I’m a senior product-focused engineer who enjoys building user-facing systems with tight feedback loops. I like working close to real users, shipping features that get used immediately, and iterating quickly based on real-world usage rather than abstract requirements. My background is strongly rooted in JavaScript and frontend engineering, with extensive experience building web and hybrid mobile applications. I’ve worked across web apps, mobile apps, smartwatch apps, browser extensions, and other interactive surfaces where real people directly interact with the product. Much of my frontend work has been built with Angular and Ionic, particularly in environments where a single codebase supports multiple platforms. I’ve worked extensively with the Ionic framework in production and contributed a focused improvement back to the open-source project, making it the only open-source project I’ve contributed to directly. Over time, my role naturally expanded into full stack ownership. I’ve designed and built backend services, APIs, real-time systems, and data pipelines that support large-scale, user-facing products. I’m comfortable working across frontend architecture, backend logic, integrations, cloud infrastructure, and ongoing maintenance, especially in product teams where engineers are expected to own problems end to end. In recent years, my work has focused on AI-native and automation- heavy products. As part of a Y Combinator-backed company that evolved through a major pivot into a successful platform, I worked on systems supporting hundreds of GPT builders and hundreds of thousands of end users. The product has processed over five million user interactions and facilitated meaningful revenue flows to GPT builders. My involvement throughout was deeply hands-on, spanning product engineering, system design, and the practical application of AI to real workflows. I’m particularly interested in applied AI and automation where models, agents, and data systems are used to enhance real products, developer tools, or operational workflows. My focus is on pragmatic implementation, understanding tradeoffs, and shipping systems that work reliably in production rather than theoretical experimentation.

Celilsemi Sam Erkiner

I’m a senior product-focused engineer who enjoys building user-facing systems with tight feedback loops. I like working close to real users, shipping features that get used immediately, and iterating quickly based on real-world usage rather than abstract requirements. My background is strongly rooted in JavaScript and frontend engineering, with extensive experience building web and hybrid mobile applications. I’ve worked across web apps, mobile apps, smartwatch apps, browser extensions, and other interactive surfaces where real people directly interact with the product. Much of my frontend work has been built with Angular and Ionic, particularly in environments where a single codebase supports multiple platforms. I’ve worked extensively with the Ionic framework in production and contributed a focused improvement back to the open-source project, making it the only open-source project I’ve contributed to directly. Over time, my role naturally expanded into full stack ownership. I’ve designed and built backend services, APIs, real-time systems, and data pipelines that support large-scale, user-facing products. I’m comfortable working across frontend architecture, backend logic, integrations, cloud infrastructure, and ongoing maintenance, especially in product teams where engineers are expected to own problems end to end. In recent years, my work has focused on AI-native and automation- heavy products. As part of a Y Combinator-backed company that evolved through a major pivot into a successful platform, I worked on systems supporting hundreds of GPT builders and hundreds of thousands of end users. The product has processed over five million user interactions and facilitated meaningful revenue flows to GPT builders. My involvement throughout was deeply hands-on, spanning product engineering, system design, and the practical application of AI to real workflows. I’m particularly interested in applied AI and automation where models, agents, and data systems are used to enhance real products, developer tools, or operational workflows. My focus is on pragmatic implementation, understanding tradeoffs, and shipping systems that work reliably in production rather than theoretical experimentation.

Available to hire

I’m a senior product-focused engineer who enjoys building user-facing systems with tight feedback loops. I like working close to real users, shipping features that get used immediately, and iterating quickly based on real-world usage rather than abstract requirements. My background is strongly rooted in JavaScript and frontend engineering, with extensive experience building web and hybrid mobile applications. I’ve worked across web apps, mobile apps, smartwatch apps, browser extensions, and other interactive surfaces where real people directly interact with the product. Much of my frontend work has been built with Angular and Ionic, particularly in environments where a single codebase supports multiple platforms. I’ve worked extensively with the Ionic framework in production and contributed a focused improvement back to the open-source project, making it the only open-source project I’ve contributed to directly. Over time, my role naturally expanded into full stack ownership. I’ve designed and built backend services, APIs, real-time systems, and data pipelines that support large-scale, user-facing products. I’m comfortable working across frontend architecture, backend logic, integrations, cloud infrastructure, and ongoing maintenance, especially in product teams where engineers are expected to own problems end to end. In recent years, my work has focused on AI-native and automation- heavy products. As part of a Y Combinator-backed company that evolved through a major pivot into a successful platform, I worked on systems supporting hundreds of GPT builders and hundreds of thousands of end users. The product has processed over five million user interactions and facilitated meaningful revenue flows to GPT builders. My involvement throughout was deeply hands-on, spanning product engineering, system design, and the practical application of AI to real workflows.

I’m particularly interested in applied AI and automation where models, agents, and data systems are used to enhance real products, developer tools, or operational workflows. My focus is on pragmatic implementation, understanding tradeoffs, and shipping systems that work reliably in production rather than theoretical experimentation.

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Experience Level

Expert
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Language

English
Fluent

Work Experience

Chief Technology Officer at YC-backed marketplace for GPT monetization
February 1, 2021 - Present
Led end-to-end product delivery for a GPT monetization marketplace. Built and scaled a payments, entitlement, and access-control layer. Managed frontend, backend, and data engineering; shipped high-accuracy AI-enabled features; powered ~375k users and ~2,600 sellers; ~US$700k annual marketplace volume.
Lead Frontend Engineer at Crypto trading platform
March 1, 2018 - January 31, 2020
Led real-time frontend engineering for a crypto trading platform with web-based, mobile, and hybrid interfaces. Built live UI with WebSockets, RxJS, and modern frontend stack; delivered a scalable, responsive user experience.
Lead Frontend Engineer at VC-backed creator monetization startup
August 1, 2020 - July 31, 2021
Led core product end-to-end (web + backend); focused on usability, payments, and workflow automation in a small, high-trust team.
Full-Stack Engineer at Marketing agency
January 1, 2016 - January 1, 2018
First full-stack hire; helped expand into mobile and web products, built client mobile and web apps, and helped grow the engineering team to 4 people (including interns).
Chief Technology Officer at Top Road (YC W22)
February 1, 2021 - Present
Led and owned product engineering end-to-end for an AI-native platform supporting hundreds of GPT builders and end users. Built and evolved user-facing apps across web, desktop, and backend, maintaining a tight feedback loop with users and iterating rapidly based on real-world usage. Played a key engineering role through a major pivot, reshaping the product into a monetization and tooling layer for GPT-based products. Designed and implemented frontend architecture for web apps, browser extensions, and a desktop application. Built and maintained backend services, APIs, and data pipelines for authentication, payments, analytics, usage tracking, and large-scale event processing. Worked extensively with AI-driven workflows, LLM integrations, and automation systems to support GPT builders, monetization logic, and operational tooling.
Lead Product Engineer at Feather
August 1, 2020 - July 31, 2021
Led and built the core product for a VC-backed startup focused on enabling creators and instructors to host and monetize virtual events and digital content. Owned product engineering end-to-end, including a web application, backend services, and third-party integrations. Designed and implemented systems for content management, payments, and user workflows, remaining hands-on throughout development. Worked closely with early stakeholders to translate product ideas into shipped features while maintaining a strong focus on usability and reliability.
Lead Technical Consultant at Gennix Fund Pty Ltd
February 1, 2020 - April 1, 2021
Led full-stack product engineering across a multi-app ecosystem, including hybrid mobile applications (iOS and Android) and a desktop application. Owned frontend architecture and implementation using Angular and Ionic, focusing on reliability, performance, and shared architecture across platforms. Built and integrated backend services and workflows to support core investment operations, internal tooling, and data synchronization. Worked closely with founders and stakeholders to guide technical decisions, translate requirements into shipped features, and support the platform through active development.
Lead Frontend Engineer at Lex Exchange
March 1, 2018 - January 31, 2020
Led frontend engineering within a team of 12 for a large-scale exchange and trading platform. Built and maintained multiple user-facing applications across web, hybrid mobile, smartwatch, and messaging platforms (e.g., Fitbit app, Telegram chatbot). Worked closely with backend teams operating a microservices-based architecture to deliver real-time data, live updates, and high-throughput user workflows. Owned frontend architecture, performance, and reliability for complex, data-heavy interfaces used by a global audience.
Lead Software Engineer at DigiGround
November 1, 2016 - April 1, 2018
Led full-stack engineering in a small team building multiple client-facing web and hybrid mobile applications. Designed and delivered cross-platform mobile apps and supporting backend services, collaborating closely with clients and internal stakeholders. Shipped and maintained production applications, gaining broad experience across frontend, backend, and deployment in fast-moving environments.
Mobile Application Consultant at Justmop.com
January 1, 2016 - December 31, 2016
Engaged as a mobile application consultant to design, build, and maintain JustMop’s mobile apps. Built and shipped web-based mobile applications for iOS, Android, and Windows using Ionic (v1) and AngularJS. The apps reached over 10,000 downloads across iOS and Android platforms by early 2018, with ongoing maintenance and iterations through multiple releases.
Junior Frontend Developer at Pinnacle Yazılım
July 1, 2015 - September 1, 2016
Started professional career as a junior frontend developer, building web-based user interfaces. Built and maintained frontend components using JavaScript, HTML, and CSS, gaining foundational experience in production-grade codebases.

Education

Electrical and Electronics Engineering at Eskisehir Osmangazi University
January 11, 2030 - March 19, 2026
Bachelor of Business Administration (BBA) at Anadolu University
January 11, 2030 - March 19, 2026
Bachelor of Engineering (BE), Electrical and Electronics Engineering at Eskişehir Osmangazi Üniversitesi
January 1, 2010 - December 31, 2016
Bachelor of Business Administration (BBA), Business Administration at Anadolu University
January 1, 2009 - December 31, 2016
Entrepreneurship/Entrepreneurial Studies at Y Combinator
January 1, 2022 - March 1, 2022
High School Diploma, Physical Sciences at Eskişehir Fatih Anadolu Lisesi
January 1, 2005 - January 1, 2009

Qualifications

Add your qualifications or awards here.

Industry Experience

Software & Internet, Media & Entertainment, Professional Services