Senior Backend Engineer

beqom; Kraków; On-site; PLN 240,000 - 360,000; Full time

Job summary

beqom in Kraków is seeking a Senior Backend Engineer to join the Data Platform Core team, owning services at the heart of our data architecture, including multi-tenant data ingestion, schema management, and analytics-ready contracts.

You will collaborate with Data Platform, Analytics, Support, and Product teams in an AI-first environment, leveraging .NET 8/C#, PostgreSQL, and MassTransit to deliver scalable, observable backend services.

Qualifications

• 5+ years of production backend development
• Strong SQL and PostgreSQL design and optimisation
• Experience with multi-tenant SaaS architectures

Responsibilities

• Design and build features across multi-tenant data platform services
• Collaborate with Data Platform, Analytics, Support and Product teams
• Mentor engineers and contribute to agent-driven development practices

Skills

Senior backend engineer

.NET/C#

SQL/PostgreSQL

AI-driven development

Multi-tenant SaaS

Excellent written communication

Tools

EF Core

Dapper

MassTransit

RabbitMQ

Claude Code

OpenTelemetry

Job description

Join beqom - where tech meets impact

beqom is a high-growth B2B SaaS company that provides industry-leading tools for pay equity and transparency, compensation, and performance management.

Trusted by some of the world’s most respected companies, beqom enables HR and business leaders to navigate global compliance and make smarter pay decisions that attract, retain, and motivate top talent.

Founded in Switzerland and serving clients worldwide, our powerful, enterprise-ready products are fuelled by beqom pay intelligence.

Role Overview

We are looking for a Senior Backend Engineer to join our Data Platform Core team, which owns the services at the heart of beqom’s data architecture - multi-tenant data ingestion, schema management, snapshots, calculated fields, and the data contracts powering analytics and reporting across the product.

You will collaborate closely with Data Platform and Analytics engineers, Support teams, and Product stakeholders. We are an AI-first engineering team - Claude Code, agent orchestration, and automated review workflows are how we build by default, and we expect you to help push that practice further.

What you'll be doing

• Feature Development
  • Design and build features across multi-tenant data platform services: data ingestion, schema management, effective dating, snapshots, calculated fields, and exports.
  • Work hands-on with .NET 8/C#, PostgreSQL, EF Core, Dapper, MediatR (CQRS), and RabbitMQ (MassTransit) event-driven workflows.
  • Optimise performance-critical paths: bulk ingestion, large data exports, memory-efficient streaming, and complex SQL.
• Agentic Development
  • Deliver most of your output through AI agents: decompose features into well-structured specifications, run parallel agent sessions, and review outcomes critically before they ship.
  • Build and maintain the team’s agentic tooling: custom Claude Code skills and sub-agents, MCP tools exposing internal APIs, prompt/context conventions (CLAUDE.md), and automated review pipelines.
  • Design the verification that makes agent speed safe: test strategy, quality gates, and evals that catch hallucinated APIs, subtle logic errors, and performance regressions in generated code.
• Quality & Collaboration
  • Investigate and resolve production data issues in collaboration with Support and Engineering.
  • Maintain strong test coverage: unit and integration tests.
  • Improve observability (OpenTelemetry) and operational stability.
  • Document architecture decisions and write clear, actionable PRs and commit messages.
  • Mentor other engineers - in backend craft and in effective agent-driven development - and raise the bar in code reviews.

Skills & Experience

What you'll bring

• Demonstrated senior-level experience building production backend services with .NET/C#.
• Strong SQL and PostgreSQL skills: schema design and query optimisation.
• Proven performance and memory awareness - streaming vs. buffering, profiling and load-testing skills - and the ability to judge whether AI-generated solutions meet performance and scalability needs.
• Track record of shipping features that are complete and stable, backed by strong test discipline.
• Experience with multi-tenant SaaS architectures.
• Deep, daily experience with AI-driven development - Claude Code strongly preferred - including multi-agent orchestration, building custom skills and sub-agents, and structuring codebases and context for effective agent work.
• Experience turning requirements into precise, agent-executable specifications, and reviewing AI output at the feature level: spotting hallucinations, architectural drift, and security issues.
• Excellent written communication: design docs, specifications, PR descriptions, and commit history that both humans and agents can act on.

Bonus points if you have

• Experience building MCP servers or exposing internal APIs as agent-callable tools.
• Experience with LLM evaluation: eval suites, behavioural test design, or benchmarking agent workflows.
• Functional programming in C# (LanguageExt - Either/Option patterns).
• CDC/event-driven ingestion (Debezium, Kafka) or lakehouse exposure (Microsoft Fabric).
• Azure services, Docker, Kubernetes/Helm.
• Familiarity with compensation, HR, or pay transparency domains.

Why join us?

• Your career, your design. Unleash your ambition in our dynamic, autonomous environment.
• Drive meaningful change. Build a fairer future for every employee by joining a market leader that is improving the world of work.
• Belong to something bigger. Collaborate with a passionate, diverse and talented team around the globe.