Senior Platform Engineer

About Keystone AI (formerly HiMama) and Our Mission: At Keystone AI (formerly HiMama), we are a mission driven business with the goal of empowering early childhood educators through innovative, affordable tools that enable them to improve child outcomes, engage family members, and support continued professional growth for their staff. We are committed to serving the field as an authentic voice of the early childhood education (ECE) workforce, providing programs with all of the building blocks for high-quality early care and education and helping early educators focus on what matters most for children’s successful development and learning: relationships, play, creativity, and loving, nurturing caregiving. If you are excited about being part of an impact-driven business, focused on making a difference in the early childhood education industry, Keystone AI is the place for you. Keystone AI is a Series B, private-equity backed company and we're proud to be part of the Bain Double Impact portfolio. Keystone AI is recognized as an industry leader, most recently selected in 2025 by Time Magazine as one of the world's top EdTech companies. We’re looking for… We’re seeking a Senior Platform Engineer to join our dynamic platform engineering team. You care about system reliability, performance, security, and developer experience as much as product delivery. In this role, you’ll lead efforts to scale and improve our infrastructure, devex, and observability, while contributing across the stack when needed. You’ll help us make thoughtful trade-offs, simplify where possible, and build a platform that supports both our growth and our mission to elevate early childhood programs through high-quality software. Keystone AI Engineering At Keystone AI , our Product & Engineering teams are a tight-knit unit. By using strong product creation methodologies and processes, and by working closely together, we imagine and create great products that immediately make an impact in the lives of millions of educators, parents, and young children. The engineering team at Keystone AI is made up of full stack web engineers as well as multi-platform mobile experts. Every individual on the engineering team has the opportunity to make a big impact on growing the Keystone AI product offering with a wide and varied feature set as well as impacting how Keystone AI builds and delivers that product. From feature enhancements to the core product, ground-up engineering on brand-new architecture, data scaling, and system performance, our team strives for excellence. Engineering at Keystone AI requires being an adept problem solver that is hard working and motivated to get stuff done. *Note: we are only considering Canadian applicants for this role at this time How You’ll Make an Impact: Lead System Evolution: Drive technical decisions regarding infrastructure-as-code, CI/CD pipelines, and platform architecture to ensure long-term scalability. Operational Excellence: Lead the charge on system reliability and performance. Develop and support internal team tooling Troubleshoot, debug and resolve issues as part of a shared on-call rotation. You take an active role in ensuring the operational health and stability of the system as a whole. Mentor and support your peers, including through compassionate code review. What You Bring to the Table: Bachelor’s degree in Computer Science or equivalent experience. Ambition to work hard in order to make an impact. Evidence of independence and self-starter attitude. Collaborative, team-oriented mindset. Knowledgeable about industry best practices and emerging trends Required Technical Skills: 5+ years of software engineering/devops experience at scale Experience with AWS, RDS (Postgres), Heroku, Redis Proficiency with Terrarform, Ruby on Rails, GraphQL, React Hands-on experience with observability and reliability tools like Datadog, New Relic, Papertrail, Sentry or Prometheus to monitor system health Demonstrated technical or project leadership experience. Nice to Have: Experience with mobile app development Contributions to Open Source software Experience with current AI tooling Experience with SOC2/GDPR/ISO27001 compliance Tech stack: AWS, PostgreSQL, Heroku. Ruby on Rails, GraphQL, React Native. Note: we are only considering Canadian applicants for the position at this time. This role is posted to hire a backfill. Don’t have all the requirements but convinced you’ll be able to make an impact? We’d love to hear from you! Please note that we place serious consideration to your application responses to all questions; only completed profiles will be considered for this role. Keystone AI Perks -- Flexible working arrangements; we are a remote-first company who gathers together (virtually) every quarter, and in-person at least once per year. You must be willing to travel in-person as required for the role -- Health benefits package includes medical, dental and vision -- Paid time off, including vacation, personal and volunteer days -- Opportunities for learning, mentorship and profe