Singapore
I am a software engineer who is passionate about building products and aim to build systems in a robust and reliable manner. I believe in the importance of writing good tests, paying down tech debt, and understanding the trade-offs that come with every solution. I am also keen on knowledge sharing and I do so by documenting my learnings on my tech blog from time to time! Read them at https://karissekhoo.dev/posts While my core expertise lies in backend development with strong proficiency in Ruby and PostgreSQL, I am also well acquainted with frontend technologies such as React and Angular—enough to confidently contribute across the full stack when needed. Adaptability is one of my key strengths. I have a consistent track record of quickly picking up new technologies and frameworks, allowing me to deliver value fast.
Part of the Agent Platform global team, building solutions for service agents across all Delivery Hero brands—including foodpanda, Yemeksepeti, and foodora—to support customers, vendors, and riders.
- Worked on a supplier and content management backend service in Rails, managing multiple partner API integrations and asynchronous Sidekiq background jobs to coordinate order lifecycle updates and propagate status changes across internal services via webhooks. - Architected and scaled integration services for Ascenda’s reward content platform (gift cards, offers, merchandise), reducing supplier integration time by 50% through improved platform design. - Led end-to-end delivery of 3 global reward content integrations (gift cards, offers) with external partners—driving technical kickoffs, solution design (RFCs), development, and testing to expand Ascenda’s content catalog into various markets such as US, UK and Australia. - Improved system reliability and incident response to meet SLAs by implementing structured logging, Grafana metrics/alerting, and operational runbooks—enabling faster incident detection and resolution.
- Worked on a OAuth 2.0 and OIDC compliant authentication and IAM backend system enabling secure integration between internal services and external banking partners on Ascenda’s loyalty-as-a-service platform. Collaborated cross-functionally with engineering and product teams to design and implement authorization flows that streamlined bank onboarding. - Proposed and implemented an RFC to eliminate the manual domain whitelisting process for in-house Admin Panel authentication which was previously required for onboarding 10-15 new tenants monthly. This resulted in significant time savings and increased efficiency operationally, while ensuring scalability and security compliance of the system. - Actively involved in University Engagements as part of Ascenda's tech company branding by delivering tech presentation on Observability, and providing constructive feedback on the students’ projects to guide them on building robust systems. - Tech stack includes Hanami Ruby framework, and PostgreSQL, and frontend application using Angular.
- Build job recommendations and job search with Data Structures and Algorithms and Natural Language Processing techniques - Design and implement CI/CD pipeline using GitHub Actions for automated testing before deploying into development environment with AWS - Test and troubleshoot back-end running in AWS ECS Fargate and Elastic Cache based environment using AWS CloudWatch - Create technical documents (e.g. API design documents and developer guides)
- Work closely with a small team and participate building scalable back-end system for a mobile application using Node.js - Work with Docker based microservices and NoSQL database MongoDB - Design and build new REST APIs and modify existing APIs for key functionalities of the application - Unit testing for REST APIs - Troubleshoot back-end running in AWS ECS Fargate using AWS CloudWatch - Document technical design and solution of key functionalities
- Work with designers, journalists and developers to develop interactive website such as games and informative articles using vanilla JavaScript, SASS and HTML