> Markdown version of [/jobs/ext/2729088-backend-fullstack-engineer](https://www.wearedevelopers.com/jobs/ext/2729088-backend-fullstack-engineer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

---

# Backend / Fullstack Engineer

- **Company:** Postaladdress
- **Location:** Berlin, Germany (Remote available)
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** Java (Programming Language), JavaScript (Programming Language), Application Programming Interfaces (APIs), Artificial Intelligence, Databases, Data Integration, Data Structures, Data Synchronization, Database Design, Python (Programming Language), Knowledge Management, PostgreSQL, Microsoft OneNote, Node.Js, Data Streaming, Systems Architecture, Systems Integration, TypeScript, Backend, Build Tools, Pagination, Network Server
- **Published:** September 5, 2026
- **Apply:** https://startup.jobs/senior-backend-fullstack-engineer-decircle-8349843

## About the Role

* 5+ years of experience building production-level backend services.
 * Strong proficiency in JavaScript / TypeScript.
 * Experience with Python, Go, Rust, or Java is a plus.
 * Solid knowledge of SQL databases, with ability to design and query relational and graph-based schemas.
 * Experience working with Notion APIs (Node.js) and orchestrating third-party APIs.
 * Familiarity with pagination, rate limits, and structured data formats.
 * Ability to design and implement efficient algorithms.
 * Experience with Supabase or equivalent modern DB platforms.
 * Strong communication and technical documentation skills.
 * Comfortable working with AI assistants and integrating them into daily workflows.
 * Research mindset - open to exploring and integrating new technologies and protocols.

## Description

You will be working with technologies like Notion, Supabase, Node.js, and various third-party APIs to automate and improve how data is structured, accessed, and maintained across platforms.

You'll also contribute to the development of a custom knowledge management tool that goes beyond the limitations of Notion, enabling complex data queries and improved interoperability with AI assistants and future systems., * Design and implement backend systems for data synchronization between Notion and external databases/workflows.

 * Model hierarchical data structures and implement scalable storage solutions (e.g., Supabase).
 * Build tools to automate the Atlas edit workflow, detecting document structure changes and generating proposals.
 * Develop integrations with third-party APIs and orchestrate data flows across services.
 * Collaborate with cross-functional teams to define system architecture and ensure technical alignment.
 * Research and contribute to building a custom knowledge management platform (e.g., using Model C Protocol Servers).
 * Advocate for and implement AI-assisted tooling within the workflow.


## Related Videos

- [Inside Bitpanda's Tech Stack: Scaling a European Fintech Leader - Markus Dorner](https://www.wearedevelopers.com/videos/1979-inside-bitpanda-s-tech-stack-scaling-a-european-fintech-leader-markus-dorner)
- [Developing the Backend with Stefan Lingler, CTO at Shpock](https://www.wearedevelopers.com/videos/100360-developing-the-backend-with-stefan-lingler-cto-at-shpock)
- [Stop using Node.js like in 2020! What changed and what you can do today with Node.js](https://www.wearedevelopers.com/videos/100011-stop-using-node-js-like-in-2020-what-changed-and-what-you-can-do-today-with-node-js)
- [Kubernetes and Microservices with Multi-Model Databases](https://www.wearedevelopers.com/videos/382-kubernetes-and-microservices-with-multi-model-databases)
- [Meet Your New BFF: Backend to Frontend without the Duct Tape](https://www.wearedevelopers.com/videos/682-meet-your-new-bff-backend-to-frontend-without-the-duct-tape)
- [Nest.js - TypeScript in the backend can also be clean](https://www.wearedevelopers.com/videos/1033-nest-js-typescript-in-the-backend-can-also-be-clean)

## Related Articles

- [Backend Developer Salary in Germany [2023]](https://www.wearedevelopers.com/magazine/196-backend-developer-salary-in-germany-2023)
- [Fullstack developer salary in Germany [2023]](https://www.wearedevelopers.com/magazine/197-fullstack-developer-salary-in-germany-2023)
- [Frontend Developer Salary in Germany [2023]](https://www.wearedevelopers.com/magazine/195-frontend-developer-salary-in-germany-2023)
- [Dev Digest 121 - AI goes offline](https://www.wearedevelopers.com/magazine/456-dev-digest-121-ai-goes-offline)
- [The Most Popular IT Jobs on the Market](https://www.wearedevelopers.com/magazine/376-the-most-popular-it-jobs-on-the-market)
- [Dev Digest 120 - Apple and peers](https://www.wearedevelopers.com/magazine/455-dev-digest-120-apple-and-peers)