Principal Backend Engineer

Remote OK
Full-time
March 18, 2026

Are you looking

To make meaningful changes at the fastest-growing tech company in Japan?
For a fair, highly flexible, inclusive working environment where anyone, regardless of their background, can make an impact?
To build the next bold idea in customer acquisition and revenue growth through conversational commerce technology?
For a place where things are not just fast - but they happen now?

We Are Zeals - “Designing conversations. Driving conversions.”

Zeals is not another chatbot. Our automated chat solution and conversational technology change how consumers purchase or act online. Zeals converts customers who appear "unengaged" into "valuable" through designed chat on Messaging Apps. Using AI-powered, human-designed conversation flows across chat platforms, Zeals enables brands to build personalized, automated conversations with their consumers and develop a deeper understanding of their preferences while creating a delightful, seamless shopping experience. Our last 3 years have been phenomenal. We have captured the heart of many businesses in Japan, with over 480 enterprises relying on our chat commerce offering to boost their mobile business.

The goal is simple: to “revolutionize hospitality on the Internet” by unlocking digital customer service experiences that were limited to physical stores previously.

Just Getting Started…

With more than 480 enterprise companies worldwide already utilizing our product, we are perfectly poised to seize market share and fuel exponential growth in the US market, with an eye on global expansion. Investors have taken note of our potential, leading us to recently secure nearly $40 million in funding, backed by Salesforce Ventures.

As a Principal Backend Engineer at Zeals, you won’t just write code — you will own systems end-to-end, shape our architectural strategy, and influence technical direction across teams. You will be a key technical leader in our backend domain, responsible for designing scalable, fault-tolerant systems that power mission-critical services and accelerate the impact of our conversational commerce platform. This role is not about following roadmaps — it's about creating them. You’ll work across teams to raise the engineering bar, mentor senior engineers, and drive strategic decisions that shape our product and infrastructure for years to come.

What You’ll Do

Drive architecture and design of complex, distributed backend systems with a focus on scalability, reliability, and performance
Lead initiatives to modernize legacy systems and migrate to robust, decoupled services using Golang, gRPC, and REST
Own high-stakes technical decisions, balancing trade-offs and setting standards for software design across teams
Ensure best practices in clean code, DDD, testing, observability, and documentation are deeply embedded in the development lifecycle
Collaborate with engineering leadership, product managers, and stakeholders to align backend capabilities with business priorities
Foster a culture of technical excellence through mentorship, knowledge sharing, and collaborative problem solving
When required, participate in the on-call rotation and act as a technical escalation point for critical incidents

What You’ll Need

Proficiency in development flow based on git and GitHub
8+ years of experience in Software Engineering or a similar role, with preferably experience in Golang
Strong sense of testing, including unit tests and integration tests
Ability to communicate recommendations for improvements on current systems, processes, and services as needed
Exhibit a strong ability to adapt in a dynamic and ever-changing environment
Ability to solve problems, especially to identify the source of the problem, and create and test solutions
Proven team-leading experience with the ability to mentor and guide team members

What Makes You Stand Out

Working knowledge of Docker, Kubernetes, and Clean Architecture
Working knowledge of gRPC and RESTful API
Working knowledge of RDB and SQL
Experience in Google Cloud Platform
Experience in Continuous Integration tools like CircleCI
Experience in issue management systems like Jira
Japanese communication skills
Experience in development using Python, Ruby, NodeJS
Experience in using tracing and metrics in deriving performance optimizations and troubleshooting

Don’t just take our word for it

Zeals has received the LinkedIn Top Startups award twice in a row. We believe this is a testament to our growth and our ability to attract great talents–who could potentially be your colleague!

Our Tech Stack

Backend Languages: Go, Python, Elixir
Frontend Languages: HTML, CSS, JavaScript (TypeScript, React.js, Recoil, Zod, Tanstack, etc)
Mobile Languages: None
Infrastructure: Google Cloud Platform, GCP Pub/Sub, Kubernetes, MongoDB, MySQL, Postgres, BigQuery, Elasticsearch, Qdrant
Configuration management tool: Terraform
CI/CD: Github Actions, ArgoCD, CircleCI
Monitoring: Grafana, GCP Cloud Monitoring, GCP Logging, GCP Cloud Trace, Opsgenie
Data: BigQuery, Parquet, Spark, Scala, Python, dbt
Knowledge Tools: Confluence
Other: GitHub / Slack / Jira
Process: Scrum

Ready to roll up our sleeves

We're obsessed with bringing hospitality to everyone – whether it's our customers or you! You’re an individual with unique needs, and while we may not have ping-pong tables or all-you-can-drink espresso bars to offer, we promise you a once-in-a-lifetime experience and co-workers you’ll be proud to brag about to your friends, family, or anyone you meet the next time you go out! As an employer, we're ready to roll up our sleeves and change the status quo if it means making your experience better.

Salary Range : competitive
Performance review: twice a year
Holidays: 10 days of annual leave in the first year, weekends off, national holidays, summer and winter breaks, and 5 refreshment leave days per year.
Visa support: We sponsor visas for the right candidates.
Flexible working: Highly flexible, remote-first organization (in Japan), Interim work from overseas
Housing allowance (within 1.5KM away from office)
Club activity allowance
Team building allowance and Lunch allowance
Zeals Bar (bi-monthly free-flow beer party)

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For applicants via our CEO Masa Shimizu’s X account:

Please note that if we receive a high number of applications, we may limit the number of candidates selected for an interview with Masa Shimizu as part of the screening process. We appreciate your understanding and thank you for your interest.

APPLY NOW ➜

About ZEALS

Build AI that Brings Japanese Omotenashi to the World

ZEALS is an AI company building intelligent products inspired by the Japanese concept of Omotenashi—anticipating people's needs and delivering exceptional experiences. What began as Japan's leading conversational commerce platform has evolved into an AI-native company developing products across autonomous AI agents and robotics.

Today, ZEALS operates three core businesses:

ZEALS AI Engagement, helping enterprise companies deliver personalized customer experiences through AI.
Omakase.ai, a platform for building autonomous AI agents capable of understanding, communicating, and taking action across voice and chat.
Omakase Robotics, developing a robot-agnostic AI operating system that enables robots to work naturally alongside people in real-world environments.

Together, these businesses share a single mission: creating AI that understands people, acts autonomously, and brings the spirit of Japanese hospitality to both digital and physical experiences.

From Market Leader to AI Pioneer

ZEALS established itself as the market leader in conversational commerce in Japan, working with hundreds of enterprise customers across industries including retail, beauty, travel, finance, and automotive.

Building on years of experience designing AI-powered customer interactions, the company has expanded into generative AI and embodied AI. Omakase.ai quickly gained international recognition after launching as the #1 Product of the Day on Product Hunt, with thousands of AI agents created by users within its first months. Meanwhile, Omakase Robotics is applying the same AI capabilities to the physical world, developing software that enables robots to perform meaningful work in human environments.

With teams spanning AI, machine learning, cloud infrastructure, robotics, and product engineering, ZEALS continues to invest aggressively in technologies that shape the future of intelligent systems.

Building the Future of AI

Rather than treating AI as a feature, ZEALS builds products where AI is the core technology. Engineers work across a wide range of challenging technical domains, including:

Autonomous AI agents
Voice AI and multimodal interaction
Large Language Models (LLMs)
Retrieval-Augmented Generation (RAG)
Distributed cloud infrastructure
Robotics software
Computer vision
Real-time systems

Small, highly autonomous teams own products end-to-end, from research and prototyping to deployment and continuous iteration. Engineers collaborate closely with product managers, designers, and AI researchers to rapidly ship new capabilities and solve real-world customer problems.

A Place to Grow

ZEALS has built a culture around ownership, rapid learning, and continuous experimentation. Employees are encouraged to challenge assumptions, move quickly, and take responsibility for delivering meaningful outcomes. The company also supports collaboration beyond day-to-day work through cross-functional lunches, club activities, social events, and opportunities to connect across teams.

Japanese Language Policy
At ZEALS, the product and technology team members primarily speak English (dev-related discussions happen in English on Github or Slack). There might be occasional discussions in Japanese, but most Slack messages are in English (or both languages).

As for meetings, all dev-related discussions take place in English. Given the above, Japanese skills are not required for most positions in the Product & Technology departments. However, one unique aspect of ZEALS’ culture is the desire to increase teamwork and engage with each other, which is why many Japanese members are working on their English skills while many non-Japanese members also work to improve their Japanese skills.

In order to build a truly global team, ZEALS has many multilingual members that proactively support the rest of the team to ensure smooth communications.

Even outside of the Product & Technology departments, all important company-wide announcements are made in both English and Japanese. For example, hiring announcements, new product launches etc. are generally announced in both Japanese and English.

Also, simultaneous interpretation for presentations at large meetings and events is provided to ensure that everyone gets the information they need.
Paid Leave
- All Japanese public holidays off
- 10 days of PTO (awarded 3 months after joining) in the first year
- 5 refreshment leave days per year
- Summer Holidays, Year-end Holidays, Childcare Leave, Congratulations/Bereavement Leave
Benefits
Here are some examples of the benefits which full-time employees can receive:

💻 Loaned Laptops

🇯🇵 Translation Support (EN<>JP)

👶 Shorter Work Hours for Employees Taking Care of Children

👶 Parental Leave

👕 Flexible Dress Code

💜 Social Security / Insurance Benefits Included

🏥 Healthcare Insurance, Periodic Health Checks

💚 Pension Insurance

🚃 Commuter Reimbursement
Remote Work
Although ZEALS requires you to either be in or relocate to Japan, once you’re here, you can choose whether you work from home or in the office.
- Full-time employees in Japan can work from home or come to the office. Transportation reimbursement to and from the office is available and people living close to the office can receive a housing allowance.
- If you’re not based in Japan yet, you can work from overseas while we help you obtain a Japanese working visa.
- Work from your home country 2 months per year.
Work style
ZEALS is flexible when it comes to working hours. They have core time from 1:00pm to 3:00pm JST, but otherwise you’re free to set up your day however you want to meet the monthly working hour requirements.
Values

FROM ZEAL

< Passion >
Good things come from giving it your all

BET ON PARADOX

< Unorthodox >
Never settle for the established norm

UNITED WILL

< Team >
Teamwork is the heart of achievement

Office

The ZEALS office is in the heart of Tokyo, situated in Meguro, near Gajoen, a famous hotel known for hospitality. You can work from the office at a desk as well as use small booths or meeting rooms. You can hook your laptop to large screens and sit in Ergohuman chairs. Lounge areas and standing tables are also available. Everyone is free to choose the work style that works best for them, either full-remote or in the office.