Experienced Django REST API Framework developer for a full-time

We are an international team and our goal is to build a Platform in a micro-service architecture. Some of these micro-services: Django Rest API (PostgreSQL), Jupyter Notebook Server, BlockChain Contracts API, graph DB etc. Each side has it's own developers' sub-team.

Django API is responsible for handling requests from web-UI clients, managing graph DB entries, triggering Celery tasks to initiate execution process in Jupyter Notebook Server, requesting BlockChain Contracts API.

Requirements
We are looking for middle-level (as minimum) Django developer with perfect experience of working with:

1. Rest API Framework
2. Docker.
3. Celery.
4. Git.
5. GraphQL.

An ability to construct complex query selectors is required.

The developer should be able to work with the complex logic cases and wishes to catch new experience with high-end developments.

Responsibilities
For the first period it is supposed that the right person will update present models and methods in case of UI usages.

For the next period the developer will work on:

1. Architecting new schemas for a present business need.
2. Extending present BlockChain requests (via GraphQL).

Terms
We are looking for a full-time developer. The test period is a month. After that the right person can be hired for a long term.

The question
Describe your experience by required list.

As test question
Let’s say you have a model `some_object` without field `type`, but data is already in DB.
How can you insert `type` ForeignKey to SomeObjectType model into `some_object` to get as the result the field `type`:

1. Is not nullable.
2. Has not default value.