Jonnie Bahr

Chicago

Summary

Senior Java Backend Engineer with 5+ years of experience designing and operating high-performance, distributed systems in high-traffic, revenue-critical environments. Deep expertise in Java, Spring Boot, and Spring Batch, with a strong focus on API-driven service design, performance optimization, and reliability. Proven leader of automation initiatives integrating LLM- and RAG-powered workflows directly into Java services, delivering measurable cost reductions and operational efficiency. Comfortable owning production systems end to end and building solutions that scale with business growth.

Overview

years of professional experience

Work History

Software Engineer II / Senior Software Engineer (Backend – Java)

Vivid Seats

Chicago, IL

05.2023 - Current

- Led development of Spring-based backend services supporting ~25k daily orders.
- Designed and owned a chatbot and automation platform saving ~$3M annually.
- Built LLM- and RAG-powered automation pipelines increasing throughput by 40%.
- Reduced SQL latency by 80%, migrated services from Java 8 to Java 17, and modernized batch processing.
- Mentored junior engineers and led backend design decisions.

Software Engineer

M&T Bank

Buffalo, NY

08.2020 - 05.2023

- Built Spring Boot APIs serving 1,000+ daily users with >99% uptime.
- Automated ETL pipelines processing 2M+ records.
- Optimized SQL and system performance, reducing latency by 40%.

Education

Bachelor of Science - Computer Sciences

University of Wisconsin, Madison

Madison, WI

05-2020

Skills

Java & Backend: Java, Spring Boot, Spring Batch, REST APIs, microservices, service-level design, concurrency, performance tuning
Architecture & Data: Distributed systems, event-driven design, ETL pipelines, SQL (MySQL, MS SQL), schema design, query optimization
Cloud & Reliability: AWS (EKS, SQS, SNS, S3, CloudWatch), Docker, Kubernetes, Datadog, autoscaling, incident response

Automation & DevOps: LLM/RAG workflows, Jenkins, Argo Workflows/CronWorkflows, CI/CD
Frontend (Working Knowledge): JSP, React, Angular, JavaScript, TypeScript
Product & Collaboration: Cross-functional delivery, Agile/Scrum, stakeholder alignment, roadmap execution

Platform & Infrastructure Impact (Supporting Java Services)

- Built and operated Java backend services at platform scale supporting high-volume partner workflows.
- Integrated LLM- and RAG-powered automation directly into Java services, enabling optimization loops and cost reduction.
- Applied observability (Datadog APM, metrics, logs) to drive latency reduction and capacity planning.
- Led scale-readiness efforts (autoscaling, alert tuning) to ensure application-layer reliability.

Timeline