I’m David Stotijn,
an Amsterdam-based software engineer.

Senior Software Engineer with 10+ years of experience building full-stack web applications on AWS and GCP.

I love working with startups and scale-ups on interesting product and engineering challenges. My specialty is full-stack web development, with senior level experience using Go, TypeScript (Node.js), React and Svelte. I deliver pragmatic and high quality solutions on a deadline.

Curious how I can add value to your team as a Freelance Software Engineer?

Highlighted Experience

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

• 

  Freelance Software Engineer

  2022—present

  For MRA-Elektrisch, performed backend (Go) and frontend (AngularJS) development, adding features that empower Dutch municipalities to better plan, build and manage +10k public EV charging stations. Keywords: APIs/RPCs, process/workflow management, PostgreSQL, PostGIS.

  For Crate, built and maintained Python backend services and (RAG) pipelines on AWS Lambda to support their AI-powered content saving and curation platform. Implemented product features for AI-assisted content categorization, curation and reporting. Helped further develop their mobile app using React Native.

  For GitBook, integrated error tracking and logging for Cloudflare Workers with their existing observability stack, improving stability of the platform. Extended the customer-facing REST API (TypeScript, Firebase) with new endpoints for user management, improved single sign-on (SAML, OIDC) workflows, and built a proof of concept for a Terraform provider (Go).

• 

  Framer

  2019—2021

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

  I built a pipeline on AWS for automated screenshotting of Framer project canvases. Queue workers (SQS), browser automation (Playwright), image processing (Sharp), file storage (S3).

• 

  MessageBird

  2015—2019

  I designed and built the (Go) backend of Flow Builder: a no-code product used +1M/month by B2C customers for automating chat, email and voice workflows. Keywords: Go, Cloud Spanner, Docker, Kubernetes, RESTful APIs.

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/hetty6,969 stars

• go-notion

  Go client for the Notion API.

  

  dstotijn/go-notion383 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.