Senior Software Engineer

Apollo.io is the leading go-to-market solution for revenue teams, trusted by over 500,000 companies and millions of users globally, from rapidly growing startups to some of the world's largest enterprises. Founded in 2015, the company is one of the fastest growing companies in SaaS, raising approximately $250 million to date and valued at $1.6 billion.  Apollo.io provides sales and marketing teams with easy access to verified contact data for over 210 million B2B contacts and 35 million companies worldwide, along with tools to engage and convert these contacts in one unified platform. By helping revenue professionals find the most accurate contact information and automating the outreach process,  Apollo.io turns prospects into customers. Apollo raised a series D in 2023 and is backed by top-tier investors, including Sequoia Capital, Bain Capital Ventures, and more, and counts the former President and COO of Hubspot, JD Sherman, among its board members.

YOUR ROLE & MISSION

As a Senior Software Engineer, you will be a critical part of our growing company, working on a cross-functional team to implement best practices in technology, architecture, and process. You’ll have the chance to work in an open and collaborative environment, receive and give hands-on mentorship, and have opportunities to grow and accelerate your career. You love both learning and teaching.

In this role, you will work across two high-impact domains: data platform architecture and integrations with distributed systems building the infrastructure that powers Apollo’s AI-driven internal products. On the data side, you’ll organize and make sense of data at scale, working closely with our data engineering team to structure pipelines and enable intelligent product experiences. On the integrations side, you’ll own the connections layer and the distributed architecture that keeps Apollo reliably linked to the broader ecosystem at high throughput.

You enjoy working cross-functionally to solve hard problems and make an impact. At Apollo, you strive for quality and are obsessed with improving automation, squashing bugs, and investigating performance improvements and innovative ideas. You bring an AI-first mindset to everything you do, reaching for AI tools as naturally as any other part of your workflow and helping the team do the same.

Our tech stack:   React.js / TypeScript · Python · GoLang · MongoDB · Elasticsearch · Redis · Kafka · Kubernetes / Docker · GCP · Terraform / Ansible · Grafana / Kibana · GitHub Actions

DAILY ADVENTURES & RESPONSIBILITIES

• Design and implement highly scalable backend services, data pipelines, and integration endpoints that perform reliably at high volume

• Gather product and engineering requirements; write design documents and drive technical discussions to align cross-functional stakeholders

• Drive and lead the full software development lifecycle: product requirements, architecture, solution design, development, quality assurance, and maintenance

• Build systems with observability as a first-class concern proper monitoring, alerting, and dashboards so issues are caught before customers notice

• Mentor others on best practices and effectively share knowledge across the engineering team

• Communicate development progress clearly to product leads, engineering managers, and other stakeholders

• Be comfortable introducing new technologies and new ideas as required, including AI tools that accelerate your workflow and the team’s

• Navigate ambiguity and roadblocks proactively when a project hits a wall, you find a path forward and maintain cadence

• Work effectively as part of a large global team, attending scrum ceremonies, team events, and manager 1:1s

• Provide and respond to technical and behavioral feedback from managers and peers in written and verbal form

COMPETENCIES

• Proactively acts without being told what to do; identifies areas for improvement and drives best practices to deliver high-quality, performant, and scalable solutions

• Develops services that are highly available and scalable with proper monitoring and alerting in place

• Able to up-level the team by sharing knowledge and best practices across the engineering organization

• Able to deal with ambiguity and maintain momentum on projects even when hitting obstacles months in

• Full ownership of projects from start to finish because deployment is not the finish line

• Organized and able to effectively plan and break down large projects into smaller tasks that are easier to estimate and deliver

• Listens actively and seeks to understand others’ viewpoints before responding

• A creative and innovative problem solver with previous experience working in an agile, startup environment

• Confident in owning your role and bringing creative ideas to the hands of users

• AI-native working style: habitually leverages AI tools across coding, debugging, review, and documentation, and stays current with emerging capabilities

QUALIFICATIONS

• Minimum 5 years  of industry experience in backend development, at least 1-2 years in senior positions, developing large-scale applications

• Experience developing distributed web applications at scale

• Code that is comprehensible, well-structured, and highly performant

• Experience with database modeling (SQL or NoSQL)

• Experience using and designing RESTful services

• Strong knowledge of computer science fundamentals, including data structures, algorithms, and object-oriented design

• Proven experience leveraging AI tools to enhance software development processes, including code generation, debugging, and productivity optimization, with a willingness to stay current with emerging AI technologies

• Background in fast-scaling startup or high-velocity environments where going beyond your job title was the norm

Must have:  Communication Skills, Problem Solving, Proactivity, Team Player, Listening Skills, Creativity and Innovation, Organization and Planning, Dealing with Ambiguity, Ownership of projects from start to finish, Distributed Web Development

Nice to have: BS or MS degree in Computer Science, Computer Engineering or similar, GCP, Kubernetes, Docker, Mongo, Redis, Ruby on Rails, Microservices, Machine Learning

We are AI Native

Apollo.io is an AI-native company built on a culture of continuous improvement. We’re on the front lines of driving productivity for our customers—and we expect the same mindset from our team. If you're energized by finding smarter, faster ways to get things done using AI and automation, you'll thrive here.

Why You’ll Love Working at Apollo

At Apollo, we’re driven by a shared mission: to help our customers unlock their full revenue potential. That’s why we  take extreme ownership of our work,  move with focus and urgency , and  learn voraciously to stay ahead.

We invest deeply in your growth, ensuring you have the resources, support, and autonomy to  own your role and make a real impact . Collaboration is at our core—we’re  all for one , meaning you’ll have a team across departments ready to help you succeed. We encourage  bold ideas and courageous action , giving you the freedom to experiment, take smart risks, and drive big wins.

If you’re looking for a place where your work matters, where you can push boundaries, and where your career can thrive—Apollo is the place for you. 

Learn more  here!