Preparing for the Moloco interview loop requires a balanced strategy that prioritizes rapid problem-solving, deep architectural knowledge, and clear communication. You must be ready to demonstrate both theoretical depth and practical execution.

Algorithmic Speed and Accuracy – Moloco's technical screening relies heavily on highly timed coding assessments. You must be able to quickly identify optimal data structures, write syntactically correct code, and dry-run your solution against complex edge cases without relying on trial-and-error.

Scalability and Low-Latency Thinking – When discussing system architecture, always frame your decisions around scale, latency, and resource constraints. Interviewers evaluate your ability to make sensible trade-offs between consistency, availability, and latency in a high-throughput environment.

Handling Technical Ambiguity – You must show that you can take a vaguely defined problem, ask clarifying questions to establish functional and non-functional requirements, and systematically break down the solution into concrete engineering tasks.

Collaborative Communication – Throughout the live coding and system design sessions, explain your thought process clearly. Your interviewers want to understand how you arrive at a solution, how you respond to constructive feedback, and how you collaborate under pressure.

The interview process for a Software Engineer at Moloco is rigorous, highly technical, and designed to evaluate your capabilities across multiple dimensions. The loop typically begins with an initial recruiter screen to discuss your background, career goals, and compensation expectations. Following a successful screen, you will proceed to a highly time-constrained online coding assessment.

If you pass the online assessment, you will move into the core technical rounds. This stage consists of a technical phone screen (focused on live coding), followed by the virtual onsite loop. The onsite loop typically features 2 to 3 live coding interviews, a system design interview (for mid-to-senior roles), and a behavioral or hiring manager discussion. The engineering team values precise, working code and structured architectural planning, meaning every round is heavily focused on practical execution.

The timeline above details the typical progression from your initial application to the final offer decision. Candidates should use this visual roadmap to pace their preparation, ensuring they allocate sufficient time to practice speed-coding before the online assessment and system architecture design before the onsite loop. While the exact number of rounds can vary slightly depending on your target seniority level and location, the emphasis on technical execution remains consistent globally.

High-Speed Algorithmic Execution

This area evaluates your core programming proficiency, knowledge of data structures, and ability to optimize code under strict time constraints. Moloco's engineering culture values clean, performant, and bug-free code.

Be ready to go over:

• Core Data Structures – Deep familiarity with hash tables, linked lists, trees, graphs, and heaps.
• Algorithm Optimization – Transitioning solutions from naive time complexities to optimal runtimes (e.g., $O(N^2)$ to $O(N \log N)$ or $O(N)$).
• String and Substring Manipulation – Efficient parsing and pattern matching techniques.
• Advanced concepts (less common) – Bit manipulation, dynamic programming optimization, and custom concurrency models.

Example questions or scenarios:

• "Optimize a sliding window algorithm to find the maximum sum of contiguous ad clicks within a specific time window."
• "Implement an in-memory cache eviction policy (such as LRU or LFU) with $O(1)$ lookup and insertion times."

Low-Latency Distributed System Design

For senior and staff-level roles, this is the most critical evaluation area. You must demonstrate that you can design resilient, distributed systems capable of processing massive volumes of data with minimal latency.

Be ready to go over:

• High-Throughput Ingestion – Designing pipelines using message queues (e.g., Kafka) and stream processing frameworks.
• Caching Strategies – Utilizing multi-tier caching (e.g., Redis, Memcached) to reduce database load and latency.
• Database Selection – Choosing the right storage engine (SQL vs. NoSQL, columnar vs. key-value) based on read/write patterns.
• Advanced concepts (less common) – Consistent hashing algorithms, CAP theorem trade-offs in global deployments, and network protocol optimizations (gRPC vs. HTTP/2).

Example questions or scenarios:

• "Design a real-time bidding proxy that interfaces with external ad exchanges, ensuring responses are returned within a strict 100ms SLA."
• "Architect an analytics logging pipeline that can ingest 10 billion events per day and support real-time querying for advertisers."

Behavioral and Leadership Evaluation

This section assesses your communication style, project management capabilities, and how you handle professional challenges. Moloco seeks engineers who are proactive, adaptable, and capable of working across functional boundaries.

Be ready to go over:

• The STAR Method – Structuring your answers by describing the Situation, Task, Action, and Result.
• Handling Ambiguity – Demonstrating how you successfully delivered a project when requirements were constantly shifting.
• Technical Leadership – Showcasing how you mentored junior engineers or influenced architectural decisions on your team.
• Advanced concepts (less common) – Managing cross-functional dependencies, resolving deep technical disagreements, and handling project failures.

Example questions or scenarios:

• "Tell me about a time you disagreed with a product manager's roadmap. How did you present your technical concerns, and what was the resolution?"
• "Describe a project you led that failed to meet its initial timeline. What went wrong, and what did you learn from the experience?"