Type · Influence

Growth · Software Engineer Interview Guide
Sign up to see ATSHow to Pass the Shopfully Software Engineer Interview in 2026
The Shopfully DNA (TL;DR)
The Shopfully Interview Loop
Your onsite loop will typically consist of 5 rounds.
- 1
Round 1
Recruiter ScreenMotivation, role fit, logistics. - 2
Round 2
Coding ScreenLeetCode-medium algorithmic problems under time pressure. - 3
Round 3
System DesignDistributed systems, trade-offs at scale, architecture under constraints. - 4
Round 4
Onsite CodingLeetCode-hard, debugging, code clarity, edge cases. - 5
Round 5
Behavioral / LeadershipPast evidence of ownership, influence, resolving conflict.
The Danger Zone: Top Reasons Candidates Fail
Based on our database of Shopfully interview outcomes, avoid these common traps:
- Describing a situation where they simply told people what to do.
- Using inappropriate data structures that lead to high memory or slow query times.
- Introducing new bugs while refactoring.
- Insufficiently robust traffic splitting mechanisms leading to biased results.
Test Yourself: Real Shopfully Questions
Three real prompts pulled from our database.
Type · debugging
Type · algorithmic
+ many more questions, signals, and worked examples
Sign up to unlock the JobMentis grading rubric
Shopfully Interview Question Bank
A sample from our database, grouped by round. Sign up to see the full set.
9 of 23 questions shown
Recruiter Screen
1- 1
Type · motivation
What interests you about working at Shopfully, specifically within our advertising and growth teams?
Coding Screen
3- 2
Type · algorithmic
Given a stream of user ad impression events (timestamp, user_id, ad_id, click_flag), design an algorithm to calculate the click-through rate (CTR) for each ad in near real-time. Consider memory constraints and potential for high volume. - 3
Type · algorithmic
Implement a function that takes a list of user segments (defined by a set of properties like 'age', 'location', 'device_type') and a list of ad campaigns (each with targeting criteria). The function should return which campaigns a given user would be eligible for. Assume segments and targeting criteria are represented as dictionaries or JSON objects. - + 1 more questions in this round (sign up to unlock)
System Design
3- 4
Type · system-design
Design a system to detect and prevent ad fraud (e.g., click farms, bot traffic) in real-time for a high-volume ad network. Consider data ingestion, feature extraction, model serving, and actioning. - 5
Type · system-design
Design an A/B testing framework for evaluating new ad creatives or targeting strategies on Shopfully's platform. The system should handle traffic splitting, metric collection, and result analysis. - + 1 more questions in this round (sign up to unlock)
Onsite Coding
3- 6
Type · algorithmic
You are given a large dataset of user interactions with ads (view, click, conversion). Design a data structure and algorithm to efficiently answer queries like: 'What is the conversion rate for ad X among users who clicked on ad Y within the last 24 hours?' - 7
Type · code-clarity
Refactor the following Python code snippet, which calculates the effective cost per mille (eCPM) for ad campaigns, to improve its readability, maintainability, and efficiency. Pay attention to variable naming, error handling, and potential edge cases. - + 1 more questions in this round (sign up to unlock)
Behavioral / Leadership
13- 8
Type · conflict resolution
Tell me about a time you had a significant disagreement with a cross-functional team member (e.g., engineering, marketing) about a product decision. How did you approach the situation, and what was the outcome? - 9
Type · Ownership
Tell me about a time you took ownership of a problem that wasn't directly your responsibility. What was the situation, and what did you do? - + 11 more questions in this round (sign up to unlock)
Unlock the full Shopfully question bank
Free signup, no credit card. You get every question + the framework, grading signals, and worked answer for each.
Interview tracks at Shopfully
How Shopfully's DNA translates across functions. Pick your role.
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Practice Shopfully interviews end-to-end
Shopfully Mock Interview
Run a live mock interview with our AI interviewer using Shopfully-style prompts. Get scored on structure, signal, and answer length — exactly how the real loop grades you.
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STAR Stories for Shopfully Behavioral Rounds
Build a Story Bank of your past wins, mapped to the leadership signals Shopfully interviewers grade on. Reuse them across every behavioral round.
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Shopfully Interview Prep Hub
The frameworks behind every Shopfully round: CIRCLES for product sense, hypothesis-driven debugging for analytical, STAR for behavioral. Learn each one in 10 minutes.
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Interview Frameworks
CIRCLES, STAR, AARRR, RICE, MECE. The exact frameworks that make Shopfully interviewers nod instead of frown. Step-by-step playbooks with the moves and the pitfalls.
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