I’m David Stotijn, a software engineer from Amsterdam.

Hello, and welcome! This is my little home on the web where I talk about work and write bits and bobs on software development.

About me

Ever since I can remember I’ve had a keen interest in tinkering with computers and building things with them. I’ve been lucky enough to make a living doing just that for well over a decade. Aside from crafting software, I really enjoy playing piano and guitar. I live in Amsterdam with my girlfriend and son.

Work

I’m a Freelance Software Engineer with 10+ years’ experience building and maintaining web applications and services on cloud infrastructure.

I love working with teams on interesting product and engineering challenges, approaching them with a pragmatic mindset. My area of expertise is backend web development using Go and TypeScript (Node.js), but I also know my way around React and Svelte on the frontend.

Below is a list of selected work experience. For full details, read my CV (PDF).

• 

  Hetty Software (Self-employed)

  2022 — present

  For Eventpartners, I designed and built an MVP of a multi-tenant SaaS platform for event planning & management. Keywords: Node.js (NestJS), React, PostgreSQL, Prisma, Apollo GraphQL, codegen, Jest, Google Cloud Run.

  For Invopop (YC W23) I built GOBL Builder, a low-code editor for reviewing and creating electronic invoice documents. Keywords: Go, WebAssembly, Svelte, Monaco Editor, Web Workers. Additionally, I helped refactor a legacy admin dashboard to SvelteKit, using Tailwind UI and Firestore.

• 

  Framer

  2019 — 2021

  Developed web services (Go, Node.js, TypeScript) and infra on AWS for automated certificate management (using Let’s Encrypt) and site hosting (EC2, DynamoDB, S3, CloudFront).

  Built a pipeline for automated screenshotting of Framer project canvases for Dashboard and Open Graph. Queue workers, browser automation, image processing, storage (SQS, Playwright, Sharp, S3).

• 

  MessageBird

  2015 — 2019

  As a Tech Lead, I designed and built the (Go) backend of Flow Builder, a no-code service used +1M/month by B2C customers for automating chat, email and voice workflows.

  Built developer-friendly RESTful APIs and backend services (Go, PHP) for SMS, Chat and Voice products.

Side projects

• Hetty

  An HTTP toolkit for security research. It aims to become an open source alternative to Burp Suite Pro, with powerful features tailored to the needs of infosec and bug bounty professionals.

  dstotijn/hetty 5,166 stars

  

• go-notion

  Go client for the Notion API.

  dstotijn/go-notion 328 stars

  

Articles

• Apr 27, 2021
  Portable apps with Go and Next.js

  How-to guide for embedding a web interface in your Go app.
• Nov 11, 2018
  Bypassing SSL certificate pinning on Android for MITM attacks

  Step-by-step guide for bypassing SSL certificate pinning on Android for MITM attacks.