Senior Software Engineer - JavaScript developer

Circana; Courbevoie; À distance; EUR 70 000 - 110 000; Plein temps

Résumé du poste

Circana is seeking a senior JavaScript Developer with strong web scraping experience to design and build data collection applications at scale. You will work with NestJS, Puppeteer, and a microservices architecture to process terabytes daily and deliver actionable insights for Circana customers.

You will collaborate across engineering teams to ensure robust scrapers, optimize memory and performance, and maintain data quality.

Qualifications

• Strong JavaScript experience with Node.js and NestJS.
• Production web scrapers in JavaScript, headless browser automation.
• DB knowledge with PostgreSQL and query optimization.
• REST API development and microservices architecture.
• Proficient in Agile Scrum practices and cloud familiarity.

Responsabilités

• Design, code, test and deliver scrapers for large scale data collection.
• Maintain robust scrapers and optimize performance and reliability.
• Collaborate with stakeholders to define interfaces and integration points.
• Ensure data quality and resilience against site changes and anti-scraping defenses.
• Mentor teammates and contribute to architectural decisions.

Connaissances

JavaScript

NestJS

Web scraping

REST APIs

Agile Scrum

Cloud experience

Design patterns

HTML parsing

Puppeteer

CI/CD

Formation

Bachelor's degree in Computer Science or related field

Outils

PostgreSQL

Cheerio

Puppeteer

XPath/CSS selectors

Description du poste

Let’s be unstoppable together! At Circana, we are fueled by our passion for continuous learning and growth, we seek and share feedback freely, and we celebrate victories both big and small in an environment that is flexible and accommodating to our work and personal lives. We have a global commitment to diversity, equity, and inclusion as we believe in the undeniable strength that diversity brings to our business, employees, clients, and communities. With us, you can always bring your full self to work. Join our inclusive, committed team to be a challenger, own outcomes, and stay curious together. Circana is proud to be Certified™ by Great Place To Work®. This prestigious award is based entirely on what current employees say about their experience working at Circana.

JavaScript Developer – Web Scraping

Let’s be unstoppable together! At Circana, we are fueled by our passion for continuous learning and growth, we seek and share feedback freely, and we celebrate victories both big and small in an environment that is flexible and accommodating to our work and personal lives. We have a global commitment to diversity, equity, and inclusion as we believe in the undeniable strength that diversity brings to our business, employees, clients, and communities. With us, you can always bring your full self to work. Join our inclusive, committed team to be a challenger, own outcomes, and stay curious together. Circana is proud to be Certified™ by Great Place To Work®. This prestigious award is based entirely on what current employees say about their experience working at Circana. Learn more at www.circana.com.

What will you be doing?

We are looking for a JavaScript developer with strong, hands‑on experience in web scraping, who will design the solution and be involved in the end‑to‑end development and maintenance of our data collection applications. The role is to build large scale, data‑centric applications for advanced analysis, using JavaScript with NestJS, ORM (object relational mapping), solid database knowledge and a microservices architecture. A significant part of the work involves designing and maintaining scrapers that collect data reliably from external sources at scale. A typical application would process terabytes of data on a daily basis to determine Key Performance Indicator for the customers and deliver mission‑critical insights. Given the massive data volumes and time‑sensitive goals of the analysis, applications need to use the latest techniques in data streaming, memory management, parallel execution, distributed messaging and code optimization. Applications must be robust, fault‑tolerant, and highly accurate as they deliver key business insights to senior management for Circana customers. You will be working along‑side other engineers and developers working on different layers of the infrastructure. Therefore, commitment to collaborative problem solving, sophisticated design, and creating quality products is essential. An outstanding candidate will write scrapers and services that are resilient when target sites change, accurate at high volume, and straightforward for others to maintain.

Job Responsibilities

• Independently design, code, unit test and deliver testable user stories.
• Demonstrate solutions through documentation, diagrams, code comments with optimized code.
• Engage with key stakeholders, internal and external to develop interfacing specifications and plan integration checkpoints
• Ability to analyze the issue in detail and provide multiple solutions approach to a problem statement - Develop high quality applications that meets the performance and scalability standards in a cloud platform.
• Work in a fast‑paced environment and deliver releases independently for the end users.
• Work closely with other team members in guiding software architecture and technology decisions. Mentor, document, and share knowledge, growing the technical capability of the team around you.
• Follow software engineering best practices in code, architecture, and testing.
• Design, build and maintain scrapers that extract data reliably from complex, JavaScript-rendered websites at scale.
• Monitor scraper health and respond quickly when target sites change structure, putting alerting and automated recovery in place where possible.
• Handle the practical demands of large‑scale collection — scheduling, throttling, session and proxy management, retries and error handling — within legal and ethical boundaries.
• Build validation into the extraction pipeline so that data quality issues are identified before they reach downstream consumers.

Requirements

• 6+ years of demonstrable JavaScript design and development experience using NestJS, ORM (object relational mapping) and js.
• Proven, hands‑on experience building production web scrapers in JavaScript, including headless browser automation with Puppeteer.
• DB knowledge is a must required, preferably Postgres which includes writing queries , query optimization.
• Hands‑on experience in building REST APIs.
• Agile Scrum experience required
• Azure Cloud experience preferred, but proven cloud experience required.
• Demonstrable experience in building software around Design Patterns
• Hands‑on experience in web sockets, microservices and message brokers
• Strong command of DOM traversal and HTML parsing using CSS selectors, XPath or libraries such as Cheerio.
• Experience handling dynamic content, infinite scroll, pagination, authentication flows and common anti‑scraping defences.
• Familiarity with proxy rotation, user‑agent and header management, request throttling and scheduled collection runs.
• Strong debugging skills, including the ability to diagnose silent scraper failures and gradual data drift.
• Ability to understand business requirements and translate them into technical requirements.
• Ability to work well with others, learn on the job, and thrive in a dynamic work environment.
• A focus on user‑oriented development, supporting services, and end‑user satisfaction.
• Excellent verbal and written communication skills.
• Familiarity with Continuous Integration/Continuous Delivery/Continuous Deployment testing, tooling, and processes.
• Experience with performance and memory tuning using different tools.
• Bachelor’s degree in Computer Science or related field, or equivalent work experience.
• Able to communicate in most of the following languages: English, French, Spanish and/or Portuguese
• Proven experience managing and coordinating with distributed teams across Europe, India, US and South Africa.

Circana Behaviors

• Stay Curious: Being hungry to learn and grow, always asking the big questions.
• Seek Clarity: Embracing complexity to create clarity and inspire action.
• Own the Outcome: Being accountable for decisions and taking ownership of our choices.
• Center on the Client: Relentlessly adding value for our customers.
• Be a Challenger: Never complacent, always striving for continuous improvement.
• Champion Inclusivity: Fostering trust in relationships engaging with empathy, respect, and integrity.
• Commit to each other: Contributing to making Circana a great place to work for everyone.

Location

This position can be located in the following area(s): France (remote) or Paris Office Spain (remote) or Madrid Office Prospective candidates may be asked to consent to background checks (in accordance with local legislation and our candidate privacy notice ) Your current employer will not be contacted without your permission.