Software Engineer

  • Warsaw, Poland
  • On-site
  • Full-time
  • Posted

on Flix's careers page

No Polish required

Salaryzł 90–120 / hour (B2B)

Not mentioned in the job post: visa sponsorship, relocation, where you can apply from

Rate: 90 – 120 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 

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About Flix

Overview

Flix operates the FlixBus and FlixTrain networks and sells bus and train tickets for travel across Europe.