Senior Backend Engineer, Customer Data Platform

Jobtailor; Warszawa; On-site; PLN 180,000 - 320,000; Full time

Job summary

Jobtailor is seeking a skilled engineer in Warsaw to own critical data and delivery pipelines. The role emphasizes Node.js/TypeScript development, deep Elasticsearch expertise, and Kafka-scale operations.

You will manage production ownership, cross-team integrations, and robust incident response. Candidates should demonstrate strong English, Kubernetes/GitOps skills, and experience with high-volume, multi-tenant data platforms.

Qualifications

• Daily, fluent Claude Code practice on production code.
• Strong Node.js and TypeScript skills, including ESM, strict tsconfig, and Jest/Mocha.
• Deep Elasticsearch 8.x knowledge, including mappings, reindexing, sort and range semantics, deep pagination.
• Kafka-at-scale experience, including partitioning, consumer concurrency and lag, dead-letter handling, and topic lifecycle.
• Production ownership experience with on-call, evidence-backed root cause analysis, Datadog instrumentation, toggle-gated rollouts, and profiling-driven performance work.
• PostgreSQL experience with an ORM, including migrations, indexing, and transaction semantics.
• Willingness to own Kubernetes, Helm, GitOps, and GitLab CI.
• Experience with dependency and CVE triage.
• Clear technical English.
• Ability to hold a technical position with product and business stakeholders.
• Nice-to-have: MCP servers, agent skills, V8 isolates, ClickHouse, Aerospike, ArangoDB, Redis, gRPC, Testcontainers, WireMock, Rush, pnpm workspaces, high-volume multi-tenant data platforms, and maintenance-level Java

Responsibilities

• Deliver through Claude Code and improve context, agent tooling, and evaluation of agent output
• Own event-pipeline services under load spikes and pathological traffic, including backpressure, load shedding, circuit breakers, retries, and dead lettering
• Own the Elasticsearch query and search layer, including deep pagination and behavior under memory and rate limits
• Own sandboxed execution of customer logic and integrations with Piano products and third-party systems
• Drive integration work across team boundaries and coordinate cross-service rollouts
• Scope epics and technical trade-offs with technical, product, and business counterparts
• Create decision records for other teams to build against
• Review teammates' work with depth scaled to risk and test determinism
• Run production changes end to end through Helm and FluxCD GitOps
• Participate in on-duty rotation covering alerts, P1/P2 triage, hotfixes, and root-cause communication to enterprise customers

Skills

Node.js Development

TypeScript Proficiency

Elasticsearch 8.x Expertise

Kafka-at-Scale Experience

Production Ownership

Tools

Helm

GitLab CI

FluxCD

Jest

Mocha

Job description

• Deliver through Claude Code and improve context, agent tooling, and evaluation of agent output
• Own event-pipeline services under load spikes and pathological traffic, including backpressure, load shedding, circuit breakers, retries, and dead lettering
• Own the Elasticsearch query and search layer, including deep pagination and behavior under memory and rate limits
• Own sandboxed execution of customer logic and integrations with Piano products and third-party systems
• Drive integration work across team boundaries and coordinate cross-service rollouts
• Scope epics and technical trade-offs with technical, product, and business counterparts
• Create decision records for other teams to build against
• Review teammates' work with depth scaled to risk and test determinism
• Run production changes end to end through Helm and FluxCD GitOps
• Participate in on-duty rotation covering alerts, P1/P2 triage, hotfixes, and root-cause communication to enterprise customers

Requirements

• Daily, fluent Claude Code practice on production code
• Strong Node.js and TypeScript, including ESM, strict tsconfig, and Jest/Mocha
• Deep Elasticsearch 8.x knowledge, including mappings, reindexing, sort and range semantics, deep pagination, and backpressure
• Kafka-at-scale experience, including partitioning, consumer concurrency and lag, dead-letter handling, and topic lifecycle
• Production ownership experience with on-call, evidence-backed root cause analysis, Datadog instrumentation, toggle-gated rollouts, and profiling-driven performance work
• PostgreSQL experience with an ORM, including migrations, indexing, and transaction semantics
• Willingness to own Kubernetes, Helm, GitOps, and GitLab CI
• Experience with dependency and CVE triage
• Clear technical English
• Ability to hold a technical position with product and business stakeholders
• Nice-to-have: MCP servers, agent skills, V8 isolates, ClickHouse, Aerospike, ArangoDB, Redis, gRPC, Testcontainers, WireMock, Rush, pnpm workspaces, high-volume multi-tenant data platforms, and maintenance-level Java

Core Competencies

Demonstrates expertise in Node.js and TypeScript development, with a strong focus on Elasticsearch and Kafka for high-performance data handling. Proven ability to manage production environments, coordinate cross-team integrations, and communicate effectively with technical and business stakeholders.

Highest-signal resume keywords

• Node.js Development
• TypeScript Proficiency
• Elasticsearch 8.x Expertise
• Kafka-at-Scale Experience
• Production Ownership

ATS Optimization Keywords

Hard Skills

• Claude Code Practice
• PostgreSQL with ORM
• Kubernetes Management
• GitOps with Helm
• Datadog Instrumentation
• Dependency and CVE Triage
• Backpressure Management
• Transaction Semantics
• Reindexing
• Consumer Concurrency

Soft Skills

• Clear Technical English
• Cross-Team Collaboration
• Stakeholder Communication

Industry Keywords

• Event-Pipeline Services
• Load Shedding
• Dead Lettering
• High-Volume Multi-Tenant Data Platforms
• Toggle-Gated Rollouts

Tools & Technologies

• Helm
• GitLab CI
• FluxCD
• Jest
• Mocha