Software Engineer, Site Reliability

Contract Type: Full-time Employee

Salary Range: 6,000,000 ~ 12,000,000 JPY

At Sales Marker, our mission is to create a world where all people and companies can challenge themselves beyond existing boundaries. We are one of the fastest-growing startups in Japan—scaling at more than twice the pace of typical unicorns. Our flagship product, Sales Marker, empowers sales teams to achieve 3 times greater efficiency. In just two years since launch, we’ve achieved 2,000% growth, and today our year-over-year business growth stands at 270%—and this is only the beginning.

Backed by strong financial growth, we’re expanding into a bold portfolio of new products, empowering businesses to grow from every angle: Sales, Marketing, Recruiting, AI agents and so on.
More about us: https://corp.sales-marker.jp/

Our co-founders come from leading global companies and were recognized on the Forbes 30 Under 30 Asia List (2023).

Our Product & Engineering team is proudly global, with members from 24+ countries and backgrounds at top tech companies such as Google, Microsoft, Indeed, Mercari, LINE, Yahoo, and SmartNews etc.

At Sales Marker, you’ll join a global, ambitious, and fast-moving team where your ideas truly shape the future. We’re building an engineering culture around:

• Customer Obsession – solving real problems and exceeding expectations

• Ownership – taking responsibility end to end, across roles and functions

• 10x – aiming for bold impact, moving fast, and disrupting old standards

The Common Foundation team helps engineering teams move faster by providing scalable, reliable, and reusable systems that serve as the platform for product development. The Platform Foundation side focuses on reliability, performance, security, and developer productivity across our cloud infrastructure and Kubernetes platform. We build paved roads, automate operations, and ensure that application teams can ship safely at speed.

We're looking for a Site Reliability Engineer who can own the health and evolution of our platform. You’ll design and operate our AWS and Kubernetes environments, lead reliability initiatives, and partner with product engineers to embed best practices in availability, observability, and performance. You’ll turn complex infrastructure into simple, well-documented, self-service building blocks.

• Operate and improve our Kubernetes platform (EKS), including cluster lifecycle, upgrades, scaling, networking, and multi-tenant isolation.

• Design, provision, and manage AWS infrastructure (VPC, RDS/Aurora, OpenSearch, S3, SQS, Lambda, API Gateway, Batch, Glue) with a strong focus on security, reliability, and developer experience.

• Build infrastructure as code using Terraform and AWS CDK. Establish standards for modules, environments, and change management via GitOps.

• Drive observability end to end: metrics, logs, traces, SLOs, error budgets, and actionable dashboards and alerts in Datadog.

• Partner with backend engineers to improve service reliability, performance, and cost efficiency. Champion best practices in testing, rollout strategies, and production readiness.

• Automate operations and repetitive work with tooling and pipelines. Reduce MTTR with improved runbooks, diagnostics, and incident tooling.

• Lead incident response and post-incident reviews. Raise the operational bar through blameless retros, remediation plans, and reliability roadmaps.

• Strengthen platform security through identity and access control, secrets management, network policies, patching, and vulnerability management.

• Support data workloads and pipelines with robust, scalable infrastructure and monitoring.

• Contribute to platform documentation, paved paths, and self-service developer workflows to accelerate delivery.

Required

• 3+ years in SRE, Platform, or Infrastructure Engineering with production ownership of cloud-native systems.

• Strong experience running Kubernetes in production, including upgrades, scaling, and workload reliability.

• Deep hands-on expertise with AWS services (networking, compute, storage, databases, messaging) and secure-by-default architectures.

• Proficiency with IaC (Terraform and/or AWS CDK), modularization, and environment management.

• Solid observability fundamentals: metrics, logging, tracing, SLOs/error budgets, actionable alerting.

• Proven track record improving reliability, performance, and developer experience in partnership with application teams.

• Experience running incident response and driving post-incident improvements.

• Experience with algorithms, data structures, complexity analysis, and software design.

• Experience in development using one or more of the following languages, C, C++, Java, Python, Go.

Nice to Haves

• Experience with identity and access management patterns, Cognito, JWT, and service-to-service auth.

• Background in multi-tenant architectures, capacity planning, and cost optimization.

• History of handling major incidents at scale and building tooling to reduce MTTR/MTTD.

• Contributions to internal developer platforms, golden paths, or shared libraries.

• Fluency in English or Japanese.

[Front-end]

- TypeScript, React, NextJS;

- Testing: Storybook, jest, playwright;

- Hosting: Amplify;

- Feature flag: Unleash;

[Server Side/Back-End]

- Infrastructure: AWS, EKS, ElasticBeanstalk;

- DB: Aurora, ElasticSearch, Redis;

- Languages: Go, Typescript;

- Analysis environment: Athena, Superset;

- Monitoring: DataDog;

- Others: AWS Lambda, AWS Batch, AWS API Gateway, AWS Glue, AWS S3;

• One of the fastest growing Saas startup in Japan with strong financial growth.

• Innovative new product development and opportunity to build things from scratch.

• Plenty of leadership and career development opportunities.

• Hybrid work environment & full flexible work schedules.

• Global team and English speaking environment.

• Great benefits & perks packages such as Resort Worx, Purchasing Books, Free Weekly Lunch, Offsites, etc.

1. Hybrid Work
   We follow a hybrid work style, combining both office and remote work. Recommended in-office days vary by role. Even when working remotely, we maintain smooth collaboration and communication through tools like Zoom, Google Meet, and Gather.

2. Flex Work
   You can customize your working hours to suit your day. For business and client-facing teams, schedules are often arranged around client meetings.

3. Global Environment
   With team members from over 20 countries, we bring together diverse perspectives and ideas, driving projects forward across languages and cultures in an environment where English and Japanese blend naturally into daily communication.

• Career Page: https://sales-marker.jp/corporate/en/

• Culture Book: https://speakerdeck.com/salesmarker/sales-marker-culturebook-en

• YouTube: https://www.youtube.com/watch?v=Ob8Ds06zwo0

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