Sigma Software Group

Middle Full-Stack Software Engineer – AI Voice Systems

Sigma Software Group  •  Lviv, UA (Onsite)  •  4 days ago
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Job Description

We are looking for a Middle Full-Stack Software Engineer with strong experience in TypeScript, React/Next.js, and solid working knowledge of backend development with Python

The ideal candidate is comfortable owning features end to end — from frontend implementation and user-facing flows to backend services, APIs, integrations, and production support. This role is a good fit for an engineer who enjoys working across the stack, solving complex integration challenges, and contributing to a product in the AI communication space.

The position is slightly frontend-leaning, but still requires the ability to read, write, and maintain backend services.

CUSTOMER

The customer is a product company developing a platform for automating customer communications using AI-based solutions.

The team is small, fast-scaling, and operates with a low level of bureaucracy. The role involves direct communication with the customer team and a strong ownership-oriented engineering culture.

The project is in an active development phase. The candidate will work on frontend features, backend services, external provider integrations, and contribute to the ongoing development of the existing platform.

PROJECT

The project is an agentic call center platform that uses Voice and Text AI agents to conduct real customer conversations, automate workflows, and integrate with CRMs and telecom providers.

The platform helps businesses automate customer communication at scale, including bookings, call transfers, CRM workflows, messaging, and routing.

From a technical perspective, the project is interesting because it includes frontend development with React/Next.js, backend services in Python, GraphQL APIs, real-time voice AI workflows, integrations with external providers, MongoDB, Aurora, RabbitMQ, Redis, Docker/ECS, and a future migration toward Kubernetes.

Key Technologies

TypeScript, React, Next.js, GraphQL, Apollo, Python, MongoDB, Aurora / PostgreSQL, RabbitMQ, Redis, Docker, ECS, Kubernetes, AWS, AI/LLM integrations, real-time voice AI.

  • Develop and maintain full-stack features in a production environment.
  • Build user-facing functionality using TypeScript, React, and Next.js.
  • Work with server-side rendering and general Next.js patterns.
  • Build, consume, and maintain GraphQL APIs, ideally using Apollo.
  • Read, write, and maintain backend services in Python.
  • Contribute to API design, data modeling, and service-to-service communication.
  • Support integrations with CRMs, telecom providers, and AI-related vendors.
  • Work with MongoDB and Aurora / PostgreSQL for data storage.
  • Participate in debugging across the stack — from browser DevTools to backend logs.
  • Work with Docker and containerized deployments.
  • Contribute to CI/CD improvements, deployment safety, logging, monitoring, and observability.
  • Help keep production services stable, reliable, and easy to support.
  • Communicate directly with the customer team and take ownership of tasks from start to finish.

Qualifications

  • 3+ years of full-stack engineering experience, preferably with a frontend focus.
  • Experience owning features end to end in a production environment.
  • Good working knowledge of TypeScript.
  • Strong experience with React and Next.js.
  • Familiarity with server-side rendering and general Next.js patterns.
  • Experience working with GraphQL, ideally Apollo.
  • Ability to build and consume GraphQL APIs.
  • Comfortable working with Python: able to read, write, and maintain backend services.
  • General understanding of backend fundamentals: API design, data modeling, and how services communicate with each other.
  • Experience with Docker and containerized deployments.
  • Experience with MongoDB or a relational database such as PostgreSQL / Aurora.
  • Understanding of basic schema design and ability to write reasonable queries.
  • Ability to debug across the stack, from frontend issues to backend logs.
  • Interest in production topics: logging, monitoring, reliability, and service health.
  • Proactive communication and ability to take a task and drive it without constant hand-holding.
  • Comfortable working in a small team with direct customer communication.

WILL BE A PLUS

  • Experience with Python backend services in production.
  • Exposure to messaging systems such as RabbitMQ or similar tools.
  • Experience with Redis or other caching tools.
  • Experience with real-time systems: telephony, WebSockets, streaming, low-latency pipelines.
  • Familiarity with vendor orchestration patterns: fallback routing, provider selection.
  • Any Kubernetes experience, even in dev/staging environments.
  • Experience with AI/LLM, TTS/STT, or voice-related systems.
  • Exposure to security/compliance concepts: SOC 2, secrets management, audit trails.

Additional Information

PERSONAL PROFILE

  • Proactive and ownership-driven mindset.
  • Comfortable working across frontend and backend.
  • Enjoys solving complex product and integration challenges.
  • Interested in AI-driven communication products.
  • Strong problem-solving skills.
  • Effective communicator in distributed and small teams.
  • Able to work independently and clarify requirements when needed.
Sigma Software Group

About Sigma Software Group

Sigma Software Group, an award-winning and trusted IT partner, has been serving customers for over 22 years, providing comprehensive IT solutions to various businesses, ranging from startups to established software product houses. As one of Europe's substantial IT consultancies, it brings together a dedicated workforce of over 2,100 professionals in 40 offices across 19 countries. With a diverse client base, including more than 300 enterprises, including Fortune 500 stalwarts, Sigma Software Group is a preferred choice for developing solutions that help businesses create cutting-edge products while meeting their unique needs.

Sigma Software Group operates as a dynamic ecosystem of tech companies, offering 25 ready-to-implement innovative products and 40+ value-added services. Furthermore, Sigma Software Group is committed to fostering innovation through initiatives such as the Sigma Software Labs business incubator, Sigma Software University, the SID Venture Partners VC Fund, UA Tech Network, Techosystem, the European Business Association, and other collaborative efforts.

Since 2015, Sigma Software Group has consistently earned recognition on the IAOP's prestigious World's Top 100 Outsourcing list. The company's accomplishments have also been acknowledged by prominent global media outlets such as Forbes, CNBC, The Times, and Reuters.

Industry
IT & Software
Company Size
1,001-5,000 employees
Headquarters
Stockholm, SE
Year Founded
2002
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