Backend Engineer (Node.js)

Quick Facts

• Role: Freelance Backend Engineer (Node.js)

• Focus: IoT backend architecture, data pipelines, cloud infrastructure, and technical leadership

• Work model: Fully remote; flexible hours with some evening calls for US clients

Description

Join as a freelance Backend Engineer to own and evolve backend architecture for IoT projects end-to-end, including data ingestion pipelines, API design, and infrastructure decisions. Lead technical trade-offs with clear explanations to both the team and clients, and drive architecture practices through RFCs, reviews, and post-mortems. Collaborate closely with firmware, mobile, QA, PM, and clients, using AI tools as part of your daily workflow.

Responsibilities

• Own and evolve backend architecture for IoT projects (data ingestion pipelines, API design, infrastructure decisions)

• Make and defend technical trade-off decisions

• Design and maintain AWS cloud infrastructure with production-grade reliability

• Lead technical discussions: RFCs, architecture reviews, post-mortems

• Mentor backend engineers and raise code quality standards

• Collaborate with firmware, mobile, QA, PM, and clients

• Use AI tools daily in practical development workflows

• Challenge product and technical assumptions when they don’t add up

Requirements

• 7+ years of backend development with a meaningful portion spent leading technical direction

• Strong production Node.js skills at scale

• Hands-on AWS expertise: EKS, Aurora, DynamoDB, Timestream, S3

• Experience with Kubernetes (EKS), Docker, and Terraform

• Solid understanding of distributed systems, event-driven architectures, and data pipelines

• Experience with MQTT or similar IoT messaging protocols

• CI/CD pipelines you have designed yourself (GitHub Actions, GitLab CI, Jenkins)

• English B2+ (written and spoken)

• Ability to translate business needs into technical decisions and communicate them to non-technical stakeholders

• Ability to hold strong opinions while staying open to changing direction based on evidence

Benefits

• 90–180 PLN/h net B2B (depending on experience) during freelance period; time-and-materials model

• Flexible working hours; fully remote

• Option for Warsaw office / Gdansk coworking

• Internal knowledge sharing (tech talks, experiments, side projects)

• After 3 months (if a good match): path to permanent contract with fixed monthly salary, 26 days paid leave, 10 sick days, Saltus medical care, and a training budget

• Note: during the freelance period there are no paid leave or medical benefits; those come with the permanent contract