Senior Web Engineer II - Platform

# Senior Web Engineer II
- Platform Ajaib Indonesia Full  time

Remote

Apply by Jan 9, 2027## About the role Founded to transform retail finance, Ajaib Group is an Indonesian fintech unicorn breaking barriers to financial access. Having recently secured a $270M Series C—the single largest funding round in Southeast Asia over the past four years—we are backed by premier global investors including Y Combinator, Ribbit Capital, Soft Bank, and SBI Holdings. To build world-class products, we assemble world-class talent.

Supported by our fully remote work arrangement, our team spans Eastern Europe, the Middle East, India, and Southeast Asia, allowing you to work with brilliant engineers and builders from around the globe from wherever you are. We operate with an impact-driven purpose where everyone is the owner of our customers' satisfaction. Driven by a growth mindset and a fierce will to win, we refuse to settle and constantly push engineering boundaries.

Role Overview As a Senior Web Engineer II in the Platform team, you build the web foundations that every Ajaib product team builds on: the design system and component library, shared packages, sign-in and session handling in the browser, and the build and release tooling. You own these foundations from design to production, treat other engineers as your customers, and help the engineers around you do better work.

Design, build and maintain shared web foundations: component library, design system, shared packages and the application shell.

Own features end to end: technical design, implementation, testing, release and support for the teams that use them. Keep shared packages stable: clear APIs, semantic versioning, change logs, migration guides and safe deprecation. Build accessible, themeable, well-documented components that product teams can adopt without custom work.

Build and improve secure sign-in, session and token handling on the web, working with backend and Security teams. Improve build speed, CI/CD pipelines, monorepo tooling and release automation for all web teams. Set and measure performance budgets and quality standards, such as Core Web Vitals, bundle size and accessibility checks.

Write maintainable, well-tested code and give thoughtful code reviews. Investigate production issues from error monitoring and feedback from product teams, and ship lasting fixes. Mentor mid-level engineers and share good web practices across teams.

Own the integration of our centralized identity platform (OAuth2/OIDC) into all web properties, ensuring zero-trust session management and protecting against modern web vulnerabilities. Establish and enforce company-wide frontend instrumentation standards. Build the core telemetry packages (logging, tracing, error boundaries) that product teams use to monitor their apps in production.### Requirements

Education:

Bachelor's degree in Computer Science or equivalent practical experience.

Experience:

5+ years of professional web engineering, including building shared libraries, design systems or tooling used by several teams. Languages & Frameworks:
Strong in Type Script and JavaScript; deep experience with React and a modern framework such as (deep knowledge in App Router / Pages Router is a must); strong component design.

Architecture & Tooling:

Experience with monorepos, bundlers, package publishing and build performance. Quality:
Solid experience with unit, integration, visual and end-to-end testing, CI/CD and error monitoring. Performance & Security:
Strong in browser performance profiling, accessibility and web security, including authentication on the web.

Deep understanding of browser mechanics, HTTP headers (CSP, CORS), cookie security policies, and token life cycles. Mindset:
Ownership mindset, clear…