Point your AI agent at freehire and let it find you a job. A CLI and an MCP server over the whole job API — no browser.
Build and integrate automated mobile-app security tools (anti-tampering, obfuscation, crypto, SAST/DAST) into CI/CD to harden Toss’s Android and iOS apps.
Performs penetration testing and vulnerability assessments on Toss’s financial services (web/mobile), researches new attack methods, and improves security for infrastructure and DevOps environments.
A Security Researcher performs simulated hacking (APT attacks) and infrastructure diagnostics to proactively identify and mitigate vulnerabilities across Toss’s financial systems, collaborating closely with engineering teams to enhance security while balancing usability.
Build and maintain Toss’s security platform, designing IAM and auth gateways, and creating pre-deployment defenses to block vulnerabilities and malicious code before they reach production.
Builds and migrates Toss Bank’s lending backend systems, transitioning legacy monolithic core-banking code to Kotlin/Spring microservices while ensuring zero-tolerance accuracy for loan calculations and regulatory compliance.
Builds and refactors core banking systems (accounting layer) using Java/Kotlin and Spring, migrating legacy monoliths to scalable microservices for Toss Bank’s digital finance platform.
Develops and maintains payment systems, focusing on scalability and reliability. Core technologies include Java, Kotlin, Spring, Redis, Kafka, and MySQL.
Builds and operates scalable backend services for Toss’s offline payment platform using Java/Kotlin, Spring, Kafka, and Kubernetes.
Builds and operates core commerce systems (search, recommendations, orders, payments, ads) for Toss Shopping, a fast-growing B2C marketplace, using Kotlin/Spring and distributed data stacks.
Builds and operates scalable backend systems for a Korean fintech super-app’s financial marketplace, handling loans, cards, insurance, and accounts while integrating AI-driven automation.
Develops and optimizes high-performance real-time trading platforms (e.g., stock market data feeds) for Toss Securities, designing scalable architectures for APIs/WebSockets, low-latency event processing, and inter-institution communication using Go, Kotlin/Spring, and Kafka.
Builds and operates high-availability platform services for Toss Bank, including messaging, API gateways, monitoring, and caching, using Kotlin/Java and Spring ecosystems.
Builds shared backend services and frameworks in Java/Kotlin with Spring to help teams launch and scale securities services efficiently.
Build and maintain server-side components for Toss Securities using Java/Kotlin, Spring, Redis, Kafka, and Kubernetes, focusing on high-traffic trading systems and real-time data processing.
Builds and maintains the backend for Toss’s consumer-facing apps (payments, shopping, ads, etc.) using Kotlin, Spring, and distributed systems at scale.
Builds and scales server systems for Toss Income, a fintech service simplifying tax refunds and income management using Kotlin, Spring, and AWS.
Designs and develops high-availability, scalable server systems for Toss’s offline payment solutions, focusing on system architecture, real-time traffic handling, and end-to-end service reliability using Java/Kotlin, Spring, Kafka, and cloud-native tools.
Builds and maintains scalable, secure banking services using Kotlin/Java and Spring, focusing on high-traffic systems and innovative fintech products in a collaborative squad model.
Builds and maintains backend services for Toss’s fintech platform, focusing on scalability and reliability.
Builds and operates resilient payment infrastructure, focusing on stability, scalability, and low latency using Java, Kubernetes, and observability tools.
We couldn't check your fit for this role — add a CV to your profile to see it next time.