FreJun Tech Stack

Voice and WhatsApp platform for outbound sales and recruiting calls

Desktop Computing Software Products Seattle, Washington 11–50 employees Founded 2019 Privately Held

FreJun operates a real-time voice and messaging platform built on WebRTC, SIP, and Node.js + Python backends, with infrastructure spanning RabbitMQ, Kubernetes, and AWS. The tech stack reveals a company scaling distributed systems for voice workflows—evident in active projects around real-time STT/TTS/LLM pipelines and API lifecycle management. Pain points cluster around geographic scaling and system reliability, suggesting FreJun is moving beyond single-region deployments.

Tech Stack 31 technologies

Core StackHubSpot Salesforce Node.js Python RabbitMQ AWS Docker Linux PostgreSQL Go Playwright Selenium Cypress Postman Kubernetes VMware Jenkins Jira Confluence Ahrefs SurferSEO SEMrush WebSockets SIP pytest REST Assured Git WebRTC

What FreJun Is Building

◆Challenges

Improving content seo performance
Increasing serp visibility
Boosting content engagement
Scaling real-time systems
Optimizing performance
Heavy load
Scaling voice workflows across geographies
Reducing developer friction
Ensuring reliability at scale

▲Active Projects

Long-form blog series on ai and call automation
Internal linking framework for topical authority
Content performance tracking dashboard
Scalable backend services
Real-time communication platform
Distributed system architecture
Design real-time stt/tts/llm pipelines
Build scalable api lifecycle workflows
Test new model combinations

Hiring Activity

Minimal6 roles · 0 in 30d

Department

Engineering

Marketing

Product

Sales

Seniority

Mid

Senior

Junior

Lead

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About FreJun

FreJun builds a calling and WhatsApp platform for outbound sales outreach and recruiting workflows. The product sits at the intersection of telephony (SIP, WebRTC) and messaging, serving teams who need to conduct conversations at scale across voice and text. Founded in 2019 and based in Seattle, FreJun operates with a lean 11–50-person team distributed across engineering, product, sales, and marketing. The engineering-focused hiring pattern and active backend/distributed-systems work suggest the company is deepening platform capabilities rather than broad feature expansion.

HeadquartersSeattle, Washington

Company Size11–50 employees

Founded2019

Hiring MarketsIndia

Frequently Asked Questions

What tech stack does FreJun use?

FreJun's stack includes Node.js, Python, and Go for backend services; WebRTC and SIP for voice; PostgreSQL for persistence; RabbitMQ for messaging; Kubernetes for orchestration; and AWS for hosting. Testing is covered by Playwright, Selenium, Cypress, and pytest.

What is FreJun working on?

Current projects include real-time STT/TTS/LLM pipeline design, scalable backend services, distributed system architecture, and API lifecycle workflows. Content marketing efforts focus on AI and call automation topics.