Gary Kertis, Developer in New York City, NY, United States
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Gary Kertis

Verified Expert  in Engineering

Software Developer

New York City, NY, United States
Toptal Member Since
February 7, 2022

Gary is a former Amazon engineer, currently teaching and freelancing. He specializes in adtech but is comfortable delivering projects in any sphere. He has over 15 years of experience as a developer. He has been a tech lead and a people manager, and he has designed and delivered greenfield projects and long-term system overhauls. At Amazon, Gary was a bar raiser and led more than 200 interviews and hiring panels.


TypeScript, Node.js, Ruby, Python, Amazon Web Services (AWS), Kubernetes...
Fullstack Academy
JavaScript, PostgreSQL, Node.js, React, MacOS, IntelliJ IDEA, Team Leadership
JavaScript, Java, React, Amazon Web Services (AWS), AWS Lambda...




Preferred Environment

Amazon Web Services (AWS), React, Node.js, Kubernetes, Terraform, Java, GitOps, Apache Kafka, Docker, Leadership

The most amazing...

...things I've built are large-scale systems. I am comfortable leading and delivering complex projects with a high degree of ambiguity.

Work Experience

Microservice Architect

2022 - PRESENT
  • Launched and scaled the company's internal appointment scheduling system, successfully migrating large swaths of the ecosystem away from the legacy monolith. Reduced schedule-related bugs and user complaints by 90%.
  • Owned critical developer tooling infrastructure and matured the team's engineering ops to align with tech industry standards. Developed internal user acceptance testing layer, shifting developers away from testing on release and production.
  • Authored internal design documents for overhauling DevOps and onboarding infrastructures. Created proof-of-concept for event-driven architecture.
  • Led interviews and engineering hiring panels for architect-level positions.
Technologies: TypeScript, Node.js, Ruby, Python, Amazon Web Services (AWS), Kubernetes, PostgreSQL, Apache Kafka, Team Leadership

Web Development Instructor

2021 - 2023
Fullstack Academy
  • Led coding Bootcamp lectures and workshops for cohorts of adult students. Cohort sizes ranged from 30-60 students. The material covered all aspects of modern full-stack web development, algorithms, and whiteboarding.
  • Worked one-on-one with students to enhance their understanding of the material. Offered social-emotional guidance for overcoming the rigors of the coding Bootcamp and avoiding impostor syndrome.
  • Prepared live-coding demos, graded assignments, and offered code reviews for group projects.
Technologies: JavaScript, PostgreSQL, Node.js, React, MacOS, IntelliJ IDEA, Team Leadership

Software Development Engineer II

2017 - 2021
  • Built and maintained a Squarespace-style WYSIWYG advertiser landing page creation tool. I scaled and hardened it for production. Ensured system reliability during peak periods like Black Friday and Cyber Monday events.
  • Led more than 200 interviews and acted as bar raiser, leading hiring panel discussions and socializing company culture. Formally mentored several developers directly in a one-to-one fashion.
  • Redesigned a creative management platform to reduce tech debt and allow federated development of innovative products. Worked closely with stakeholders from across the organization to build consensus and anticipate risk.
  • Built and maintained an incentive-based advertising service to facilitate promotional giveaways, tailored requirements as the product grew in popularity, and ensured ongoing security.
  • Managed projects through the entire development lifecycle, design, development, testing, deployment, operational metrics, and business intelligence.
  • Worked across the stack, building and scaling back-end services and responsive front-end UIs, and creating consumable APIs and reusable widgets.
Technologies: JavaScript, Java, React, Amazon Web Services (AWS), AWS Lambda, AWS CloudFormation, Node.js, SQL, NoSQL, Big Data, MacOS, IntelliJ IDEA, Amazon DynamoDB, Scalability, System Design, Team Leadership

Software Engineer

2014 - 2017
  • Worked to implement a private marketplace (PMP) platform in Angular and Spring, enabling digital publishers to safely auction their advertising inventory.
  • Onboarded publishers to the JavaScript header bidding program and provided access to new demand sources.
  • Analyzed publisher advertising data and offered recommendations to maximize advertising revenue.
Technologies: AngularJS, JavaScript, Spring MVC, Java, MacOS, IntelliJ IDEA, Amazon DynamoDB, Scalability, System Design, Header Bidding

Director of Revenue Operations

2011 - 2014
  • Built ad operations team. Hired, trained, and supervised a team of five.
  • Business owner of operational systems (DFP, DSM, Appnexus, Lotame), led ad server migration, negotiated terms.
  • Led a campaign execution and monetization of a non-guaranteed inventory.
Technologies: DFP API, JavaScript, MacOS, People Management

Manager of Advertising Operations

2010 - 2011
New York Media
  • Led the advertising operations department. Managed revenue forecasting, delivery, billing, and reconciliation.
  • Supervised the trafficking team. Served in an advisory capacity to the sales team, ensured rate compliance and inventory management, and offered creative insight into proposal processes.
  • Created and executed technically complex products and campaigns. This work was done closely with the internal development team and third-party vendors.
Technologies: JavaScript, DFP API, MacOS, People Management

Creative Authoring Platform

I redesigned and developed a full-stack creative management platform for a large-scale (FAANG) client, which unlocked federated development and increased time-to-market for various new products. The platform was distributed across several microservices and leveraged AWS heavily, with support for React, mobile, and OTT devices. It created a path to sunsetting a number of legacy systems that had grown unwieldy and lacked clear ownership.

Calendaring Microservice

I created, designed, deployed, and managed a NestJs-based microservice that received and processed high volumes of real-time data to keep customer calendars up to date and surface availability.


A web application to convert 8-bit sprite images to computer numerical control programming (CNC) instructions.

The front end was in React. It communicates with an API layer in Java, which activates a Rust service to perform the actual transformation using graph traversal algorithms.
2001 - 2005

Bachelor's Degree in Logic and Philosophy

University of Southern Mississippi - Hattiesburg, MS


React, Node.js, DFP API, Google Calendar API


IntelliJ IDEA, AWS CloudFormation, Terraform


JavaScript, Java, TypeScript, SQL, Rust, Ruby, Python


MacOS, AWS Lambda, Visual Studio Code (VS Code), Amazon Web Services (AWS), Docker, Kubernetes, Apache Kafka


Amazon DynamoDB, NoSQL, PostgreSQL, Datadog


Spring MVC, AngularJS, NestJS


Programming, Team Leadership, System Design, Scalability, Leadership, People Management, Big Data, GitOps, Header Bidding

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