Requirements

Functional Requirements:

• Log workouts
• View history & basic stats.
• Sync across devices.

Non-Functional Requirements:

• user can log and view history offline
• supported in devices and app
• high availability

API Design

1.) GET : v1/workout?type={type}

2.) GET : v1/workout/user/{id}?date_range={}&stats={}

3.) POST : v1/workout/user/{id}

req body: { workout, workout_type, time, count, calories, stats }

High-Level Design

flowchart TD

 B["client"];

 C{"server"};

 D["Database"];

 E(("CND"));

 F{"Load Balancer"};

 rd[("redis cache")];

 ag["API gateway"];

 B --> E;

 E --> F;

 F --> ag;

 ag --> C;

 C --> rd;

 C --> D;

at the api level in server we will provide rate limiting for post or get on user

caching for get, and when post clear cache on that user

we use post to sync all the data when user comes online

i can use a hash structure on the workout info for deduplication

Detailed Component Design

• First is how we sync from offline, we store a structure data in or mem cache of device, and when offline this will synced to data base with hashing for deduplication.
• rate limiting
• caching we use redis on a user level and workout
• for common data like workouts data if we get from a 3rd party we cache that, so the api now does'nt hit the 3rd party everytime
• we use postgress db, with jsonb functionality
• implementing large/slow uploads, using async obviously and batching large data for uploads during mostly when offline sync.