Type · system-design
How would you design a scalable API service for Acciona's customers to query historical and real-time energy generation data from their installed solar panels? Consider authentication, rate limiting, and data consistency.
How to Pass the Acciona Software Engineer Interview in 2026
Enterprise · Software Engineer Interview Guide
Sign up to see ATSHeadquartered in SpainInterview language: English
The Acciona DNA (TL;DR)
Acciona's 'Sustainability Master Plan' informs interviewers to seek candidates demonstrating a deep understanding of sustainable practices and the ability to integrate them into large-scale infrastructure projects. The final behavioral round often probes for examples of navigating complex regulatory environments and delivering results aligned with their commitment to a 'Circular Economy'.
The Acciona 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 problems, reasoning about defects, 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 Acciona interview outcomes, avoid these common traps:
- Focusing solely on personal career growth without demonstrating an understanding of Acciona's business or values.
- Insufficient planning for API endpoint design and versioning.
- Choosing a monolithic architecture instead of a distributed, scalable one suitable for IoT data.
- Using algorithms that are too computationally expensive for real-time processing.
Test Yourself: Real Acciona Questions
Three real prompts pulled from our database.
Type · debugging
A system that aggregates energy production data from various renewable sources (solar, wind, hydro) is reporting inconsistent totals. Here's a simplified snippet of the aggregation logic. Identify the potential bug and suggest a fix.
Type · algorithmic
Given a list of solar farm energy production readings (timestamp, megawatt-hours) over a year, write a function to find the contiguous period with the highest average energy production. Consider edge cases like no production days or all days having zero production.
+ many more questions, signals, and worked examples
Sign up to unlock the full Acciona grading rubric
Acciona Interview Question Bank
A sample from our database, grouped by round. Sign up to see the full set.
9 of 12 questions shown
1
Recruiter Screen
1- 1
Type · motivation
Acciona is a global leader in renewable energy and sustainable infrastructure. What specifically about our mission and work in the energy sector excites you and aligns with your career aspirations as a Software Engineer?
2
Coding Screen
3- 2
Type · algorithmic
Given a list of solar farm energy production readings (timestamp, megawatt-hours) over a year, write a function to find the contiguous period with the highest average energy production. Consider edge cases like no production days or all days having zero production. - 3
Type · algorithmic
Imagine you have sensor data from wind turbines, reporting their current power output and wind speed. Design a data structure and write a function to efficiently query the maximum power output for a given wind speed range. Assume queries will be frequent. - + 1 more questions in this round (sign up to unlock)
3
System Design
3- 4
Type · system-design
Design a system to monitor and predict potential failures in a large network of distributed solar inverters. The system should ingest real-time telemetry data, identify anomalies, and alert maintenance teams proactively. - 5
Type · system-design
Design a system to optimize the charging and discharging of a large battery storage facility connected to the grid, aiming to maximize revenue by arbitraging electricity prices while ensuring battery health. - + 1 more questions in this round (sign up to unlock)
4
Onsite Coding
2- 6
Type · algorithmic
Implement a function that takes a list of wind farm locations (latitude, longitude) and a list of weather forecast data points (timestamp, location, wind speed) and efficiently determines which wind farms are likely to experience optimal wind speeds (e.g., within a specific range) within the next 24 hours. Optimize for large datasets. - 7
Type · algorithmic
You are given a stream of real-time energy demand data points for a city. Design and implement a system to detect sudden, significant spikes or drops in demand that might indicate an anomaly or a grid event. The system should operate with low latency.
5
Behavioral / Leadership
3- 8
Type · past-experience
Tell me about a time you had to work with a legacy system or codebase at Acciona that was difficult to understand or modify. What steps did you take to gain understanding, make your changes, and what was the outcome? - 9
Type · past-experience
Describe a situation where you identified a significant technical debt or performance bottleneck in a system critical to Acciona's operations (e.g., grid management, energy trading). How did you prioritize addressing it, and what was the result? - + 1 more questions in this round (sign up to unlock)
Unlock all 12 Acciona 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 Acciona
How Acciona's DNA translates across functions. Pick your role.
Compare Acciona with similar employers
Same DNA, different bar. Browse the closest companies in our database and see how their loops differ.
EDF
Same tierEDF's 'Une Data' initiative anchors their evaluation, grading how candidates model complex energy grids and align wit...
See EDF interview questions
Siemens Energy
Same tierEngineering and operational safety at Siemens Gamesa drives the evaluation criteria. Interviewers look for candidates...
See Siemens Energy interview questions
Severn Trent
Same tierSevern Trent's core values of 'Care, Share, Pride, Trust' anchor their loop, where interviewers look for safety-first...
See Severn Trent interview questions
Practice Acciona interviews end-to-end
Acciona Mock Interview
Run a live mock interview with our AI interviewer using Acciona-style prompts. Get scored on structure, signal, and answer length - exactly how the real loop grades you.
Open
STAR Stories for Acciona Behavioral Rounds
Build a Story Bank of your past wins, mapped to the leadership signals Acciona interviewers grade on. Reuse them across every behavioral round.
Open
Acciona Interview Prep Hub
The frameworks behind every Acciona round: CIRCLES for product sense, hypothesis-driven debugging for analytical, STAR for behavioral. Learn each one in 10 minutes.
Open
Interview Frameworks
CIRCLES, STAR, AARRR, RICE, MECE. The exact frameworks that make Acciona interviewers nod instead of frown. Step-by-step playbooks with the moves and the pitfalls.
Open
Sample answers
What a strong answer to these Acciona interview questions shows.
How would you design a scalable API service for Acciona's customers to query historical and real-time energy generation data from their installed solar panels? Consider authentication, rate limiting, and data consistency.
A strong answer shows: Designs a well-structured and scalable API; Addresses security and performance concerns; Considers data access patterns and database choices; Demonstrates understanding of distributed system components.
A system that aggregates energy production data from various renewable sources (solar, wind, hydro) is reporting inconsistent totals. Here's a simplified snippet of the aggregation logic. Identify the potential bug and suggest a fix.
A strong answer shows: Identifies concurrency issues; Proposes a correct and efficient fix; Explains the reasoning behind the fix.
Frequently asked questions
How long does the Acciona interview process take?
Most candidates spend between 4 and 8 weeks from recruiter screen to offer. The onsite loop itself runs in a single day or is split across two half-days, with debrief and offer typically within 5 business days after.
How should I prepare specifically for Acciona?
Focus on three things: (1) the company DNA shown above - what they actually grade for, (2) the rounds in your loop, especially the round most candidates underestimate, and (3) drilling on the question types in this guide using a structured framework like CIRCLES or STAR.
Does this apply to engineering or design roles at Acciona?
The DNA stays the same - what changes is the round mix. SWE candidates face coding screens instead of Product Sense; designers face portfolio reviews and design exercises. The "what they value" and behavioral signals carry across all functions.
Explore careers on Workfive →