[Documentation] Feature flag Service

[vikhyat187]

My understanding of feature flag service.

• Users can be enabled or disabled from https://dashboard.realdevsquad.com/ Ans : yes
• I feel it's more of a platform service, used across all the services in RDS.
  Ans : Not only RDS it can also be given to external people to integrate it.
• We can use this to release a feature, to allow a subset of people to access the feature. (beta users) Ans : for 1% of users, to a specific user or to a group of users.
• The backend is build in node js Ans : We need to check some language which is highly quick (very scalable and responsive)
• The current database is Mongodb. Ans : We can check on the database to be on Mongodb or move to Dynamodb.

Open questions

• what are the features that are yet to be developed?

• Already developed paths

  • GET Feature Flags
  • create feature flag
  • edit feature flag
  • delete feature flag
  • find feature flag

• Is the UI developed completely? Ans : Not yet

• Is this deployed somewhere? Ans : No

• Are we having plans to move to AWS -> yes

  • what all AWS services are we planning to use? Ans : Lambda(serverless) based on pricing.

• Since its platform service, I feel we have not created an SDK, should I explore how it can be done? Ans : Yes, we can check on creating an SDK for react native, SDK for native android, SDK for web, SDK for ios. (create epics
  for them)

• What all sites are we trying to integrate to? Ans : All sites.

https://github.com/Real-Dev-Squad/todo-action-items/issues/59 https://www.atlassian.com/continuous-delivery/principles/feature-flags

[vikhyat187]

MOM: Sync with Gaurav 7th March 2023

1. How user management is handled, explore that. Ans : we have user model , we can use that.
2. If MongoDB, how are we planning to host it self-managed or cloud-managed? Ans : Look at the price diff and decide on that.
3. How much scalability do we want the service to serve? Ans : For now around 2k to 2.5k users.
4. What should be the runtime? Docker or lambda? Ans : We can start with Lambda and move to docker based on the usage.
5. Choose the language based on the runtime. E.g Java takes time for cold start in lambda Ans : To avoid coldstart we can use Cloudfare workers, it doesn't have coldstart like Lambdas.
6. How much scalable is railway.app (the current deployment platform for website-backend)
7. What is the pricing for railway.app Ans : Currently we use the free tier Memory per container. 512 MB CPU per container 2 vCPU Shared disk 1 GB
8. The database can be SQL or NoSQL (need to think more on this) Ans : Mostly it will be NoSql.
9. Look out for how the existing feature flag service works launch darkly
10. The plan of release should be like Version - 1: Have the feature flag enabled on the user level (for a user) Version - 2: Have the feature flag enabled on the group of users Version - 3: Have it for a percentage of users
11. How the user journey would be Ans. How feature flag can be created -> from dashboard site by super_user The feature flag would be accessed by consumer to check if the user is authorised to use the feature.

[vikhyat187]

MOM: Sync 11th March 2023

1. Check on the user API, do we have an API that returns the users belonging to a group (This is for version-2)
2. The data access pattern will be like a. get me all the users belonging to the group b. get the feature flag for a user c. to get X per cent of random users, which do not have the feature flag enabled.
3. Create API designs by @vikhyat187 a. To create a feature flag b. To read a feature flag c. To update a feature flag d. To delete a feature flag
4. We can use Dynamodb for database
5. Gaurav will compare the costing between Docker with least memory and lambda
6. Do we have logging for the services to debug?