Threecolts

Junior Full Stack Developer (.Net/Vue.JS)

Location: Remote (Hybrid – Kyiv)
Salary: $1,500 USD per month 
 

About Threecolts

Threecolts is a high-growth SaaS company supporting thousands of Amazon and Walmart sellers with powerful tools for growth, automation, and insight. With a global team of 500+ across 40+ countries, we’re remote-first, product-led, and building systems that process millions of data points every day.

The role

ExportYourStore is one of our leading products—an eCommerce automation platform that helps sellers manage and sync their inventory across major marketplaces like Amazon, eBay, Shopify, TikTok, Etsy, Walmart, and more. We simplify multichannel selling, enabling merchants to scale faster with less manual effort.

What You’ll Do

• Maintain and enhance our existing .NET codebase
• Develop new features that improve the platform experience
• Build and manage integrations with major eCommerce marketplaces
• Support our migration to a modern tech stack
• Join planning sessions and contribute to feature scoping and estimation

What We’re Looking For

• At least 1 years experience in a similar role
• Solid understanding of .NET and C#
• Experience with at least one front-end framework: React, Angular, or Vue
• Strong grasp of OOP and SOLID principles
• Good knowledge of HTTP and RESTful APIs
• Hands-on experience with SQL databases

Nice-to-Have

• Familiarity with GraphQL
• Experience with Entity Framework 6 or EF Core
• Experience with ASP.NET Core

What We Offer

• Fully remote work for now
• Hybrid setup planned (Kyiv office)
• Flexible working hours
• Collaborative, supportive team culture
• Exposure to modern technologies and scalable architecture
• Opportunity to shape product features and influence decisions

Backend Engineer – Java / Data SystemsLocation:

Remote (Poland/EU) Contractor

Salary: $60,000

About Threecolts

Threecolts is a global software powerhouse for marketplace sellers and e-commerce brands. We help Amazon, Walmart, and multichannel operators scale through our suite of 24+ best-in-class SaaS tools — all available through our bundled solution, Seller 365. With a presence across 42 countries and a mission to support seller success, we're growing fast and hiring smarter.

About the RoleWe’re looking for a Backend Engineer to build and scale high-performance Java services that process massive data volumes, integrate with external systems, and run reliably in production. You’ll work on high-QPS systems, scraping pipelines, and cloud-native infrastructure.

Responsibilities

• Design, develop, and optimize backend services in Java (Spring Boot)
• Build and maintain scalable, concurrent scraping systems (Selenium / Playwright)
• Implement caching, async messaging, and streaming using Redis and Kafka
• Optimize PostgreSQL queries for high-throughput workloads
• Parse and process data from multiple sources and file formats
• Deploy, monitor, and maintain applications on Kubernetes and AWS (EC2, EKS, RDS, S3)
• Tune JVM performance and ensure system scalability
• Set up monitoring, metrics, and alerts using Prometheus and Grafana
• Troubleshoot and improve system reliability and infrastructure

Requirements

• Strong Java (Spring Boot) backend development
• PostgreSQL: query optimization, high-throughput environments
• Redis & Kafka for caching and async messaging
• Build concurrent scraping systems (Selenium / Playwright)
• Multithreading, parallel/multiprocessing, async comms
• Parse and process multiple file types (HTML, PDF, CSV, XLS, DOC, Parquet, etc.)
• Deploy & manage apps in Kubernetes (stateless & stateful)
• AWS: EC2, EKS, RDS, S3
• JVM tuning & performance optimization
• Large-scale data transformation/processing
• Monitoring & alerting with Prometheus and Grafana
• Kubernetes infrastructure troubleshooting

Nice to Have

• Node.js, TypeScript, Python
• Scraping anti-bot strategies
• AI/LLM-based automation & data processing