Software Engineer (Ruby) – Senior at SOFTSWISS in Warszawa, PL

Overview:

SOFTSWISS is hiring a Senior Software Engineer (Ruby) to join our Data Quality Platform team. We build and own a high-load Data Quality platform used across the company. Our product runs millions of checks every day, helps teams detect and investigate data issues, and provides tools to improve trust in their data.

We are looking for a senior engineer who can independently identify opportunities, shape product direction, build reliable solutions, and take ownership of their production outcomes.

Purpose of the role:

Your primary focus will be core backend platform engineering: architecture, orchestration, data models, PostgreSQL performance and reliability of the DQ runtime.

You will own the production behaviour of the services you build and may contribute to UI features when they are needed to deliver an end-to-end product capability. Frontend and SRE specialisation are not prerequisites: we use AI-assisted workflows and expect strong engineering judgement, ownership and willingness to work across the stack when needed.

Key responsibilities:

• Design and evolve core architecture of a high-load DQ platform running millions of checks per day

• Improve throughput, latency and reliability of orchestration, scheduling, dependency resolution, retries and mutation-driven reruns

• Profile and optimise PostgreSQL-heavy production workloads; the platform's PostgreSQL workload reaches approximately 4,000 RPS

• Lead backend migration of statistics and analytical workloads from PostgreSQL to ClickHouse

• Build and evolve product features around DQ coverage, table lineage, incident lifecycle and operational investigation

• Contribute to platform UI features when they are necessary to deliver an end-to-end product capability, using AI-assisted development workflows

• Own reliability and production behaviour of backend services: investigate incidents, diagnose performance bottlenecks, improve observability and prevent recurrence

• Participate in a 24/7 on-call rotation

• Help scale DQ adoption across the company by making integrations, configuration and operation of checks reliable and approachable

• Work directly with data producers, infrastructure and business teams

• Proactively identify product, technical and operational problems; turn them into well-scoped, production-ready improvements

Required Experience:

• Strong Ruby and Rails skills

• Strong experience developing and operating high-load production systems

• Deep PostgreSQL expertise: query planning and profiling, indexes, locking, transactions, concurrency, connection behaviour and performance tuning under sustained load

• Strong SQL skills and ability to investigate complex data discrepancies across large, multi-source datasets

• Experience with asynchronous systems: background jobs, queues, retries, idempotency and failure recovery

• Experience designing complex backend systems from scratch and evolving them safely in production

• Hands-on production ownership: metrics, logs, tracing, incident investigation and performance analysis

• Strong practical use of AI-powered developer tools: navigating unfamiliar codebases, prototyping, debugging, reviewing and delivering changes faster, while critically validating the result

• Product mindset and entrepreneurial ownership: ability to see an opportunity, formulate a solution, validate it with users or data, and drive it through delivery

• Intermediate or higher English (B1+)
  

Nice to have:

• Familiarity with ClickHouse

• Familiarity with Delta Lake, Trino, Spark or DuckDB

• Experience with Debezium (or any other CDC implementation), Kafka, data ingestion & transformation patterns

• Experience with Kubernetes, Helm, Prometheus/Grafana and production service operations

• Experience building side projects, launching product capabilities, or independently improving a product beyond assigned tasks

Our Benefits:

• Private health insurance

• Sports benefits

• Comprehensive Mental Health Program

• Free English lessons (online)

• Local language courses

• Paid time off

• Maternity leave support

• Referral program rewards

• Upskilling, internal workshops, and participation in professional conferences and corporate events