Sr. Software Engineer, Messaging Infrastructure

Klaviyo; Dublin; On-site; EUR 92,000 - 138,000; Full time

Benefits offered by this job

Comprehensive health and wellbeing benefits

Annual cash bonus plan

Equity options

Job summary

Klaviyo in Dublin, Ireland is looking for a skilled Software Engineer to help build and enhance features for our marketing automation platform. The ideal candidate has 4-6+ years of experience in software engineering, enjoys driving innovation, and has experience with performance optimization.

You'll collaborate with cross-functional teams and mentor junior engineers while working in a hybrid environment. We support work authorization and relocation for this position.

Competitive salary ranges from €92,000 to €138,000 based on relevant experience.

Qualifications

• 4-6+ years of experience in software engineering, with at least one complex system delivered.
• Experience in large-scale system architecture and technology trade-offs.
• Proven coach and mentor for team members.

Responsibilities

• Own and build features that customers rely on.
• Collaborate with teams on designs and implementations.
• Participate in the technical interview process.

Skills

Software engineering

System architecture

Performance optimization

Coaching and mentoring

Collaboration

Education

Relevant computer science degree

Tools

Python

Django

React

AWS

Terraform

Job description

At Klaviyo, we value the unique backgrounds, experiences and perspectives each person brings to our workplace each and every day. We believe everyone deserves a fair shot at success and appreciate the experiences each person brings beyond the traditional job requirements. If you are a close but not exact match with the description, we hope you will still consider applying. Learn more about life at Klaviyo.

About Klaviyo

Klaviyo is a leading marketing automation platform that helps businesses grow by delivering personalized experiences. Our mission is to empower creators to own their destiny. We believe in providing an exceptional developer experience that enables our engineering teams to build and ship high-quality software efficiently and with confidence.

About the Team

The Messaging Infra organization at Klaviyo is focused on high‑growth customer engagement through various messaging channels (email, SMS/MMS/RCS, mobile push, WhatsApp, and more). We work with multiple stakeholders to provide best‑in‑class service and reliability to connect a wide range of businesses, from entrepreneurs to enterprises, with their end users. The messaging platform is a mission‑critical system, responsible for delivering billions of messages, and must be architected for massive scale and reliability.

How You Will Make a Difference

• Own and build features and services that hundreds of thousands of Klaviyo customers rely on daily to drive their business forward.
• Work on crafting our highly scalable and available campaign pipeline that processes and delivers hundreds of millions of messages daily and grows to billions scale.
• Collaborate radically with teams and stakeholders across Klaviyo on designs, implementations, and engineering practices.
• Learn new technologies, bring them to the team and apply them to evolve our systems to the next level.
• Help us improve our experimentation and development processes, and mentor other engineers on the team.
• Participate in the technical interview process to help maintain a high bar for our growing teams.
• Contribute as a subject‑matter expert, constantly pushing yourself to be a better engineer and to level up your peers within your team and within Klaviyo.

Who You Are

• Have 4-6+ years of experience in software engineering and have architected, built and delivered at least one complex system.
• Experience in large‑scale system architecture, technologies and patterns; understand their pros and cons and use scenarios, and can make appropriate tradeoffs to meet business needs.
• Love digging into performance and scalability issues to drive breakthrough solutions – whether a performance degradation, bottleneck, or slow query.
• Passionate about growing and improving a product daily using a data‑driven mindset, familiar with system monitoring and alerting techniques.
• Proven experience as a coach and mentor for team members and helping them grow.
• Enjoy working on small, high‑performing autonomous agile teams; own features while collaborating radically with everyone to produce the right solution.

Technologies we use (not exhaustive)

Languages & Frameworks: Python, Django, React

Data & Infrastructure: MySQL, Redis, Memcached, Apache Zookeeper, Apache Pulsar

Cloud & DevOps: AWS (EC2, RDS, Aurora), Terraform, Jenkins

Location & Work Model

This role is based in Dublin, Ireland and follows a hybrid working model. Klaviyo supports work authorization and relocation for this position.

Travel may be required up to 10% for purposes such as new hire onboarding, client or partner work if applicable, team meetings, and industry events. Travel is coordinated in advance.

Salary Range

The base salary offered for this position is determined by several factors, including the applicant’s job‑related skills, relevant experience, education or training, and work location. In addition to base salary, the total compensation package may include participation in the company’s annual cash bonus plan, variable compensation for sales and customer success roles, equity, sign‑on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility.

Base Pay Range in Local Currency: €92.000 – €138.000 EUR

Equal Opportunity Employment

Klaviyo is committed to a policy of equal opportunity and non‑discrimination. We do not discriminate on the basis of race, ethnicity, citizenship, national origin, color, religion or religious creed, age, sex (including pregnancy), gender identity, sexual orientation, physical or mental disability, veteran or active military status, marital status, criminal record, genetics, retaliation, sexual harassment or any other characteristic protected by applicable law.

We are committed to building inclusive teams and encourage applications from candidates of all backgrounds.

AI fluency at Klaviyo includes responsible use of AI (privacy, security, bias awareness, and human‑in‑the‑loop). We provide accommodations as needed.