Software Engineer w Warszawa, Polska

Rate: 89 – 119 PLN/hour (B2B) 

We are looking for an experienced Software Engineer to join Flix on a freelance/service agreement basis (B2B contract) . This is a contractor engagement for a seasoned engineer who wants to work on impactful, hands-on engineering challenges. 

Scope of Services 

Build and scale the customer service platform that handles millions of passenger conversations across markets — from AI-powered chatbots and voice agents to help center and knowledge base tools. We run a polyglot stack (Python, TypeScript, Terraform) on AWS, integrating Twilio, Cognigy, Kafka and AWS Bedrock. We ship continuously and own our services end-to-end, from Terraform to production. 

About the Engagement

• Design, build and maintain Python (FastAPI) backend services and TypeScript/React frontends across the CS platform
• Take greenfield products from concept to production — make architectural calls, prototype, validate, and iterate under uncertainty
• Develop and extend Twilio Functions (JavaScript) for voice/IVR and webchat flows
• Manage the infrastructure as code with Terraform (HCL) on AWS — you build it & deploy it
• Integrate third-party and AI platforms: AWS Bedrock, Twilio, Cognigy, LiteLLM, Kafka
• Apply AI to your engineering practice — use and help improve our internal AI tooling to ship faster and raise quality
• Instrument and monitor services (Datadog, event forwarding, alerting) and respond to production issues 

About You

• 2–4 years building production software
• Strong in Python (FastAPI or similar) and comfortable in TypeScript/JavaScript (React a plus)
• Hands-on with AWS and infrastructure-as-code (Terraform)
• Solid Git workflow, CI/CD, and containerized services (Docker)
• Strong ability to navigate vague or shifting requirements — a bias for action, comfort making decisions with incomplete information, and the judgment to avoid analysis-paralysis
• Pragmatic, ships iteratively, communicates clearly
• Curious about and comfortable working with AI tooling in day-to-day development 

Preferred Skills:  

• Experience building products from scratch (0→1) in a fast-moving team
• Conversational AI / chatbot / IVR experience (Twilio, Cognigy, DialogFlow)
• LLM / GenAI integration (Bedrock, RAG, MCP servers)
• Event streaming (Kafka) and observability (Datadog)
• Customer-service or contact-center domain exposure 

Collaboration Model

• Cooperation based on a service agreement (B2B/freelance contract), not an employment contract
• You will operate as an independent contractor, responsible for delivering agreed services and submitting invoices
• Location: open for contractors based in Poland