Open to relocation · Europe, Australia, Singapore, US
Hi, I'm Khotib —
Senior Frontend Engineer
Senior Frontend Engineer with 7+ years of software engineering experience, including 5+ years building large-scale React and TypeScript applications at Traveloka and Tokopedia. Owns frontend architecture end to end, relentless on Core Web Vitals, and pixel-perfect on UI.
{ "name": "Muhammad Khotib", "focus": "React, TypeScript, Web Performance", "location": "Bogor, Indonesia", "relocation": "Europe, Australia, Singapore, US", "experience": "7+ yrs (5+ yrs React & TS)" }
Engineering for speed, at scale
Owning frontend architecture end to end — from config-driven, A/B-test-ready platforms and internal page builders to relentless Core Web Vitals optimization.
Senior Frontend Engineer with 7+ years of software engineering experience, including 5+ years building large-scale React and TypeScript applications at Traveloka and Tokopedia. Owns frontend architecture end to end: designed a config-driven, A/B-test-ready widget platform for Traveloka's SEO and ad landing pages, and built an internal page builder at Tokopedia that lets non-engineers ship CRUD pages.
Experienced with feature flagging and A/B testing in production, NestJS backends, React Native, and AI-assisted development with Claude Code. Pixel-perfect on UI, relentless on Core Web Vitals, and a mentor who shortens new-joiner ramp-up. Strong written and spoken English.
- 2015Started B.Sc. in Information Systems
Began studying Information Systems at Institut Teknologi Sepuluh Nopember (ITS), Surabaya.
- 2019Graduated & Joined the Industry
Graduated from ITS and started as a Full Stack Software Engineer at PT. Solusi Pembayaran Elektronik, implementing modular NestJS microservices and delivering 10+ client projects on tight timelines.
- 2021Moved into E-commerce at Scale
Joined Tokopedia on Tokopedia Salam (200M+ audience), rebuilding the Al-Quran reader with list virtualization (FID 360ms → 90ms) and creating an internal CRUD page builder for non-engineers.
- 2024Senior Web Software Engineer at Traveloka
Architected a config-driven SEO & ad landing page platform, shipped cross-platform React Native booking widgets, drove Core Web Vitals & >99% SLO, and built multi-agent Claude Code workflows.
Where I've made an impact
Measurable outcomes from live production systems, across three engineering teams.
- Architected a config-driven frontend platform for SEO and ad landing pages. Designed a master widget system where A/B test configuration decides which widgets render, in what order, and with which origin/destination content for each country and locale. Product teams run layout experiments without engineering changes.
- Built React Native booking-page widgets rendered as iOS, Android and web components from one codebase, and ran A/B experiments on them to measure their effect on cross-sell.
- Run feature flagging and A/B testing as a daily practice: enable or disable features by country or currency, and promote any flagged feature into an experiment. Ship through partial merges behind flags instead of long-running branches, so many engineers can work in the same repository safely.
- Improved Core Web Vitals on Flight Landing Pages (SEO and Metasearch): LCP from 3s to 1.5s, CLS from 0.15 to 0.08, INP from 400ms to 180ms. Page latency from 3s to under 1.5s.
- Maintained mobile web SLO above 99%. Cut server errors from 5M to under 10k and reduced server I/O overhead, driven by production metrics in Datadog.
- Built an AI-assisted delivery workflow with Claude Code: reusable skills that turn a project ticket, PRD, designs and screenshots into structured requirements, so agents work from clean data instead of re-reading raw tickets. One agent implements, another writes test cases for likely bugs and failure modes, then a test, fix and re-test loop runs until everything passes. The workflow produces final documentation and self-test evidence for QA handover.
- Mentored new joiners. Gathered their onboarding struggles and wrote a New Joiner Pocket Book and Checklist. Contact rate to onboarding buddies dropped markedly for the most recent joiners.
- Pixel-perfect UI implementation from design specs, covering spacing, typography and responsive behavior, working directly with designers on edge cases before handoff.
- Tokopedia Salam (Muslim-focused features) for the Content Marketing and IT Enterprise teams. Indonesia has the world's largest Muslim population (200M+), so faith-based features directly drive engagement and retention among a core audience.
- Rebuilt the Al-Quran page for smooth reading. The page was laggy because of the volume of content. Applied list windowing so only the verses and pages the user can see are rendered, and optimized verse and page rendering. Reduced First Input Delay (FID, since replaced by INP in early 2024) from 360ms to 90ms.
- Built an internal tools page builder that replaced repetitive CRUD work (tables, create/edit forms, delete). PMs and non-engineers can now launch new CRUD pages without asking an engineer.
- Managed feature flags and feature controls for homepage widgets, default sort and default filter without redeploys.
- Delivered the Dekara project from scratch under a tight deadline, with complex features.
- Improved developer experience for internal tools and reduced memory consumption when running them locally.
- Raised unit test branch coverage to 85%+.
- Implemented microservices with NestJS using a modular architecture, so modules are reusable and can be split into separate services.
- Delivered 10+ client projects across industries, meeting aggressive deadlines, some completed in as little as 3 days.
- Worked closely with designers and stakeholders across the full lifecycle: planning, implementation, deployment and maintenance.
Technical Skills
Centered on the React, TypeScript, and Next.js ecosystem — backed by config-driven architecture, Core Web Vitals tooling, and AI-assisted engineering workflows.
Frontend, Mobile & Backend
Quality & Performance Tooling
Architecture & Frontend Systems
AI-Assisted Development
Engineering Practices
Languages
Academic foundation
Formal training that underpins the day-to-day engineering practice.
Surabaya, Indonesia
Four years of study in software engineering, data structures, and systems design — the foundation behind the performance-focused engineering work that followed.
Verified on HackerRank
Skills verified through timed, proctored assessments administered by HackerRank.
Demonstrates the ability to build production-grade interfaces with React — covering component architecture, state management, and UI performance.
Demonstrates strong algorithmic thinking and data-structure fluency.
Demonstrates working proficiency in Go for backend and systems-level development.
Demonstrates advanced JavaScript proficiency — closures, asynchronous patterns, and DOM internals.
Demonstrates core React proficiency — components, props, and lifecycle fundamentals.
Demonstrates foundational JavaScript syntax and applied problem-solving ability.
Demonstrates baseline algorithmic problem-solving ability.
Get in Touch
Based in Bogor, Indonesia and open to senior frontend engineering roles — including relocation to Europe, Australia, Singapore, US.