I love working on open source projects as well as open sourcing my own projects. Beyond my day job I'm currently working on Feuerstein, essentially a setup where I'm building the data pipelines (foerderturm repo) and infrastructure (bergschacht CDK repo) for trading research which is essentially fully open source.

I also spent quite a bit of time recently looking into codegen, OpenAPI and Smithy, while writing SDKs for some financial APIs I realized that a lot of the logic like pagination and rate limiting (see my Redis based ratelimiter here) can be shared so I created an API client SDK framework - spitzeisen. To eventually be able to generate code from just an OpenAPI spec or a Smithy model I'm hoping to use smithy-translate but for now we need to finalize OpenAPI 3.1 support.

Note: None of the projects are "AI slop", please don't open PRs that came from your AI agent and didn't go through human review. If you have an LLM generate something and then reviewed it yourself, submission are welcome.

My SDKs:

• massive-api - Massive.com API, I've added a few API endpoints I needed but more to follow
• eodhd-py - Async Python client for EODHD financial data APIs
• spitzeisen - Python framework for API clients with shared retries, pagination, rate limiting and response validation
• steindamm - Rate limiters with local and Redis backends (used by every SDK)

Feuerstein - financial data pipelines/processing:

• foerderturm - Market data ingestion with Dagster
• bergschacht - AWS infrastructure, pipelines and data-lake schemas
• bergtalzug - Python ETL pipelines with queues and workers
• seilbahn - GitHub Actions workflows
• bergschacht-custom-resources - CDK custom resources e.g. for managing S3 Tables

Languages I enjoy the most:

• Python🐍 for automation and data processing/collection with DuckDB and polars
• Rust🦀 for anything where performance matters - e.g. all the trading strategies I have are written in Rust (sadly can't be open sourced)
• TypeScript(CDK) for infrastructure
• Scala - a new language I got to use just recently but find very elegant
• Java - I don't really interact with it outside of work but when I do it's very welcome