Type · algorithmic
Given a list of customer IDs and their corresponding energy consumption data for a month, find the top N customers with the highest consumption, optimizing for performance.
Growth · Software Engineer Interview Guide
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How to Pass the Octopus Energy Software Engineer Interview in 2026
The Octopus Energy DNA (TL;DR)
Octopus Energy seeks individuals passionate about green energy, customer advocacy, and collaborative problem-solving. They assess alignment with their "tentacles" (values) like honesty, simplicity, and a drive to make a positive impact, alongside practical skills and adaptability.
The Octopus Energy 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 Octopus Energy interview outcomes, avoid these common traps:
- Providing a vague description of the problem without detailing the troubleshooting process.
- Not considering caching strategies for frequently accessed data.
- Failing to articulate the trade-offs clearly (e.g., performance vs. maintainability, speed vs. correctness).
- Failing to correctly model the interaction between solar generation, grid import/export, and battery state.
Test Yourself: Real Octopus Energy Questions
Three real prompts pulled from our database.
Type · motivation
What interests you about working in the energy sector, and specifically at Octopus Energy?
Type · system-design
Design an API service that allows customers to view their historical energy consumption data, filter by date range, and download reports. Discuss potential bottlenecks and how to mitigate them.
+ many more questions, signals, and worked examples
Sign up to unlock the full Octopus Energy grading rubric
Octopus Energy Interview Question Bank
A sample from our database, grouped by round. Sign up to see the full set.
9 of 13 questions shown
1
Recruiter Screen
1- 1
Type · motivation
What interests you about working in the energy sector, and specifically at Octopus Energy?
2
Coding Screen
3- 2
Type · algorithmic
Given a stream of smart meter readings (timestamp, energy_consumed), write a function to calculate the peak consumption hour for a given day, handling potential out-of-order or missing readings. - 3
Type · algorithmic
Implement a function to determine if a customer's energy usage pattern (represented as a list of hourly consumption values) matches a predefined tariff profile, allowing for a certain tolerance percentage. - + 1 more questions in this round (sign up to unlock)
3
System Design
3- 4
Type · system-design
Design a system to ingest, process, and store real-time smart meter data from millions of households for billing and analytics purposes. Consider data volume, velocity, and variety. - 5
Type · system-design
Design an API service that allows customers to view their historical energy consumption data, filter by date range, and download reports. Discuss potential bottlenecks and how to mitigate them. - + 1 more questions in this round (sign up to unlock)
4
Onsite Coding
3- 6
Type · algorithmic
Write a function to simulate the charging and discharging of a home battery system based on solar generation, grid prices, and user-defined preferences (e.g., prioritize self-consumption, minimize cost). - 7
Type · debugging
A customer reports that their monthly bill seems incorrect, showing much higher consumption than usual. Here's a snippet of the processed meter data and the billing calculation logic. Find the bug. - + 1 more questions in this round (sign up to unlock)
5
Behavioral / Leadership
3- 8
Type · behavioral
Tell me about a time you had to work with a difficult stakeholder or team member. How did you approach the situation and what was the outcome? - 9
Type · behavioral
Describe a time you faced a significant technical challenge or a bug that was difficult to track down. What steps did you take to resolve it, and what did you learn? - + 1 more questions in this round (sign up to unlock)
Unlock all 13 Octopus Energy questions, free
No credit card. Every question with its framework, the grading signals interviewers score against, and a worked answer for each.
Interview tracks at Octopus Energy
How Octopus Energy's DNA translates across functions. Pick your role.
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Practice Octopus Energy interviews end-to-end
Octopus Energy Mock Interview
Run a live mock interview with our AI interviewer using Octopus Energy-style prompts. Get scored on structure, signal, and answer length - exactly how the real loop grades you.
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STAR Stories for Octopus Energy Behavioral Rounds
Build a Story Bank of your past wins, mapped to the leadership signals Octopus Energy interviewers grade on. Reuse them across every behavioral round.
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Octopus Energy Interview Prep Hub
The frameworks behind every Octopus Energy 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 Octopus Energy interviewers nod instead of frown. Step-by-step playbooks with the moves and the pitfalls.
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Sample answers
What a strong answer to these Octopus Energy interview questions shows.
Given a list of customer IDs and their corresponding energy consumption data for a month, find the top N customers with the highest consumption, optimizing for performance.
A strong answer shows: Knowledge of efficient data structures (heaps).; Optimization for finding top K elements.; Scalability considerations..
What interests you about working in the energy sector, and specifically at Octopus Energy?
A strong answer shows: Genuine interest in sustainability and energy transition.; Understanding of Octopus's business model and market position..
Frequently asked questions
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