Offline Sync with Conflict Resolution | Dataford Interview Questions

Design a function that merges offline mobile actions into server state. Each action has an item_id, operation type, timestamp, and op_id; duplicate retries must be ignored, the merge order must be deterministic, and conflicting items must be returned separately.

Inputs and Output

local_ops: list of (item_id, op_type, timestamp, op_id)
server_state: current item state before sync
remote_changes: list of (item_id, op_type, timestamp)
Return (final_state, conflicts)

Merge Rules

Ignore repeated op_id values
Apply local actions in timestamp order with deterministic tie-breaking
Flag an item as a conflict if remote changed it after the sync point
Do not apply conflicting local actions

Your question is Offline Sync with Conflict Resolution. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Inputs and Output

local_ops: list of (item_id, op_type, timestamp, op_id)
server_state: current item state before sync
remote_changes: list of (item_id, op_type, timestamp)
Return (final_state, conflicts)

Merge Rules

Ignore repeated op_id values
Apply local actions in timestamp order with deterministic tie-breaking
Flag an item as a conflict if remote changed it after the sync point
Do not apply conflicting local actions

Your question is Offline Sync with Conflict Resolution. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.