Junior JavaScript Developer

Are you passionate about JavaScript development, integrations, and solving complex technical challenges in customer-facing environments? We are looking for a Junior JavaScript Developer to join a dynamic AdTech project focused on behavioral analytics and marketing automation.
At Sigma Software, you will work on scalable integrations connecting websites, marketing platforms, and real-time customer engagement systems. This role combines Front-end development, API integrations, troubleshooting, and collaboration with international teams.
We as a company offer a supportive engineering culture, opportunities for professional growth, and the chance to work with modern AdTech and marketing automation technologies while contributing directly to Customer success.

Customer
Our partner is a fast-growing AdTech company helping brands identify and engage anonymous website visitors through behavioral intelligence and marketing automation. The platform transforms browsing behavior into actionable insights, enabling personalized campaigns across email, SMS, and paid advertising channels. The solution supports businesses in improving conversion rates, customer engagement, and revenue growth through scalable data-driven marketing strategies.

Project
The project focuses on developing and maintaining integrations between the AdTech platform and customer ecosystems, including websites, Email Service Providers, and marketing automation tools. The team delivers behavioral tracking solutions, onboarding processes, real-time event pipelines, and personalized onsite experiences for international customers.
You will participate in integration development, technical troubleshooting, migration activities, and implementation of custom JavaScript solutions for marketing campaigns and data synchronization workflows.

Responsibilities
Configure and maintain website integrations, including event tracking, SPA fixes, cart tracking, and catalog integrations
Implement and support Email Service Provider integrations and synchronization workflows
Execute migration and replatforming activities with comprehensive validation and testing
Develop custom onsite JavaScript solutions for campaigns and interactive user flows
Build and support Airflow DAGs for recurring data processing workflows
Configure dynamic email content and SKU-level recommendation tracking
Analyze Customer requests and assess technical feasibility of solutions
Develop integrations with third-party marketing and email platforms
Investigate and resolve production issues and perform root cause analysis
Collaborate with account managers, QA engineers, and implementation specialists
Participate in technical consultations and onboarding alignment meetings

Requirements
2+ years of commercial experience with Vanilla JavaScript (ECMAScript 5+)
Strong knowledge of HTML and CSS
Hands-on experience with REST API integrations
Practical experience with jQuery
Experience with Chrome DevTools and browser debugging
Understanding of behavioral event tracking implementation
Knowledge of Email Service Provider integration workflows
Ability to develop custom JavaScript logic for onsite experiences
Strong analytical and problem-solving skills
Good communication skills with technical and non-technical stakeholders
Attention to detail and commitment to code quality
Experience working in cross-functional teams
Intermediate+ English level
Readiness to learn new tools and domain-specific technologies

WILL BE A PLUS
Experience with PHP
Familiarity with Apache Airflow
Experience using Postman
Understanding of Git workflows
Experience with AdTech or marketing technology platforms
Exposure to Customer-facing onboarding or integration projects

PERSONAL PROFILE
Proactive and solution-oriented mindset
Strong ownership and accountability
Ability to work independently and collaboratively
Detail-oriented approach to testing and troubleshooting
Comfortable working in a fast-paced environment
Strong communication and stakeholder management skills