Lightspeed Senior Software Engineer interview questions

The process started with an initial screening round, followed by a technical interview with system design and then a round with deeper technical discussion with code review. The team was professional and direct throughout the process. Communication from HR was clear and timely. The interviews were heavily focused on core Python fundamentals, concurrency concepts, messaging systems (queues, Kafka/RabbitMQ), transactions, and system design. The technical depth expected was quite high, especially around language-level concepts such as context managers, decorators, and concurrency primitives. In the later round, the discussion became very detailed around Python internals and low-level constructs. When I wasn’t able to confidently explain a specific core concept (context managers), the interview was concluded early with the feedback that for a Senior role, strong fluency in core Python fundamentals is expected. What I liked: Interviewers were technically strong and clearly knowledgeable. Questions were practical and relevant to backend engineering. Clear feedback was given directly. What could be improved: The process felt somewhat unforgiving; the interview was ended early based on one foundational gap rather than evaluating overall system design and backend experience. A slightly more holistic evaluation of seniority (architecture, real-world impact, problem-solving) alongside language fundamentals would make the process more balanced.

The interview process consisted of a recruiter prescreening call, followed by an interview with the engineering manager, and finally an in-depth technical interview focused on problem solving, system design, and practical engineering skills.