Senior Backend Developer (freelance)

About the role

We are looking for a senior backend engineer who will own the technical direction of IoT projects from architecture to production. The role is freelance, time‑and‑material, fully remote, with the possibility to join the core team permanently after a successful trial.

Key responsibilities

• Design, build and evolve backend architecture for connected‑device platforms, including data ingestion pipelines and APIs.
• Make and defend technical trade‑offs to both internal teams and clients.
• Implement and maintain production‑grade cloud infrastructure on AWS (EKS, Aurora, DynamoDB, Timestream, S3).
• Lead technical discussions such as RFCs, architecture reviews and post‑mortems.
• Mentor other backend engineers and set coding standards.
• Collaborate daily with firmware, mobile, QA, product and client stakeholders.
• Integrate AI tools into the development workflow to increase productivity.

Required profile

• Strong experience building backend systems for IoT or similar data‑intensive products.
• Comfort with ambiguity and ability to create structure without detailed specifications.
• Excellent communication skills for explaining trade‑offs to technical and non‑technical audiences.
• Self‑starter who can work fully remote and deliver high‑quality code.

Required skills

• AWS services: EKS, Aurora, DynamoDB, Timestream, S3.
• Design and implementation of data ingestion pipelines.
• API design and development.
• Cloud infrastructure provisioning and reliability engineering.
• Experience with IoT backend architectures.

What we offer

• Freelance contract with competitive hourly rates.
• Full‑time capacity from day one and a clear path to a permanent role.
• Remote‑first culture with optional coworking spaces in Warsaw and Gdansk.
• Access to cutting‑edge AI tools used daily in product development.