Staff Engineer

About Mixmax
At Mixmax, our mission is to eliminate busywork so that revenue teams can focus on what truly matters—engaging and serving their customers. We use AI to make customer communication seamless and proactive. Since our launch in 2015, over 10,000 Sales and Customer Success teams trust Mixmax to streamline their workflows and deliver flawless customer experiences.

The Opportunity
We’re looking for a Staff Software Engineer to lead complex initiatives, own systems end-to-end, and shape the future of our platform. This is a high-impact role for a strategic thinker and builder who can combine technical depth, product intuition, and cross-functional influence.

You will be instrumental in scaling our architecture, defining engineering standards, and applying AI in pragmatic, product-driven ways. You should thrive in fast-paced, ambiguous environments and bring a strong sense of initiative, ownership, and adaptability. We’re a startup—things change fast. We’re looking for someone who finds energy in that.

Note: We are only hiring candidates located in Europe or Latin America at this time.

What You’ll Do
As a Staff Engineer at Mixmax, you’ll be expected to:

• Lead architectural decisions for highly scalable, event-driven backend services

• Drive technical strategy and mentor engineers across teams

• Set quality standards and champion best practices for reliability, performance, and code health

• Design and evolve core systems using Node.js, TypeScript, MongoDB, and AWS

• Collaborate with product, design, and leadership to define and deliver roadmap priorities

• Integrate AI and LLMs into product experiences in a way that is user-centric and technically sound

• Contribute to a strong, distributed engineering culture focused on autonomy, curiosity, and impact

What Success Looks Like

In your first 3 months:

• Deeply understand our domain, codebase, and AI ambitions

• Ship major system improvements or features, grounded in architectural clarity

• Identify key technical risks or inefficiencies and propose solutions

• Influence roadmap conversations through a combination of technical insight and product thinking

In your first 6 months:

• Lead a critical, cross-team engineering initiative

• Formalize patterns, frameworks, or internal tooling to raise the bar across engineering

• Drive AI experimentation and implementation that directly improves user outcomes

• Act as a trusted advisor to both engineers and leadership

What We’re Looking For

• 10+ years of backend engineering experience (including 2+ years at Staff+ level)

• Deep expertise in Node.js, TypeScript, MongoDB, AWS, and distributed systems

• Proven experience leading architecture for scaled SaaS products

• A strong product mindset—you think in terms of impact, not just implementation

• Excellent written and verbal communication skills in remote settings

• Adaptability, resilience, and comfort working through ambiguity and complexity

• Experience mentoring engineers and guiding teams through change and growth

Bonus: AI & LLM Expertise
You don’t need to be a machine learning expert, but we’re looking for someone who can drive practical applications of AI in a user-facing product. This includes:

• Integrating LLM APIs (e.g. OpenAI, Claude) to build intelligent features

• Designing and refining prompts for performance and consistency

• Evaluating trade-offs in model selection, latency, and cost

• Debugging and tuning prompt behavior, possibly using RAG techniques

• Staying ahead of AI trends and finding new ways to apply them meaningfully

Why Join Mixmax?

• High ownership and influence in a fast-moving, product-led environment

• Competitive salary, meaningful equity, and great benefits

• A remote-first team with a thoughtful async culture

• A chance to build what’s next in AI-powered productivity

Our Hiring Commitment
We know that no one fits every bullet point. What matters most is your depth of experience, your clarity of thought, and your drive to make an impact. If you're excited about this opportunity and believe you can bring value to the role, we encourage you to apply—even if you’re not sure you meet every single requirement.