Mid/Senior Software Engineer

Company

Checkstep

Date Posted

12-06-2025

Location

Porto, Porto, Portugal / Lisbon, Lisbon, Portugal

Remote

Location: Remote (You must live in Portugal - please do not apply if not based in Portugal)

Team Size: Small, cross-functional teams of 4–5 members

Experience Level: Minimum 5 years of professional experience



About Checkstep

Checkstep builds tools that help online platforms and communities moderate harmful content. Our technology blends AI, automation, and human insight to help customers build safer, healthier spaces for users online.


We’re a small, fast-moving team working on challenging problems in content moderation, trust & safety, and machine learning — and we’re growing.  We practise agile techniques allowing us to deploy multiple times per day with a very low defect rate.



The Role

We’re looking for a mid/senior software engineer to join our backend team. You’ll be working mostly on the backend, but potentially touching full-stack and infrastructure work as needed. We're a small team, so versatility and the ability to learn fast are more important than mastery of any specific tool or framework.



What You’ll Work On

  • Building and maintaining backend APIs and services using Python and FastAPI
  • Stream processing pipelines with Kafka and our custom async processing library (built on top of aiokafka)
  • Working with PostgreSQL and OpenSearch
  • Infrastructure work using Terraform and AWS
  • Occasionally frontend on our SPA React applications
  • We do have 24x7 support and you will participate in on-call rotation that could include some nights and weekends. 



What We’re Looking For

  • 5+ years of experience as a software engineer
  • Comfortable designing, building, and maintaining production systems
  • Strong fundamentals in at least one backend language or framework — doesn’t have to be Python/FastAPI (Go, Java, Django, etc. are all fine). We believe good engineers can learn new tools.
  • Clear communication skills and a collaborative approach to problem-solving (all communications are in English)
  • Based in Portugal



Nice to Have

  • Experience with stream processing or asynchronous systems
  • Familiarity with Terraform and AWS services
  • Knowledge of Elasticsearch/OpenSearch
  • Comfortable being on-call or working in high-availability environments



Why Join Checkstep?

  • Mission-driven work — we’re building real solutions to help make the internet safer
  • Small, collaborative team with real impact and autonomy
  • Remote-first culture with flexibility (within Portugal)
  • Opportunities to work on complex problems in real-time systems, infrastructure, and trust & safety