UPSIDER Sponsors "TSKaigi 2026" as Platinum Sponsor; Three Engineers to Present Technical Sessions

UPSIDER, Inc. (CEO: Toru Miyagi; Headquarters: Minato-ku, Tokyo) is pleased to announce its participation as a Platinum Sponsor for "TSKaigi 2026," held on May 22 (Fri) and 23 (Sat), 2026. Additionally, three engineers from the company have been selected to present technical sessions.

TSKaigi is one of Japan's largest technical conferences dedicated to TypeScript. For the 2026 event, proposals from Yusuke Izumi (VPoE), Tatsuhiko Mitsui, and Shotaro Nakada were accepted.

### Session Overview

1. **Type Safety Across Multiple Products via TypeSpec: Implementing 'Type Contracts' through Schema Sharing** This session introduces a case study of building an automated generation pipeline for Zod, API clients, and MSW mocks using TypeSpec as a foundation for 'Type Contracts.' It shares insights into mechanisms for detecting interface changes at compile time. - Time: May 22, 16:50–17:00 - Speaker: Tatsuhiko Mitsui (Engineering Manager)

2. **Do TypeScript Types Reach AI? — The Disconnect Between IDEs and AI Coding Tools** An investigation into tools like Claude Code, Cursor, GitHub Copilot, and Gemini. This session organizes what information reaches AI and compares three design philosophies for LSP. - Time: May 22, 17:00–17:10 - Speaker: Shotaro Nakada (Software Engineer)

3. **Mastering 400+ Data Points with Types — The Flexibility and Cohesion of TypeScript in UPSIDER's Credit Engine** Explains how to control over 400 data points using types in a credit engine built with Next.js/TypeScript. The session reveals strategies for integrating frontend and backend with a single interface. - Time: May 23, 11:10–11:40 - Speaker: Yusuke Izumi (VP of Engineering)

### Exhibition Information UPSIDER will host a booth in the venue foyer throughout the event. Visitors can enjoy interactive content related to TypeScript and receive original novelty items.

### Speaker Profiles - **Tatsuhiko Mitsui**: Engineering Manager. Previously led web development at CureApp and works at Works Applications. Now leading the platform development at UPSIDER. - **Shotaro Nakada**: Software Engineer. Previously a lead engineer at Nature Innovation Group. Currently focused on card infrastructure platform development at UPSIDER. - **Yusuke Izumi**: VP of Engineering. Previously a lead engineer at DeNA and Director/CTO at Raksul. Holds CFA certification and possesses deep expertise in both finance and technology.