Senior Software Development Engineer for Machine Learning

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. 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.
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. 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. 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.
React.js / TypeScript · Python · GoLang · MongoDB · Elasticsearch · Redis · Kafka · Kubernetes / Docker · GCP · Terraform / Ansible · Grafana / Kibana · GitHub Actions
Design and implement highly scalable backend services, data pipelines, and integration endpoints that perform reliably at high volume
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
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 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
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
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
Experience with database modeling (SQL or NoSQL)
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
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
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
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.

At Apollo, we’re driven by a shared mission: to help our customers unlock their full revenue potential. 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.