Senior Backend Engineer - AI / Node / Express / TypeScript (5+ Years)

Dopelist; Barcelona; Presencial; EUR 50.000 - 70.000; Jornada completa

Descripción de la vacante

A tech-driven organization in Barcelona is seeking a Senior Backend Engineer to architect data flow systems across platforms. The ideal candidate will have 5-8 years of experience in backend development with strong skills in Node.js and Typescript. Responsibilities include managing data synchronization and AI integration for dynamic features. This role promotes continuous delivery and collaboration with the CTO. Candidates can expect a fast-paced environment with opportunities for ownership and improvement.

Formación

• 5-8 years of backend development experience.
• Strong expertise in Node and Typescript, with a focus on clean code practices.
• Experience with cloud infrastructure and platform integrations.

Responsabilidades

• Architect systems for data flow across multiple datastores.
• Manage real-time data synchronization and integration.
• Design scalable cloud architecture on AWS or GCP.

Conocimientos

Node.js

Typescript

Backend Development

Cloud Architecture

AI Integration

Herramientas

Firebase Functions

PostgreSQL

GitHub Actions

OpenAI API

Descripción del empleo

Senior Backend Engineer at Dopelist (Barcelona)

AI / Node / Express / PostgreSQL / Typescript (5+ years)

About Dopelist

Dopelist is a collection and discovery app that helps users organize their digital chaos—from places and bookmarks to voice notes and people. We are building a platform that marries curation with AI‑powered discovery.

Opportunity

You will architect the systems that power data flow across our entire platform. This is a heavy integration role involving semantic search, social feeds, and synchronization between multiple datastores.

Key Responsibilities

• Real‑time Systems & Data Proliferation Managing the flow and synchronization of data across multiple datastores (Firebase Firestore, PostgreSQL, qdrant vector DB, Algolia search indexes, GetStream feeds). You’ll build systems that keep data consistent and performant across platforms, handling real‑time updates, webhooks, and event‑driven architectures.
• AI / ML Integration Building AI‑powered features like semantic search, content categorization, and intelligent recommendations. You’ll work with OpenAI APIs, embeddings, vector databases (qdrant), and agent frameworks to bring intelligence to the platform. We use promptfoo for evaluation and testing.
• Cloud Architecture & Infrastructure Designing scalable systems on AWS / GCP, optimizing Firebase Functions, managing deployments on Render.com, implementing monitoring and observability, and ensuring system reliability across our distributed architecture.

What we’re looking for

• 5‑8 years of backend development experience.
• Strong Node / Typescript expertise: You write clean, type‑safe backend code and understand async patterns, error handling, API design principles, and ideally DDD.
• Platform integration / multiple datasource experience: You’ve integrated third‑party services / SAAS products and the data connections between them. We’re using queues on GCP and Firebase write triggers to handle multiple destinations (e.g., Algolia, Qdrant, BigQuery, GetStream).
• Cloud Platform knowledge: Bit by bit we’re architecting our cloud infra. This will become more important as we trial different third parties and ultimately own our own entire infrastructure.

Nice to have

• Experience with Firebase ecosystem (Functions, Firestore, Auth, Storage)
• Vector database and semantic search experience (qdrant, Pinecone, etc.)
• AI / ML integration background (OpenAI, embeddings, agent frameworks)
• Real‑time systems experience (WebSockets, pub/sub, event streaming)
• Experience with search platforms (Algolia, Elasticsearch)
• Social platform integrations (GetStream, feeds, activity streams)
• WhatsApp Cloud API or messaging platform experience

The Tech Stack

• Backend: Node.js, Express, TypeScript, Firebase Functions
• Databases: PostgreSQL (Prisma), Firebase Firestore, qdrant (vector DB)
• Integrations: Algolia (search), GetStream (social feeds), OpenAI (AI / ML)
• Cloud: AWS / GCP, Render.com, Firebase hosting
• Tools: GitHub Actions, promptfoo (AI evals), Jest, Postman
• AI: Agents SDK, Embeddings

Success Profile

We value shipping, ownership & continuous improvement. We’re moving extremely quickly and to do that we adhere to continuous delivery principles—we ship backend updates constantly, sometimes multiple times a day.

This means we keep each other unblocked on code reviews, test each other’s work & take responsibility for systems shipped as a team. You’ll work closely with the CTO on database architecture decisions and data modeling. We impose WIP limits & value pairing over working in parallel.

You’ll own the health and performance of backend systems while collaborating across the stack.

Hiring Process

• First chat / screening
• Technical interview (Systems Design)
• Technical interview (Technical Challenge)
• Final interview / offer stage