Senior Backend Engineer – AI Agents

About Modlix AI Modlix AI is an AI-powered no-code platform and Marketing & Sales Operating System built specifically for small and medium businesses (SMBs) globally. The platform helps businesses manage their online presence, marketing campaigns, customer relationships, lead generation, and growth initiatives through a single connected ecosystem. At Modlix AI, we are building AI-native revenue infrastructure that enables businesses to qualify, engage, nurture, and convert leads at scale using intelligent AI systems. Our AI agents perform real business functions—qualifying leads, making voice calls, scheduling meetings, conducting market research, analyzing competitors, assisting sales teams, and driving measurable revenue outcomes. This is not a maintenance role. This is a high-ownership engineering opportunity for someone who wants to work at the cutting edge of AI, Voice AI, Agentic Systems, and Revenue Automation.

The Role We are looking for a Senior Backend Engineer to architect, build, and scale AI agents for Modlix AI's platform. You will work on agentic systems that combine LLMs, voice models, backend systems, workflows, integrations, memory, tools, and business logic. These agents will operate across sales, marketing, customer engagement, and revenue-generation use cases while directly impacting business outcomes for our customers. You will be expected to own technical decisions, move fast, build deeply, and ship production-grade systems in a high-growth startup environment.

What You Will Own

• Architect and build AI agents for sales, marketing, lead qualification, voice calling, meeting scheduling, market research, and competitor intelligence.
• Design reliable backend systems that allow agents to reason, act, use tools, and complete business workflows.
• Build and scale integrations using MCP servers, APIs, internal tools, and custom backend services.
• Work with LLMs, voice models, prompts, workflows, orchestration layers, and evaluation systems.
• Create streamlined processes to train, configure, test, and deploy agents across customer use cases.
• Own performance, reliability, security, observability, and scalability of agent systems.
• Collaborate closely with Product and Design teams to define user interactions with AI agents.
• Drive technical decisions from architecture through production deployment.
• Contribute to the engineering culture, technical roadmap, and long-term AI platform strategy.

What We Are Looking For

• 5+ years of software engineering experience, preferably in backend-heavy roles.
• Strong experience with Python and building scalable backend applications.
• Prior experience building LLM-based applications; experience with AI agents is a strong plus.
• Working knowledge of LLMs, voice models, prompt workflows, tool calling, and agent orchestration.
• Strong understanding of system design, APIs, distributed systems, queues, background jobs, and production reliability.
• Experience with relational databases such as MySQL and NoSQL databases such as MongoDB.
• Experience with AWS services and cloud-native architecture.
• Ability to build rapidly without compromising reliability, security, and maintainability.
• Strong problem-solving skills and comfort working in ambiguous environments.
• High ownership mindset with the ability to drive projects from idea to production.

You Will Thrive Here If

• You want to build real AI products, not just wrappers around APIs.
• You enjoy working in fast-paced startup environments.
• You are excited by AI agents, Voice AI, automation, and applied LLM systems.
• You like owning problems end-to-end and delivering outcomes.
• You care deeply about business impact and customer value.
• You enjoy collaborating closely with founders, product teams, and customers.
• You are comfortable with speed, change, and high standards.

Good to Have

• Experience with LangChain, LlamaIndex, CrewAI, AutoGen, OpenAI, Anthropic, Gemini, or similar ecosystems.
• Experience building Voice AI workflows using ElevenLabs, Deepgram, Twilio, OpenAI Realtime, or similar technologies.
• Experience with MCP servers, tool calling, RAG, embeddings, vector databases, evaluations, and agent memory.
• Experience in SalesTech, MarTech, CRM, lead qualification, or revenue automation products.
• Experience working in early-stage or high-growth startups.

Why Join Modlix AI

• Build AI agents that solve real-world sales, marketing, and revenue challenges.
• Work directly with founders and a highly driven engineering team.
• Gain deep exposure to LLMs, Voice AI, Agentic Systems, and Revenue Automation.
• Solve challenging engineering and product problems with significant ownership.
• Be part of a company building the future of AI-powered business growth infrastructure. Keywords AI Agents, Backend Engineer, Python, LLM, Voice AI, Agentic AI, OpenAI, MCP, LangChain, AWS, MySQL, MongoDB, SaaS, Sales Automation, Marketing Automation, Revenue Intelligence, GTM, Startup Engineering.