Senior Backend Developer

Senior

Remote

Full-time

B2B:
19 000 - 23 000 PLN net + VAT

UoP:
We are looking for a senior engineer to grow the backend and the workflow engine behind Workflow Builder, and to take the product into customer environments. You own modules end to end, from design through deployment to production support.

What you will bring to the table

About this job opening

We build Workflow Builder, our product for designing and running processes visually. It gives automation platforms a workflow editor on the front end and a durable execution engine underneath.

You will grow that backend and workflow engine, deploy the product at customers, and connect it to their systems.

This is a hands-on senior role with a short path from decision to production.

What might surprise us

What you will do

Develop the product backend, the API, and the mechanics that execute workflow graphs.

Build and grow integrations with external systems.

Run customer deployments and connect the product to customer systems.

Scale workers and improve the performance and reliability of running processes.

Design modules, write tests, diagnose production issues, and review code.

Your work in detail

What we expect

Must have:
Strong TypeScript and Node.js, with production experience building backends.

Production experience with Temporal or another durable execution engine, and readiness to work with Temporal.

A clear grasp of determinism and replay, retries, durable timers, and resumptions. You can safely change code that handles processes already in flight.

Idempotency, deduplication, partial failure handling, and compensation. You understand dependencies between steps and parallel workflow branches.

Designing and shipping systems that scale. Horizontal scaling of workers in Temporal or a similar engine, concurrency control, and removing bottlenecks.

PostgreSQL at high data volumes: query tuning, indexes, partitioning, transactions, and migrations.

Hands-on work with Redis or similar systems, including cache, TTL, invalidation, and data consistency.

Deploying and running applications on Azure or AWS. You know one of them and are ready to work in the other.

REST APIs, webhooks, and SSE (server-sent events). Authentication, permissions, customer data isolation, and secrets management.

Docker, CI/CD, integration and load tests, monitoring, and failure diagnosis.

Experience working with AI agents on implementation, tests, or code analysis. You review their changes and want to keep working this way.

English at C1 level.

Nice to have:
React and React Flow.

Temporal TypeScript SDK.

Kubernetes, Terraform, and OpenTelemetry.

How we operate

How you work with us

You run tasks on your own, from design through deployment to maintenance.

You agree on requirements with the customer and the team. You flag risks and blockers, and bring solutions with them.

You share knowledge, take part in code reviews, and act on feedback.

You discuss technical solutions with customers in English.

Work model: remote or hybrid. Our office is in Wroclaw if you like working on site.

Technology

Ongoing

Ongoing

Senior Backend Developer

Senior

Remote

Full-time

B2B:
19 000 - 23 000 PLN net + VAT

UoP:
Got any questions? Contact Magda, your recruitment guardian.

[email protected]

Your next great workspace goes beyond just a job

Partnerships with leading tech

Certified UI/UX, PMs, DevOps & more

Collaborations with Just Join IT

Prestigious office building

Living culture and social life

Curious about interview?

The conversation lasts about 2 hours. It is a bit long, but we don’t have more interviews, follow-ups, or homework assignments. We try to ensure a friendly, informal atmosphere to reduce stress. You don’t need to worry.

Got any questions?

[email protected]

Ready to join the #Squad?

At Synergy Codes, you’ll work on cutting-edge solutions, collaborate with top experts, and grow in a culture that values your creativity and innovation.