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I am a Senior Software Engineer with approximately 13 years of experience building reliable production applications across customer-facing web and native environments. My work spans REST/JSON APIs, React and TypeScript interfaces, cloud-hosted services, authentication, checkout, session management, and distributed systems.…

Johann Koeh

Software Engineer, Back-End Developer, Front-End Developer, +2

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I am a Senior Software Engineer with approximately 13 years of experience building reliable production applications across customer-facing web and native environments. My work spans REST/JSON APIs, React and TypeScript interfaces, cloud-hosted services, authentication, checkout, session management, and distributed systems.…

Available to hire

I am a Senior Software Engineer with approximately 13 years of experience building reliable production applications across customer-facing web and native environments. My work spans REST/JSON APIs, React and TypeScript interfaces, cloud-hosted services, authentication, checkout, session management, and distributed systems.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Intermediate

Intermediate

Language

English

Fluent

Work Experience

Senior Software Engineer at DoorDash

April 1, 2023 - Present

Builds DoorDash Storefront, a white-label commerce platform supporting branded ordering, checkout, and delivery across web and mobile. Developed secure REST APIs for mobile checkout, improved session management and cart-to-checkout flows, migrated checkout into a standalone repository, and co-developed authentication flows that reduced login errors by 94%. Built deep-linking and attribution functionality with real-time connectivity, improving user journeys by 31%.

Software Engineer at DoorDash

August 1, 2021 - April 1, 2023

Worked on DoorDash Storefront features involving onboarding, authentication, secure account-to-checkout integrations, and responsive web application components. Developed login and role-based access control flows using secure REST APIs, reduced frontend bundle size by 1.9 MB, eliminated approximately 1 million redundant checkout calls per day, created monitoring dashboards for devices and networks, and improved CI/CD release processes by reducing pull request turnaround from three days to one day.

Senior Software Engineer at Illumina

January 1, 2018 - July 1, 2021

Engineered customer tooling and backend services for distributed microservices environments using Docker, Kubernetes, Python, React, and Node.js. Built a React and TypeScript console for dashboards and user workflows, developed Kubernetes services to aggregate instrument utilization data, created Dockerized C# test automation for CI/CD, and monitored anomaly-detection pipelines with Node.js and Python dashboards to reduce troubleshooting time.

Software Engineer 2 at Illumina

May 1, 2016 - December 1, 2017

Developed automation for software releases and quality workflows, including API and UI testing, documentation tooling, and load-testing services. Improved maintainability and DevOps practices for backend changes, supported remote-node management, and contributed to reliable release and validation processes.

Software Test Engineer 2 at Illumina

September 1, 2013 - April 1, 2016

Performed black-box manual testing, API and UI testing, system integration testing, and end-to-end testing. Developed C# and TypeScript automation tests, modernized testing frameworks, created bash scripts for test environments and data setup, built a release documentation CLI that reduced recurring work to nearly zero, and contributed to Dockerized load testing hosted on Jenkins. Supported migration validation and agile testing strategy planning.