Software Engineer, Infrastructure (Optimization)
About this role
Built with intelligent tools such as AI and Automation, no code-configuration and a connected data platform that unifies data from multiple sources through a single timeline, Kustomer empowers businesses to operate with greater efficiency and deliver more personalized service to customers across any channel, making every interaction more meaningful and memorable. Today, Kustomer is the core platform for some of the leading customer service brands like Sweetgreen, Starz, Vuori, Resy and Cotopaxi.Kustomer was founded in 2015 by serial entrepreneurs Brad Birnbaum and Jeremy Suriel and has raised over $230M in funding backed by leading VCs. Meta announced its intention to acquire Kustomer in 2020 and completed the transaction in 2022. Kustomer joined Meta’s Business Messaging Group to transform the way people and businesses communicate through modern messaging channels.In 2023, Kustomer spun out from Meta as a standalone company backed by original partners, Battery, Redpoint and Boldstart Ventures, who have invested $60M. In 2025, Kustomer announced a $30M Series B led by Norwest, with continued support from Battery, Redpoint, and boldstart. This milestone reflects strong conviction in our vision and fuels our next chapter of growth: expanding our AI-native platform, accelerating product innovation, and scaling our exceptional team.Our Krew is made up of passionate and collaborative people who really care about what they do and the people they help. We look for people who are passionate about enhancing the customer service experience for everyone involved, as it's the core of what we do. We're growing our business with no plans of slowing down. We actively seek individuals who want to learn and be challenged every day. We have also transitioned to a remote friendly company, with Krew members located throughout the U.S. and U.K. coming together for Kamp Kustomer each year.About the RoleKustomer is looking for an Infrastructure Engineer to own cost optimization across our cloud and AI infrastructure. This role is mostly focused on driving down our AWS/infra and AI token spend, while keeping an eye on the AI tooling ecosystem that powers our platform. You'll sit on our Foundation team, partnering closely with engineering leadership to find, prioritize, and execute cost-saving initiatives without sacrificing performance or reliability.If you love digging into a cost and usage report, right-sizing EC2 fleets, negotiating reserved capacity, or figuring out why an LLM call is burning 3x the tokens it needs to; this role is built for you.This is a chance to own cost optimization as a function end to end; you'll set the strategy, build the tooling, and see it through from idea to impact.What You'll DoInfrastructure & Cloud Cost OptimizationOwn AWS cost optimization end-to-end: EC2 right-sizing, Reserved Instances/Savings Plans, spot usage, storage tiering, and unused resource cleanupBuild dashboards and reporting to track infra spend by team/service, and flag anomalies before they become expensivePartner with engineering teams to identify and eliminate waste, think idle resources, over-provisioned instances, redundant environmentsDrive architectural decisions that balance cost, performance, and reliabilityUse Terraform to codify and enforce cost-conscious infrastructure standardsAI Token Spend OptimizationAnalyze and reduce AI/LLM token spend across our AI-native platform, model right-sizing, prompt efficiency, caching, and routing strategiesWork with our Foundations team on developer tooling to build guardrails and observability around token usageEvaluate deterministic vs. generative tool selection tradeoffs from a cost lens, and recommend where cheaper approaches can do the same jobSupport Kustomer's AI capabilities (Architect, Concierge, Envoy) by keeping them performant and cost-efficientCross-Team CollaborationReport on cost trends and savings opportunities directly to engineering leadershipProactively identify systemic inefficiencies and build the tooling to keep them from creeping backCollaborate with FinOps/finance stakeholders to forecast and track spend against budget, while driving alignment across engineering teams that balances developer input without sacrificing speed and momentumOur Tech StackAWS Cloud (EC2, and the broader AWS cost/billing tooling), TerraformMongoDB, Redis, Elasticsearch, ClickhouseKafka, KinesisGo, Python, JavaScript (React/Node.js)Your Qualifications and ExperienceBachelor's degree in Computer Science, Computer Engineering, a relevant technical field, or equivalent practical experience4+ years of experience with AWS infrastructure at scale, with a strong track record of driving down cloud costsHands-on experience with AWS cost tools (Cost Explorer, Cost and Usage Reports, Trusted Advisor, etc.) and EC2 right-sizing/reservation strategiesProficiency with Terraform or other Infrastructure as Code tools, and a high-level programming language such as Go, Python, or JavaScriptFamiliarity with LLM/AI infrastructure cost drivers (token usage, model pricing, caching strategies) is a strong plusYou think in dollars saved, not just tickets closedCurious what AI-native CX looks like in practice? Check out Kustomer's Co-founder ant CTO Jeremy Suriel's recent conversation on CX Now for a look at how we build AI into our platform.HIPAA ComplianceAll roles at Kustomer may involve handling sensitive personal data.BenefitsKustomer offers an array of benefits including competitive salaries and stock options. In the U.S. we offer 100% healthcare coverage, 401K, WiFi and Mobile reimbursement, and a generous vacation policy; in the UK we also offer pension, supplemental health insurance and other perks.Diversity & Inclusion at KustomerKustomer is committed to bringing together individuals from different backgrounds and perspectives.We strive to create an inclusive environment where everyone can thrive, feel a sense of belonging, and do great work together.We are proud to be an equal opportunity employer open to all qualified applicants regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or expression, Veteran status, or any other legally protected status.Candidate Privacy NoticeAs a job applicant, you have the right to know and understand the categories of personal information we collect about you, and the purposes for which we use such personal information.Disclaimer: Kustomer only contacts candidates from company email addresses ending in kustomer.com and does not seek funds from candidates in any circumstances.
What this role is, and what else it is called
Employers in the UK advertise this kind of work as Web Developer, Software Engineer, Software Developer and PHP Web Developer too, so it is worth searching more than one wording. It is a mid-level Software Engineering role in the UK, advertised as fully remote, so it is open to candidates working from home.
About hiring at Kustomer
Kustomer has 1 other live technology role on its careers page. Elsewhere in its adverts Kustomer asks for MongoDB and Kafka. See all Kustomer roles, salaries and stack.
How this role compares to the market
1,968 live UK roles list Python right now, from 583 employers. The median advertised salary is £80,000; 30% are advertised as remote. Browse Python roles.
1,265 live UK roles list JavaScript right now, from 507 employers. The median advertised salary is £50,000; 33% are advertised as remote. Browse JavaScript roles.
Market figures are today's snapshot of live UK roles on employer careers pages; see hiring trends.
Technologies mentioned
Detected on Kustomer's careers page. ProdReady Recruitment lists this vacancy as an aggregator and is not the employer; applications go to the employer's own site.