Nubank Senior Software Engineer Interview Experience — Chargeback Ingestion and a Database Read Bottleneck

Nubank·Software Engineer·Sep 2026
OnsiteSenior+Rejectedmedium

Problem: Design a Chargeback Ingestion System

Design a system that processes card chargeback/dispute transactions.

The system receives chargeback-related transaction events, validates and deduplicates them, tracks their processing state, persists them, and eventually exports eligible transactions into CSV files. These CSV files must be sent to Mastercard via FTP/SFTP.

The difficulty felt all right. I failed mainly because there was a database-read bottleneck that I didn't recognize at the time. Batched reading would actually have solved it. The interview experience was all right.

Published

Curated and edited by PracHub

Practice the questions from this interview

Discussion

Sign in to join the discussion. The author is notified of every comment.

Loading comments…

Interview at a glance

Company
Nubank
Role
Software Engineer
Level
Senior+
Rounds
Onsite
Outcome
Rejected
Difficulty
medium
Interview date
Sep 2026
Questions from this interview
1 question

Real Nubank interview experiences

First-hand reports from Nubank candidates — the rounds, the questions they were asked, and how it went.

All 6 Nubank interview experiences