Shahriar M Abu Hena, Senior Fullstack Engineer at Mollie
fullstack engineer · payments, platforms & developer experience
Fullstack engineer with 12+ years of building product end to end: the services and data models underneath, the interfaces people actually touch on top, and the platform work that holds the two together. Fintech, SaaS, e-commerce and healthcare.
Right now I build payments at Mollie, Europe’s fastest-growing PSP, across the Acceptance & Risk and Core Payment Experience domains: checkout SDK architecture, express payments and wallets, real-time infrastructure, and fraud tooling that analysts actually trust.
A normal week runs the whole stack. Node and PHP services, Postgres schemas, queues and event flows, React, Svelte and TypeScript on the surface, then the Docker, GitLab CI and GCP plumbing that ships it. I like owning a feature from the database column to the pixel, because that is where the interesting bugs live.
I care most about system design and developer experience: the unglamorous work that lets a hundred teams ship without stepping on each other. Migrations with zero downtime, CI that stays green, design systems people reach for by default.
Lately: LLM-assisted test automation, MCP servers, and agent harnesses that do real work instead of demos.
Experience
Senior Software Engineer, Mollie B.V.
Feb 2022 to present · Amsterdam, Netherlands
- Built the fraud BI product end to end: ML-driven detection wired to configurable risk-appetite controls, a dynamic 3-D Secure decisioning layer, and the analyst-facing tooling on top.
- Core developer on the Mollie Checkout SDK: architecture in TypeScript, React and Svelte, integrated by merchants at scale.
- Directed the real-time infrastructure migration from WebSockets (Pusher) to Server-Sent Events. Fewer session drops, +20% conversion.
- Shipped an embedding-based MCP indexing service for AI coding assistants, cutting context-retrieval time during onboarding.
- Led express checkout and digital wallet integrations, plus the hosted-checkout migration.
- Pioneered LLM-assisted E2E automation with Playwright + BrowserStack across critical payment paths.
- Cut monolith build times and modernised the GitLab CI / Docker / GCP pipeline.
- Mentored medior and intern engineers on design systems, testing and architecture.
Senior Frontend Engineer, Rabobank N.V.
Jun 2020 to Jan 2022 · Utrecht, Netherlands
- Core platform team supporting 100+ squads and 300+ developers in a single Nx monorepo.
- Led the monorepo-wide Angular / NgRx / Nx migration with zero disruption to business continuity.
- Wrote a custom AST-based migration strategy so 100+ squads could upgrade gradually and non-blockingly.
- Modernised CI/CD and the E2E stack (WebdriverIO, Cypress, Jest). Materially less flake, tighter feedback loops.
- Acted as technical lead: architectural direction, monorepo tooling, mentoring.
Engineering Consultant, iO (formerly Frontmen)
Jul 2019 to Jan 2022 · Amsterdam, Netherlands
- Engineering consultancy for enterprise clients including Rabobank and VodafoneZiggo.
- Contributed to in-house product work and the engineering culture.
- Helped organise the 2019 FrontMania conference.
Software Engineer, Spotcap Global GmbH
May 2018 to Jun 2019 · Berlin, Germany
- Built the Aurum 2 lending platform with a functional-programming approach in TypeScript, React and Redux.
- Owned the Document Recognition workflow end to end, a critical piece of the loan application pipeline.
- Shaped and extended the internal design system across applications.
Lead Fullstack Engineer, Aaroza InfoTech
Jun 2016 to May 2018 · Dhaka, Bangladesh
- Early engineer on GrowthFunnel: established the platform foundation and the team.
- Led core JavaScript SDK development and built admin / user management in a microservice architecture.
- Introduced Redis caching and Node.js multithreading to clear concurrency bottlenecks.
- Integrated AWS ALB with Route53 for region-based routing.
Fullstack Engineer, AirVuz Inc
May 2015 to May 2016 · Dhaka, Bangladesh
- Built a video encoding pipeline and editor UI on the MEAN stack + AWS.
- Implemented Media Source Extensions with MPEG-DASH and an HLS fallback for adaptive streaming.
- Replaced Wowza with a custom MSE-based solution: lower infra cost, better performance.
Freelance Fullstack Developer, Upwork
Sep 2011 to 2017 · Remote
- 60+ projects delivered with a 100% success rate as a Top-Rated freelancer.
- ~15 hybrid mobile apps with native-feel UX, plus direct client comms and delivery.
Projects
CuocoMitra
Recipe discovery, nutrition tracking and live cooking guidance. Nx monorepo with LLM tool-calling agents, a Next.js SSR site, and native iOS/Android apps.
cuocomitra.comApp StoreGoogle Playsrt-webvtt
Tiny npm package that converts SRT subtitles to WebVTT on the fly in an HTML5 environment. Quietly powers a lot of video players.
GitHubnpmvideo-thumb-generator
Generates thumbnails/screenshots from a video in the browser, producing Blob or base64 output. No server round-trip.
GitHubbrowsentic
Reimagines browsing as agentic, driven by the AI agent you already run, inside your own logged-in browser session.
GitHubrender-visual-skill
Lets Claude Code, Cursor, Copilot and Codex render real images and animations instead of describing them.
GitHubcredit-card-scanner
OpenCV + webcam credit-card OCR with web-worker concurrency, running entirely client-side.
GitHubled-strip-web-bluetooth
Connect to and drive Bluetooth LED strips straight from the browser using the Web Bluetooth API.
GitHub
Skills
- Languages: JavaScript, TypeScript, PHP
- Backend: Node.js, REST & GraphQL, Microservices, Event-driven systems
- Frontend: React, Next.js, Design systems, Svelte, Angular, Micro frontends (Module Federation)
- Data: PostgreSQL, MongoDB, Redis
- Testing: Jest / Vitest / Mocha, Testing Library, Cypress, Playwright, WebdriverIO
- Platform: Docker, CI/CD, Nx monorepo, GCP / AWS, GitLab CI, GitHub Actions, Datadog
- AI: LLMs & RAG, MCP servers, Agent harnesses & evals