high-throughput, low-latency backend services in Go and Python handling sub-second response times at internet scale with 99.9%+ availability
  • Designed Kafka monitoring infrastructure including custom Grafana dashboards for tiered storage cache metrics, performance monitoring, and automated alerting
  • Developed CI/CD automation tooling using GitHub Actions and ArgoCD, reducing deployment time by 40% while maintaining zero-downtime deployments
  • Built MCP (Model Context Protocol) servers on Temporal durable execution to automate infrastructure documentation across the Ads organization, integrating LLMs to parse, classify, and summarize change updates from KCL/Jsonnet infrastructure repositories
  • Helped scale production PostgreSQL databases supporting high-throughput backend services
Senior Software Engineer Dec 2021 – Apr 2025
Salesforce · San Francisco, CA
  • Led cross-functional infrastructure standardization initiative, architecting unified Terraform CI/CD pipelines across 5+ engineering teams — improving developer velocity and deployment consistency
  • Developed and maintained production backend services in Go: RESTful APIs, microservices, and distributed system components for MuleSoft's platform infrastructure
  • Designed backend infrastructure for database and storage systems, achieving 90% reduction in database-related incidents via automated monitoring and failover
  • Established infrastructure quality gates, security controls, and governance frameworks — reducing deployment errors by 30% and ensuring enterprise security compliance
  • Coordinated complex multi-environment Kubernetes deployments across commercial and government cloud infrastructure, collaborating with compliance teams on regulatory requirements
Cloud Engineer Jul 2018 – Aug 2021
JUUL Labs · San Francisco, CA
  • Built identity and access integrations between Workday and internal systems, syncing user identities and single sign-on (SSO) so employee records drove downstream account provisioning across IT services
  • Automated access-request routing so team approvals surface directly in Slack the moment access is requested, eliminating manually created IT access tickets
  • Designed onboarding/offboarding automation off Workday HR events, provisioning accounts on hire and deprovisioning on exit to close security gaps from stale accounts
  • Synced employee and org data from Workday into internal tools, maintaining a reliable source of truth for access, reporting, and downstream automation

Leadership & Mentorship

Engineering Mentor Sep 2025 – Present
BobaTalks & Hack the Hood · San Francisco, CA
  • Providing technical mentorship and career guidance to early-career engineers and students on software development best practices, system design, and professional development
People Leadership Across roles
Unity · Salesforce · JUUL Labs
  • Technical interviewer for engineering candidates (JUUL Labs)
  • Onboarding buddy for new engineers at Unity, Salesforce, and JUUL Labs
  • Wrote peer feedback for promotion packets and performance review cycles
  • Named technical lead for the Salesforce infrastructure standardization initiative — roadmap, design reviews, and work allocation across 5+ teams

Education

Bachelor of Arts, Computer Science Jun 2017
University of California, Santa Cruz

Certifications