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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Data Engineer (Node/TS) - **Company:** MentionLab - **Location:** Brussel, Belgium - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** Application Programming Interfaces (APIs), Artificial Intelligence, Code Review, Databases, Data Architecture, Data Deduplication, Cursor (Graphical User Interface Elements), Python (Programming Language), PostgreSQL, Node.Js, Operational Databases, Performance Tuning, Query Optimization, Queue Management Systems, Redis, Software Engineering, SQL Databases, TypeScript, Sql Optimization, Large Language Models, Data Layers, Kubernetes, Data Management, Vertica, NestJS, Docker - **Published:** September 22, 2026 - **Apply:** https://www.adzuna.be/details/5890317245 ## About the Role Technical Requirements: * 5+ years of engineering experience, including building and running production data pipelines * Strong, hands-on experience with data modelling, query optimisation and performance tuning on an analytical database (ClickHouse strongly preferred) * Solid Node.js/TypeScript skills: our pipelines are written in TypeScript, not Python * Advanced SQL * Experience with queue-based or event-driven processing at scale (retries, idempotency, backpressure) * Comfortable working across both analytical and transactional databases * Experience with AI-assisted development tools (Copilot, Cursor, Claude Code, or similar), * Rust experience, or strong interest in picking it up * Experience with NestJS, PostgreSQL, Redis/BullMQ * Processing unstructured or multilingual text data (e.g. LLM outputs) * Delivering data to external consumers (APIs, exports, data feeds) * Infrastructure knowledge (Docker / Kubernetes, observability) * Previous startup experience You'll Thrive Here If You enjoy figuring things out and don't need hand-holding. You're comfortable with ambiguity and changing priorities. You like collaborating and sharing what you learn. You're excited about AI and its impact on how people discover information. And you're AI-native: you don't just build AI products, you build with AI. ## Description As a Senior Data Engineer at MentionLab, you'll own the data layer at the heart of our product. You'll design and run the pipelines that turn raw AI answers into reliable, structured data. You'll also build the ClickHouse models that power our analytics platform and partner deliveries. Our pipelines are built in Node.js and TypeScript, so this role suits a data engineer with strong software engineering skills. If you love analytical databases at scale, care deeply about data quality, and want to own meaningful parts of a product from day one, this role is for you. What You'll Build * Own our data architecture end to end: ingestion, transformation, storage and delivery * Build and scale the pipelines that process what AI engines say across markets, languages and models * Design ClickHouse data models and queries that stay fast as volumes grow * Guarantee data quality through validation, deduplication, monitoring and backfills * Run high-throughput, queue-based processing reliably in production * Work mainly in TypeScript and SQL, with Rust for performance-critical processing * Raise the engineering bar through code reviews, standards and mentoring The Stack * TypeScript (Node.js) and SQL, with some Rust; * NestJS with MikroORM and Knex on PostgreSQL; * ClickHouse for analytical workloads; * Redis for queue management (BullMQ + custom tooling for high throughput)., Languages: French required. English working proficiency for documentation and some meetings. Location: Belgium-based (Brussels - hybrid). Permanent contract (CDI) - 38h/week. What We Offer Fair salary package including car/mobility budget and insurance Small, ambitious team A chance to shape the technical direction of the company High level of autonomy with guidance when needed: you're not alone! ## Related Videos - [Coffee with Developers - Maria Apazoglou](https://www.wearedevelopers.com/videos/1209-coffee-with-developers-maria-apazoglou) - [Nest.js - TypeScript in the backend can also be clean](https://www.wearedevelopers.com/videos/1033-nest-js-typescript-in-the-backend-can-also-be-clean) - [Docker Compose: Rediscovered](https://www.wearedevelopers.com/videos/1978-docker-compose-rediscovered) - [Reducing LLM Calls with Vector Search Patterns - Raphael De Lio (Redis)](https://www.wearedevelopers.com/videos/1714-reducing-llm-calls-with-vector-search-patterns-raphael-de-lio-redis) - [Streaming AI Responses in Real-Time with SSE in Next.js & NestJS](https://www.wearedevelopers.com/videos/1630-streaming-ai-responses-in-real-time-with-sse-in-next-js-nestjs) - [Docker build without Docker](https://www.wearedevelopers.com/videos/100114-docker-build-without-docker) ## Related Articles - [Dev Digest 121 - AI goes offline](https://www.wearedevelopers.com/magazine/456-dev-digest-121-ai-goes-offline) - [Dev Digest 120 - Apple and peers](https://www.wearedevelopers.com/magazine/455-dev-digest-120-apple-and-peers) - [Dev Digest 159: AI Pipelines, 10x Faster TypeScript, How to Interview](https://www.wearedevelopers.com/magazine/563-dev-digest-159-ai-pipelines-10x-faster-typescript-how-to-interview) - [Navigating the AI Shift](https://www.wearedevelopers.com/magazine/629-navigating-the-ai-shift) - [How to Become an AI Engineer](https://www.wearedevelopers.com/magazine/331-how-to-become-an-ai-engineer) - [7 Most Popular Web Developer Jobs in Europe](https://www.wearedevelopers.com/magazine/163-7-most-popular-web-developer-jobs-in-europe)