I applied online. The process took 6 weeks. I interviewed at Sierra Studio
Interview
The hiring process is a redundant waste of time. Completing an architecture take-home task only to repeat the exact same topic in a System Design interview shows a complete lack of internal coordination and zero respect for a candidate's effort.
The technical interview was a total disaster. The interviewer arrived late, was visibly distracted, and lacked the basic skills to lead the session. What was supposed to be a pair programming exercise turned into a solo task because he couldn't provide any clear requirements. When I questioned the lack of direction, he claimed it was normal and told me I was doing well. I was rejected anyway.
This was a clear case of gaslighting. The interviewer was either utterly incompetent or simply too lazy to care. He couldn't even answer basic questions about the company's own hiring stages. If this is the level of leadership and preparation they offer to senior candidates, it is a massive red flag. Do not waste your time here.
I applied online. I interviewed at Sierra Studio (Rio de Janeiro) in Nov 2025
Interview
almost 7 steps including live coding and system design interview. Live coding was about building ai agents without a framework only using open ai sdk. Interview with Head of AI was different than usual for me. They ask about leadership and technical questions about AI enginnering.
Interview questions [1]
Question 1
Create a tool calling ai agent capable of cordinating a calendar app
O processo seletivo foi totalmente online e bastante estruturado. Primeiro houve uma entrevista com o RH, focada em alinhamento cultural e avaliação do nível de inglês. Em seguida, participei de uma entrevista técnica com o Tech Lead e o CTO da Sierra, onde foram discutidas decisões de arquitetura, experiências anteriores e abordagem para resolução de problemas. Após essa etapa, caso passe será um teste técnico com live coding, conversando com um desenvolvedor da equipe. Por fim, uma entrevista final com o CEO.
Interview questions [2]
Question 1
Uma das perguntas feitas foi sobre a decisão entre desenvolver um framework próprio de agentes ou utilizar uma solução já existente no mercado, como o LangChain, explicando critérios técnicos, trade-offs e contexto de negócio.
