Google New Grad CodeSignal Fragments: Bank Transfers and In-Memory Database

Role: Software Engineer, New Grad
Result: Waitlisted
Report time: September 2025

The post contains two screenshots from a CodeSignal-style assessment. Both are partial fragments rather than complete tasks.

Fragment 1: Simple Bank transfer

A transfer(timestamp, sourceAccountId, targetAccountId, amount) operation should:

• Withdraw and hold funds from the source account
• Keep funds held until the target accepts or the transfer expires
• Return held funds to the source when the transfer expires
• Return null for a same-account transfer
• Return null when either account does not exist
• Return null when the source lacks sufficient funds
• Expire after 86,400,000 milliseconds, at the beginning of the next millisecond

The screenshot omits the remaining transfer and acceptance behavior plus earlier task levels.

Fragment 2: in-memory database

The visible operations are:

• set(timestamp, key, field, value): create or replace a field
• compareAndSet(...): replace only when the current value equals the expected value
• compareAndDelete(...): remove only when the current value equals the expected value
• get(...): return the field value or null when missing

The screenshot omits the overall wrapper, examples, constraints, and later levels.

Because both captures are incomplete, filling the missing levels from memory would risk inventing the assessment. No exact practice link is asserted. A commenter asked how screenshots were possible if camera monitoring was required, but no answer was preserved.